Abstract Book
OLC2021 Okinawa

CONTENTS

List of Presentations (Click # to jump to the abstract)
Tutorial Abstracts
Oral Abstracts
Poster Abstracts

List of Presentations
Tutorials

T1

Ingo
Dierking

University ofManchester

Alternatives to ITO: concepts and material
performance

T2

Claudio
Zannoni

Universita' di
Bologna

Computer simulations and our understandingof liquid crystal behavior

T3

Slobodan
Zumer

University of
Ljubljana

Optical imaging of complex topological defectstructures

T4

Pawel
Pieranski

Université ParisSaclay, France

Collisions of topological defects

T5

HiroshiYokoyama

Kent State
University

Pancharatnam-Berry Phase and Patterned
Photoalignment

T6

Iam Choon Pennsylvania State Liquid crystalline chiral photonic crystals for
Khoo
University,
ultrafast (linear and nonlinear) photonics

List of Presentations
Oral Presentations
PlenaryPL1

Sin-Doo Lee

Plenary

PL2

Keynote

K1

Keynote

K2

KeynoteK3

Liang-Chy
Chien
Ivan
Smalyukh
NelsonTabiryan
Miha Ravnik

Keynote

K4

Keynote

K5

Keynote

K6

Keynote

K7

Keynote

K8

Keynote

K9

InvitedIndustry
InvitedIndustry
InvitedIndustry
InvitedIndustry
InvitedIndustry

II1

Invited

I1

Takahiro Seki

Invited

I2

MarcinMuszyňski

Invited

I3

Guilhem Poy

Invited

I4

Inge Nys

Invited

I5

Invited

I6

EtienneBrasselet
Hsiu-Hui
Chen

II2
II3
II4
II5

Oleg
Lavrentovich
Antonio
Martins
Figueiredo
Neto
Wei LeeMaria Helena
GodinhoShunsuke
Kobayashi
Amy Shen
Hisao
Inokuma
MichioKitamura
Yukito Saitoh
Takahiro
SasakiChristianWeickhmann

Toward New Applications of Reactive Mesogens for
Quantum-Dot Displays and Anticounterfeiting
Laser speckle reduction solution with a liquid
crystal diffuser
Guiding optical solitons by liquid crystal topology
Giant Optical Nonlinearity
Liquid crystal metamaterials for light guiding
Photopatterned liquid crystal elastomers to control
microparticles and living tissues
Effect of the presence of the dye Sunset Yellow on
the stabilization of the amphiphilic-lyotropic
uniaxial and biaxial nematic phases
Liquid Crystal Film on a Single Substrate for
Biosensing
Cellulose nanocrystals (CNCs) colloidal liquid
crystals in water: slight changes, huge differences
Dynamic Retarder for Asymmetric OpticallyCompensated LCDs
Microfluidic shearing and extensional flows on thealignment of cellulose nanocrystals
WONDERLITERDx - Light control window for
automotive glazing
Numerical Modeling for Design and Development of
LC Optical Devices
New Brightest Transparent Screen Using Tilted
Cholesteric Liquid Crystals for Rear Projection
Development of Full Color Transflective andReflective IGZO-TFT LCDs with Twisted-VA Modes
Application of Liquid Crystal Materials in theMicrowave and Millimetre Wave Range for 5G andSatellite Communication Antennas
Photo-triggered mass transport driven from thefilm surface
Opticaltomographyof
momentum-resolved
emission of dye-doped monocrystalline blue phase(I)
Optical solitons and chirality-enhanced nonlinear
optical response in frustrated cholesterics
Multistablering-shaped
liquidcrystalconfigurations through patterned planar photoalignment
Imprinting the vectorial nature of light in liquid
crystals
Synthesis and Characterization of Photochromic
Controllable
Mesomorphic
Diarylethene
Derivatives

Invited

I7

Masaki Hada

Invited

I8

Guang Chu

Invited

I9

Invited

I10

Invited

I11

RumikoYamaguchi
Tigran
Galstian
Masahiro
Funahashi

Invited

I12

Janusz Parka

Invited

I13

YasushiOkumuraInvited

I14

Invited

I15

Invited

I16

Kenji
Katayama
Hiroyuki
YoshidaKoki Sano

Invited

I17

Contributed

O1

Contributed

O2

HiroyaNishikawaContributed

O3

Contributed

O4

Contributed

O5

Jun-ichiFukudaAkihikoMatsuyamaJun
Yamamoto

Contributed

O6

Contributed

O7

Contributed

O8

Sayuri
Hashimoto
Kenji
UrayamaJun Yoshioka

Contributed

O9

Makina Saito

Contributed

O10

Takeaki Araki

Contributed

O11

Contributed

O12

Hirotsugu
KikuchiShizuka Anan

Daigo
Miyajima
Shohei Saito

Ultrafast collective motions of liquid-crystalline
azobenzene molecules observed by ultrafast timeresolved electron diffraction
Liquid Crystal Colloids Printing for Customtailored Photonics
Quasi Twisted Nematic Mode Using Asymmetry
Polar Anchoring in Hybrid Aligned Cell
In-fiber switchable polarizer by capillary-aligned
liquid crystals
High open circuit voltage in double chiralferroelectric liquid crystals comprising an extended
p-conjugated unit
Hyperbolic Metamaterials with Nematic Liquid
Crystals and Dye in Spontaneous Emission
Engineering
Observation of Polymer Structure and Electric-field
Response of Liquid Crystal Director in Composite
Films Consisting of Liquid Crystal and Highly
Oriented Polymer
Photocontrollable Crystallization at the Topological
Defect of a Liquid Crystalline Droplet
Optical Characterization of the (211) Twin in
Cholesteric Blue Phase I
Dynamic Photonic Crystals Consisting of Inorganic
Nanosheets and Water
Bulk Photovoltaic Effect for Polar Columnar Liquid
Crystals
Light-melt adhesives: Structural design andadhesive performances
A Photovariable
Capacitor with Enormous
Capacitance Tunability Realized by A Polar
Nematic Fluid
Lattice orientation of cholesteric blue phases
imposed by planar surface anchoring
Theory of aqueous liquid crystals
Flow induced deformation and orientation of
micelles in phantasmagoric nematic liquid crystals
near continuous I-N phase transition
Formation of surface structures by photoinduced
molecular diffusion
Soft Elasticity Effects in Nematic Elastomers
Revealed by Various Types of Deformation
Marangoni convection driven by temperature
gradient near an isotropic-nematic transition point
Development of novel spectroscopy systems todirectlyobservemicroscopictranslational
molecular dynamics in various liquid crystal phases
A simple molecular model showing ferroelectric
nematic order
Controlling the temperature range of ferroelectric
nematic phases based on eutectic phenomenon
Development weak anchoring surface for nematic
liquid crystal reorientation modified with silane
coupling reagents

Contributed

O13

Pravinraj
Selvaraj

Contributed

O14

Mareena
AntonyContributed

O15

Contributed

O16

Olena
Iadlovska
Yazi Wang

Contributed

O17

Contributed

O18

Contributed

O19

Contributed

O20

Contributed

O21

Contributed

O22

Kaho Ogata

Contributed

O23

Go WatanabeContributed

O24

Contributed

O25

SamlanChandranThodika
Ryota Ito

Contributed

O26

Contributed

O27

Contributed

O28

Contributed

O29

Contributed

O30

Contributed

O31

Contributed

O32

Kyohei HisanoContributed

O33

Yohei Zushi

Contributed

O34

Yoichi

Shoichi
Kutsumizu
YoshiakiUchidaMasayuki
KishinoTakuyaOhzonoTomoki
Shigeyama

BrechtBerteloot
Piotr Lesiak
Jacek
Szczytko
Migle Stebryte
Artur
Geivandov
HiroshiKakiuchida

Superior electro-optical response in Organic
molecules doped in the nematic liquid crystal
device: present status and future perspectives

Large aperture liquid crystal lens using the
hybrid alignment layer with titanium dioxide
nanoparticle and polyimide composite
Bragg diffraction of light at oblique helicoidal
cholesteric structures
The Two-dimension Diffraction and the Milky
Haze of a Large-scale Topological Defect Array in
Nematic Liquid Crystal
Preferred Photo-Induction of Ia3d Cubic Phase in
ANBC-22/Azo Binary Mixture
Immobilization, Reorientation and Migration ofCholesteric Shells for Photonic Applications
Quantification of internal strain in bent silicone
elastomers via selective reflection of cholestericliquid crystals
Polarized microscopy of domain textures ofnematic elastomers
Super-Monodispersed Cholesteric-Liquid-Crystal
Polymer
Microparticles
with
ThreeDimensionally Controlled Molecular Orientation
Unidirectional alignment of polymer-grafted ZnOnanorods in liquid-crystalline polymer films
A Molecular Dynamics Study of Helical Columnar
Liquid Crystals Based on Propeller-Shaped
Metallomesogens
Nonlinear geometric phase lensing from liquid
crystals
Twisted Nematic Liquid Crustal Device Using
Hydrogen-Bonded Liquid Crystal for Terahertz
Frequency Region
Embedded optical ring resonators based on
photoalignment
Polymerizableself-organizing
photonic
structures based on nematic liquid crystals
Tunable liquid crystal optical microcavities for
topological photonics
Reflective optical components based on chiralliquid crystal for head-up displays
Liquid crystal microlenses based on binary
surface alignment
Selective light diffusion of polymer network
liquidcrystals
formedthroughphotopolymerization induced phase separation
by nonuniform photoirradiation
Fast and Slow Tuning of Molecular Recovery
Responseof
CholestericLiquidCrystalElastomers in Layered System
ConfocalObservation
ofReconnecting
disclination lines in Nematic Liquid Crystal
Low voltage fast driving of vertical aligned

Takanishi
Contributed

O35

Yuji Sasaki

Contributed

O36

FumitoAraokaContributed

O37

Contributed

O38

Nobuyoshi
Miyamoto
Kiyoshi Kanie

Contributed

O39

Shunto Arai

Contributed

O40

Yo Shimizu

Contributed

O41

Keiki
Kishikawa

ferroelectric liquid crystal devices by nano-phaseseparation and gelation of ionic liquid
Near-field
diffraction
fromself-organized
topological defects arrays in nematic liquid
crystals
Helical Nanopores to Induce Chiroptic Function– Use of Empty Spaces Created by Helical
Nanofilaments
Perovskite nanosheet liquid crystal gel withmechanochemical structural color
Magnetic Field-Responsiveness of Lyotropic
Liquid- Crystalline Polymer-Modified Fe3O4
Nanoplates
Ultrathin-film formation of liquid-crystalline
organic semiconductors for high performancetransistors
Photo-induced phase transitions of calamiticdiscotic bimesomorphic azobenzene-triphenylene
liquid crystals
Polarization-Maintainable
Axially
Polar
Ferroelectric Columnar Liquid Crystal Phase
Realized by Introducing Chirality

Poster Presentations
Poster 1: P1~P30[P1]Yamauchi Shogo[P2]

Ryotaro Ozaki[P3]

Andriani Furoida[P4]

Akinori Ooka

[P5]

Atsushi Joto

[P6]

Hidetsugu Kitakado[P7]

Takehiro Yachi[P8]

Chen Chun-Jui[P9]

Fuwa Yudai[P10]

Kensuke Suga

[P11]

Shingo Yoshioka[P12]

Yuji Nakashima[P13]

Koki Sasaki[P14]

Yoshiko Takenaka[P15]

Khoa Le[P16]

removed[P17]

removed[P18]

Trong Nghia Lang

[P19]

Shota Harano[P20]

Keita Saito[P21]

Chikara Kawakami

Development of Novel Chiral Molecules with High
Helical Twisting Power
Analysis of Angular Dependence of Band Edge
Wavelengths in Cholesteric Mirror and Bragg-Berry
Cholesteric Deflector
Aggregation
Enhanced
Room-Temperature
Phosphorescence with Dual Emission from Rod-Like
Gold(I) Complexes
Dynamic coupling of gel network and nematicorientation order
Shape classification of liquid crystal elastomers with
twist director configurations
Mechanoresponsive PDMS that reversibly changes
fluorescence in sub-MPa stress
Dynamic Control of Array Structure Based on Fe3O4
Magnetic Nanoparticles by Hybridization with
Liquid-Crystalline Organic Dendron
Synthesis of Polymerizable Tetrabenzocoronene
Mesogen Carrying with Diacetylenic Side Chains
Mechanical Response of Molecular Orientation in
Liquid Crystal Elastomers Controlled by MultiLayered System
Two-step fluorescence color change of stressresponsive polyurethanes that incorporate a flapping
molecule
Dynamic Coupling in Surfactant Lamellar and
Colloid particles Mixtures
Columnar Nematic Liquid Crystal of Monodisperse
Titanate
Nanosheets
Exchanged
with
Dodecyltrimethylammonium
Photoreduction Synthesis of Gold Nanosheet inHyperswollen Lyotropic Lamellar Phase
Fabrication of nematic liquid-crystal necklaces andtheir physical properties
Iridescent Colors in Aqueous Solutions of Chromonic
Disodium Cromoglycate Doped with Chiral Additives

High-performance liquid-crystal-loaded terahertz
wave variable phase shifter with non-radiative
dielectric waveguide structure
Emitting Color-switching in TN display usingtransparent UV range polarizer
Continuous rotation of a cholesteric liquid crystalline
droplet by a circularly polarized optical tweezers
Specific molecular orientation and structure
induction at the interface between nematic liquid
crystal and azobenzene polymer film

[P22]

Yuri Saida[P23]

Takahiro Yamamoto[P24]

Daisuke Taguchi[P25]

Hirona Nakamura[P26]

Ryota Mikami[P27]

Kamil Orzechowski[P28]

Kentaro Tanaka[P29]

Masaru Inoue[P30]

Hirosato Monobe

Ultrafast time-resolved electron diffraction withdouble-pulse-excitation applied to the light-meltadhesive based on a flapping triphenylene liquid
crystalDevelopment of a photoreversible adhesive with two
adhesion states using poly(methyl methacrylate)containing an azobenzene liquid-crystal plasticizer
showing smectic E phase
Precision polymerization of a degradable block
copolymer containing a nematic liquid-crystalline
polymer blockTwo-dimensional molecular orientation directed byscanning wave photopolymerization with digital lightprocessor
Patterning topological defects in nematic liquid
crystals using area-selective surface modification
Enhanced electric field tunability and thermal
stability of photonic crystal fibers filled with gold
nanoparticles-doped cubic blue phases liquid crystals
Observation of three-dimensional structure inelectro- hydrodynamic convective patterns ofcholesteric liquid crystals by fluorescent confocal
microscopy
Photoinduced Charge Behaviors in a Liquid Crystal
Mixture on Different Measurement Frequencies
Charge Transport Property of Butterfly-like Shape
Liquid Crystals Based Fused-Thiophene as Organic
Semiconductors

Poster 2: P31~P59[P31]

Ryo Kimura[P32]

Ryotaro Ozaki[P33]

Nozomi Sato

[P34]

Hiroyuki Yoshida[P35]

Takuho Naraoka[P36]

Azumi Akiyama[P37]

Akira Shiiyama[P38]

Riko Horiai[P39]

Yanagihara Maki

Viscosity probing function of flapping fluorophores
and their optical properties in a nematic liquid
crystalComparison of Characteristics between Electrosplayed Cholesteric Droplets and Cholesteric Cell
Phase transition mechanism of liquid crystal
revealed by patterned-illumination time-resolved
phase microscope
Polymerization Induced Fluorescence Enhancementof Aggregation-Induced Emission Dye-Doped Liquid
Crystals
Detecting Soft Mode in Liquid Crystal Elastomers by
Dynamic Mechanical Tests in Stretched State
Realization of a Room-Temperature Ferroelectric
Columnar Liquid Crystal by Introducing Branched
Alkyl Chains.
Synthesis of nanosheet liquid crystal/elastomer
nanocomposite by using gel template
Self-organization in a nematic phase of Au nanorods
modified with liquid-crystalline organic dendrons
Optical Properties of Cholesteric-Liquid-Crystal
Elastomers with Precisely Controlled MolecularOrientation by Photopolymerization[P40]

Fukui Naoya[P41]

Kazuki Tanaka[P42]

Adele Parry[P43]

Satoshi Arai

[P44]

Takuya Yamakado[P45]

Sadahito Uto[P46]

Rentaro Yuri

[P47]

Yuji Tsukamoto[P48]

Ito Teruki[P49]

Rumiko Yamaguchi[P50]

Katarzyna Rutkowska[P51]

Tomoaki Konishi[P52]

Hikaru Sanada[P53]

Yumiko Naka

[P54]

Yuki Yamamoto[P55]

Takuto Ishiyama[P56]

Kenji Katayama[P57]

Kodai Miyagi[P58]

Takumi Fujiwara[P59]

Junki Yokota

Cholesteric-Liquid-Crystal Polymer Particles with
Controlled Orientation of Helical Axis and Their
Application to Deformation Analyses
Liquid crystallinity of silylated niobate nanosheets
synthesized by using a degradable polymer gel
Novel Liquid Crystal Droplets for the Detection ofBacterial Toxins
SynthesisofAsymmetricLiquid-Crystalline
Viologen Salts
Ratiometric fluorescent force probe that works inorganogels
Uniformly oriented cast film of hydroxypropyl
cellulose liquid crystal
Improvement of Switching Speed in Liquid Crystal
Millimeter Wave Phase Shifter Under Bias Magnetic
Field
Generation of Focused Vortex Beam by Liquid
Crystal Spiral Zone Plate with Homeotropic andPlaner Patterned Alignment Layer
Reverse mode smart window by UV irradiation
through hole patterned photomask
Elastic constant of Hydrogen Bonded Liquid
Crystals Fashioned Between 4-m-Alkyl Cyclohexane
Carboxylic Acids and 4-n-alkylbenzoic Acids (nBA)Electrically and optically-tuned LC:PDMS photonic
devices
Molecular liquid crystal adhesive that melts bylight: Mechanism elucidation of the photomelting
function
Calamitic-discotic
bimesomorphic
azobenzenetriphenylene liquid crystals : photo-induced phasetransitions of the alkyl homologues
Synthesis of Liquid-Crystalline Viologens Exhibiting
Photo-Responsive Properties
UltrafastTime-Resolved
Electron
Diffraction
Capturing Layer Stacking Dynamics of Graphene
Oxide
Scanning wave photopolymerization: effect ofmolecular diffusion of liquid-crystalline monomers
on polymerization behavior
Controlled Formation of Topological Defects of
Liquid Crystals in Micro-Chambers
Isotropic-nematic phase transitions in binary
mixtures of banana-shaped liquid crystalline
molecules
Electroconvection controlled by patterned electrodes
Nonlinear optical molecular reorientation
oligothiophene-doped fluorinated liquid crystalsofTutorial Abstracts

T1

Alternatives to ITO: concepts and material performance [1]Ingo Dierking1*

1 Department of Physics and Astronomy, University of Manchester, Oxford Road,
Manchester M13 9PL, UK* Ingo.Dierking@manchester.ac.uk

Indium tin oxide (ITO)-free optoelectronic devices have been discussed for a number of years in thelight of a possible indium shortage as demand rises. In particular, this is due to the largely increased
number of flat panel displays and especially liquid crystal displays (LCDs) being produced for homeentertainment TV and mobile technologies. While a shortage of primary indium seems far on the horizon,
nevertheless, recycling has become an important issue, as has the development of ITO-free electrodematerials, especially for flexible liquid crystal devices. We will thus summarize the present situation ofprimary and secondary indium production, the main uses of indium as well as the prerequisites andpossibilities for recycling[2]. The main contenders for new electrode technologies are then discussed,
starting with non-carbon ITO-replacement technologies[3], such as metal nanowires, conductive
polymers and ultra-thin metal films. In the discussion an emphasis will be placed on carbon-basedmaterials for LCDs, including composite approaches. These will include films of single-wall and multiwall carbon nanotubes[4,5], and graphene, graphene oxide (GO) and reduced graphene oxide(rGO)[6,7]. At present, some of these technologies already fulfil the technical specifications demandedfrom ITO with respect to transmittance and sheet resistance, albeit not in relation to cost and large-scale
production. Promising approaches in terms of cost versus performance seem to lie in carbon-based
composite materials, combining nanotubes and graphene with metal nanowires or conductive polymers.
Even once a performance equivalent replacement technology for ITO is found, it is unlikely that we willsee ITO-free devices taking over the market soon afterwards. For this to happen, the new materials
either need to be considerably better or clearly cheaper than ITO, because the latter is, and has been
for many years, the established industry standard with all the necessary production infrastructure andR&D knowledge in place. Moreover, a deviation from this standard will be a slow process that can only
be initiated via a considerable step-increase in performance or cost decrease, or for example via
environmental legislation, or with the development of novel display technologies, which cannot berealised with conventional ITO electrode techniques. One of such technologies could be flexible devices
on polymer substrates, which cannot be processed by ITO sputtering techniques. In this case, solution
processing could pave the way for electrodes either of metal nanowire networks or of carbon-basedmaterials, or indeed composite materials of both. In this case, it is likely that price will be the decisive
factor, which could favour carbon-based technologies. Especially, future large-area applications withenvironmental impact, such as energy saving or energy-harvesting windows, could tip the balance
towards carbon-based electrode materials. Yet, it does not seem likely that within the next few years, adrastic move towards ITO-free technologies will be observed.

References[1] I. Dierking, C - J. Carbon Res. 6 (2020) 80.
[2] D. Fontana et al., Crit. Rev. Environ. Sci. Technol. 51 (2021) 429.
[3] W. Cao et al., J. Photonics Energy 4 (2014) 40990.
[4] L. Hu et al., Chem. Rev. 110 (2010) 5790.
[5] J. Hirotani et al., Top. Curr. Chem. 377 (2019) 3.
[6] Y.S. Woo et al., Micromachines 10 (2019) 13.
[7] Y. Ma et al., Small Methods 3 (2019) 1800199.

T2

Computer simulations and our understanding of
liquid crystal behavior
Claudio Zannoni*
Department of Industrial Chemistry, University of Bologna,
Viale Risorgimento 4, 40136 Bologna, Italy* Claudio.Zannoni@unibo.it

Notwithstanding the scientific and technologic importance of liquid crystals, the relation between
a certain molecular structure and the possibility of forming liquid crystal phases is still far frombeing understood. The first generation of theories and computer simulations of liquid crystals havemade drastic and often contrasting assumptions on the model representation of constituent
mesogens and on the type of intermolecular interactions (e.g purely attractive in Maier-Saupe
type and purely hard repulsions in Onsager models)[1, 2]. Computer simulations of liquid crystals,
that started with simple lattice models, have upgraded over the years to off-lattice models wheremolecules are replaced by relatively simple shape objects endowed with attractive and repulsive
interactions and, more recently, to very realistic fully atomistic models.[3]In this tutorial talk we shall briefly summarize the main features of these categories of models showing
some applications[4-6] and highlighting their strengths and limitations. The contribution of different

interactions to the phase behaviour as well as open problems will be discussed.
References[1]M. P. Allen, Molecular simulation of liquid crystals,Mol. Phys. 117, 2391-2417 (2019).
[2]L. Mederos, E. Velasco and Y. Martinez-Raton, Hard-body models of bulk liquid crystals,J. Phys.
Cond. Matter 26, 463101 (2014).
[3]C. Zannoni, Liquid Crystals and their Computer Simulations. (Cambridge University Press,
Cambridge, 2022).
[4]C. Chiccoli, P. Pasini, C. Zannoni, G. Skacej, H. Yoshida, T. Hiroshima, K. Sunami, T. Ouchi
and M. Ozaki, From point to filament defects in hybrid nematic films,Scientific Reports 9, 17941(2019).
[5]M. Ricci, O. M. Roscioni, L. Querciagrossa and C. Zannoni, MOLC. A reversible coarse grained
approachusing
anisotropic
beads
for
the
modellingoforganicfunctional
materials,Phys.Chem.Chem.Phys. 21, 26195-26211 (2019).
[6]A. Baggioli, M. Casalegno, G. Raos, L. Muccioli, S. Orlandi and C. Zannoni, Atomistic
simulation of phase transitions and charge mobility for the organic semiconductor
Ph-BTBT-C10,Chem. Mater. 31, 7092-7103 (2019).

T3

Optical imaging of complex topological defect structures innematics
Slobodan Žumer1,2*

1 Jožef Stefan Institute, Slovenia
2 Faculty of Mathematics and Physics, University of Ljubljana, Slovenia* slobodan.zumer@fmf.uni-lj.si

Frustrated nematics often described by term topological soft matter in their orientational orderparameter fields exhibit stable & metastable point defects, disclination lines, and solitons. In
such systems often conflicting effects of confining geometries, surface anchoring, external
fields, chirality, and elasticity are the source of frustrations. Basic concepts and approaches
needed to model complex topological structures and predict their optical images will besummarized in the following topics:••••

Constrained nematics: chirality, elasticity, confinement, geometry, anchoring, andexternal fields via phenomenological approach lead to complex structures.
Topology of nematic defects: points, lines, loops, braids, and solitons.
Optical imaging: polarization microscopy and multi photon fluorescent microscopy.
Simulated POM approaches [1-6]: Jones approach, improved ray tracing including
refraction & focusing, beam propagation, diffractive transfer matrix, plane wave
expansion, and numerical solving of Maxwell Equations (FDTD).

The supports by the Slovenian Research Agency (P1-0099) and EU COST action EUTOPIA (CA17139) are
acknowledged.

References[1] R Ondris-Crawford R et al, J. Appl. Phys. 69 (1991) 6380.
[2] P W Ellis et al, J. Phys. D: Appl. Phys. 52 (2019) 213001.
[3] U Mur et al, Liq. Cryst. 44 (2016) 679.
[4] G Poy and S Žumer, Soft Matter 15 (2019) 3659.
[5] G Poy and S Žumer, Optics Express 28 (2020) 24327.
[6] A Nych et al, Nat. Phys.13 (2017) 1215.

T4

Collisions of topological defects
Pawel Pieranski*

Laboratoire de Physique des Solides, Université Paris-Saclay, France* pawel.pieranski@u-psud.fr

Abstract: Since the discovery of liquid crystals, a great attention was paid to the identification of
topological defects which very often play the role of fingerprints allowing to recognize different
mesophases.
In this lecture, after an introduction totopological defects, we will report ona recent progress in studies ofcollisions of nematic monopoles [1]and disclinations. We will outline
methods that allow to generate, setinto motion and bring to collisions
these point and linear defects.

Fig. 1 Topology of disclinations and monopoles

In the case of monopoles, we will show howtocontroltheoutcomeofcollisions:annihilation or avoidance.
In the case of colliding disclinations, we will
point out that the resulting rewiring can becontrolled too.

Fig. 2 Rewiring of colliding disclinations

References[1] P. Pieranski and M.H. Godinho, Physics of the dowser texture in Liquid Crystals – New Perspectives,
ISTE – Wiley (to appear in 2021).

T5

Pancharatnam-Berry Phase and Patterned Photoalignment
Hiroshi Yokoyama

Advanced Materials and Liquid Crystal Institute, Department of Physics, Kent
State University, USA* hyokoyam@kent.edu

The Pancharatnam-Berry Phase (PBP) or the geometric phase of polarized optical waves are an opticalembodiment of a universal behavior of transverse vectorial waves [1]. Unlike the ordinary phasechanges associated with propagation of waves in space, the PBP develops instantaneously upon
encountering anisotropic media according to the internal geometry of the medium. This property
makes the PBP look rather mysterious at first glance.
Liquid crystals as responsive optically anisotropic media offer a unique ground, on which the PBP canbe generated, manipulated and exploited for practical use. Since the PBP does not require a large
optical path length to develop an arbitrarily large phase difference, there arises an engineering
opportunity to replace conventional optics by “thin film optics” and further to open up an entirely new
domain of optical technology employing a new form of optical wave such as vortex waves [2].
The photoalignment is the best suited surface-alignment method for liquid crystals to achieve the PBP
liquid-crystal devices. It is just straightforward, in principle at least, to form microscopically resolvedalignment patterns as required for PBP [3]. We have experienced a great deal of technicalsophistication over the past three decades since its inception in the early 1990’s. Our toolbox is now
well equipped to deal with difficult challenges to realize the potential of PBP.
In this tutorial talk, I try to offer a layman’s overview of PBP and the relevant photoalignment
techniques with a view to lowering the hurdle of entry to this exciting field.

References[1] S. Pancharatnam, Generalized theory of interference, and its applications. Proc. Indian Acad. Sci. 44,
247–262 (1956). https://doi.org/10.1007/BF03046050[2] Y. Shen, Y. et al. Optical vortices 30 years on: OAM manipulation from topological charge to multiple
singularities. Light Sci Appl 8, 90 (2019). https://doi.org/10.1038/s41377-019-0194-2[3] V. Chigrinov, et al. Patterned Photoalignment in Thin Films: Physics and Applications. Crystals 2021,
11, 84. https://doi.org/10.3390/cryst11020084

T6

Liquid crystalline chiral photonic crystals for ultrafast (linear andnonlinear) photonics
Prof. Iam-Choon Khoo
Department of Electrical Engineering
School of Electrical Engineering and Computer Science
The Pennsylvania State University
University Park, PA 16802 USA
E-mail: ick1@psu.edu

Abstract
Bulk/crystalline reorientation by an external field resulting in changes in the opticalproperties of the liquid crystals and trigger the desired operations such as polarization switching
and control in ubiquitous devices. These processes are characterized by response times in the
milliseconds to microseconds time sales and the fundamental optical physics underlying theseprocesses are now quite well understood.
In this lecture, I will focus on the relatively less-explored electronic ultrafast [ps and fs]
response of LC molecules to an optical field and unravel some myths about liquid crystals ingeneral and revealed the uncanny abilities of fully developed cholesteric liquid crystals tomodulate ultrafast laser pulses in particular. Owing to the unique combination of photonic crystal
and liquid crystalline properties, and their extraordinary thicknesses with period number >>1000,
the performance characteristics of CLC as a fully developed chiral photonic crystals in the ultrafast
time scales rival most state-of-the-art materials for all optical self-compression/stretching andpolarization switching of optical vector fields of common (linear, elliptical) or complex(azimuthal, radial) polarization states of picosecond and femtosecond laser pulses.
References
1. I. C. Khoo Liquid Crystals Reviews 6, 53–77 (2018) (2018). DOI: 10.1080/21680396.2018.1509387
2. C.-W. Chen and I. C. Khoo Proceedings of the National Academy of Sciences(PNAS) 2021, 118 (16). https://www.pnas.org/content/118/16/e2021304118

Oral Abstracts

PL1

Title： Toward New Applications of Reactive Mesogens for
Quantum-Dot Displays and Anticounterfeiting
Sujie Kang, and Sin-Doo Lee*

Electrical and Computer Engineering, Seoul National University, Korea*lclab2@snu.ac.kr

Reactive mesogens (RMs) have been widely used for producing anisotropic thermal, optical, andelectrical properties resulting from the liquid crystalline order of monomer units throughpolymerization. The RMs enable to construct a rich variety of self-assembled mesoscopic structuresand phases dispersed within amorphous matrices or on solid substrates so that they open new
applications such as quantum-dot (QD) displays with a wide color gamut and an artificial iris with
self-regulating capacity for a human eye. In realizing the QD displays, uniformly dispersed QDs in ahost medium is one of the critical issues to acquire the homogeneous emission together with the low
light leakage over the entire area of an individual pixel and to suppress the aggregation-induced
quenching as well. Thus, it remains a challenge to achieve highly uniform dispersion of the QDs in
well-defined patterns for light emission with the high intensity the high color purity.
In this presentation, we describe two representative types of new applications of the RMs, one ofwhich is the uniform dispersion of the QDs in the host RM matrix with the molecular order and theother is the coloration technology for anticounterfeiting. Basically, these two examples share common
features of the optical anisotropy inherent to the RMs in solidified films. Further applications of theRMs in biomimetics are also discussed.

PL2

Laser speckle reduction solution with a liquid crystal diffuser

Liang-Chy Chien
Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA

Laser-based displays suffer from speckle noise due to the random inference patterns of scattered coherent
light from rough surfaces. Commonly utilized solution, such as moving diffusers, creates time-varying
speckle patterns that were averaged on the observer’s retina or the image sensor. This solution requires theuse of motorized parts and can be bulky with the potential risk of mechanical failure. Hereby, I will present
a liquid crystal diffuser that reduces speckle noise by over 90%. It is electrically driven, compact, and withno motorized parts. The randomized, time-varying domains with mismatched refractive indices of the liquid
crystals produce varying speckle patterns. A near zero speckle contrast is achieved.

K1

Title：Guiding optical solitons by liquid crystal topology
Ivan I. Smalyukh1,2,3
1

Department of Physics, University of Colorado, Boulder, CO 80309, USA

2

Materials Science and Engineering Program, Soft Materials Research Center and

Department of Electrical, Computer and Energy Engineering, University of Colorado,
Boulder, CO 80309, USA
3

Renewable and Sustainable Energy Institute, NREL and University of Colorado,

Boulder, CO 80309, USA
ivan.smalyukh@colorado.edu
Different types of topological defects and solitons are found in practically all branches of physics, ranging
from optics to fluid mechanics, cosmology, particle physics, and condensed matter. However, solitons ofthese very different types rarely co-exist and interact with each other and with other topological entities, likesingular defects [1-3]. Here we develop a system that hosts co-existing optical solitons dubbed nematicons
or similaritons [2,3] and topological solitonic localized structures or singular defects in the molecularalignment field, including Skyrmions, disclinations and twist walls [1]. We demonstrate a large diversity ofinteractions between such optical solitons and topological solitons and defects. These interactions areenriched by a host of nonlinear effects and the host medium’s tendency to minimize the overall free energy
due to orientational liquid-crystal elasticity when the perturbations of director-field alignment due tonematicons are in proximity to the director field configurations of the topological solitons and defects. Theinterplay of nonlinear effects that leads to the stabilization of these different solitons individually also causes
highly nonlinear responses. Our findings show that such nonlinear interactions yield exceptionally richbehaviors that can be controlled by external stimuli, including light itself, and that may find practicalapplications ranging from beam steering to light localization.
References[1] I. I. Smalyukh. Knots and other new topological effects in liquid crystals and colloids. Rep. Prog. Phys.
83, 106601 (2020).
[2] A. Hess, G. Poy, J.-S. B. Tai, S. Zumer and I. I Smalyukh. Control of light by topological solitons inbirefringent media. Phys Rev X 10, 031042 (2020).
[3] G. Poy, A. Hess, I. I Smalyukh and S. Zumer. Chiral nematic optical solitons. Phys Rev Lett 125, 077801(2020).

K2

Limitations and Opportunities for
the Fourth Generation Optics
Nelson Tabiryan1*, David Roberts1, Michael
McConney2, Jonathan Slagle2, Timothy Bunning2

BEAM Engineering for Advanced Measurements Co.
1300 Lee Road, Orlando, Florida, 32810
2
Air Force Research Laboratories, Wright-Patterson Air
Force Base, OH 45433, USA
1*

info@beamco.com

Diffractive waveplates (DWs), also referred to as geometrical phase optics, or Pancharatnam-Berryphase optics, or polarization gratings, are new, Fourth-Generation optics (4G optics), developed toovercome the size, weight, and efficiency limitations of conventional refractive or diffractive optics,
including those based on metamaterials, and speed limitations of switchable optics technologies [1,2].
DWs, however, have unique features that may appear as limitations for applications involving
unpolarized and spectrally broadband light. Examples of such applications are augmented reality
glasses and adaptive ophthalmic lenses, along with high resolution thin and ultralight spacetelescopes, and even diffractive solar sails.
DWs offer effective means for overcoming those limitations due to absence of scatter inherent tometamaterial optics such as metalenses, and due to versatility in customization of their diffraction
spectra. We will present different designs of DWs and their system that perform focusing, beam
deflection, and more complex beam shaping optical functions in a thin-film format, and we will
discuss large aperture high efficiency broadband imaging systems made possible by the use of DWs.
The maturation of the technology pioneered by BEAM Co. over 20 years ago now is at the stage ofscaling-up production and cost reduction which is being obtained by automation of coating andoptical recording processes. Improvement in fabrication technology are progressing to accommodate
complexity of novel DW optics components requiring “random patterning” for switchable hologramsand beam shapers, spectral customization and multifunctionality, and further enhancement of theircapabilities with reflective geometrical phase optics [3].
Yes, there are issues to resolve and overcome in the development of millisecond-fast, micrometerthin, 1V switchable and practically weightless large aperture optics, but there is no alternative in thehorizon to DWs since “There is no Moore’s Law in Optics” [4].

References[1] Review, Hall of Fame Article: Nelson V. Tabiryan, et al., Advances in Transparent Planar Optics:
Enabling Large Aperture, Ultrathin Lenses, Adv. Optical Mater. 2021, 2001692 (1-24)[2] N. Tabiryan, D. Roberts, D. Steeves, and B. Kimball, “4G Optics: New Technology Extends
Limits to the Extremes,” Photonics Spectra, March, 2017, pp. 46-50.
[3] S.Y. Cho, M. Ono, H. Yoshida, M. Ozaki, Bragg-Berry flat reflectors for transparent computergenerated holograms and waveguide holography with visible color playback capability. Sci Rep.
10:8201, 2020.
[4] P. Daukantas, “No Moore’s Law in Optics,” Optics and Photonics News, 19 September 2019.

K3

Liquid crystal metamaterials for light guiding
M. Ravnik1

1 Faculty of Mathematics and Physics, University of Ljubljana, Slovenia
2 J. Stefan Institute, Slovenia
miha.ravnik@fmf.uni-lj.si

Liquid crystal metamaterials have a potential for a range of optic and photonic applications, as they
can control the flow-of light by the spatially variable material birefringence, which –in principle- caninclude also negative refractive eigen-indices. In this work, we present the control of light by selectedliquid crystal metamaterial structures using FDTD and FDFD based numerical modelling. Specifically,
we show the role of topological defects in liquid crystal metamaterials which we show can perform as
attractors and deflectors for light. Also we demonstrate the emergence of light edge states as
determined by anisotropic metamaterial structures. More generally, this work is aimed at developing
novel tuneable approaches for guiding and controlling the flow of light at the wavelength level.

References[1] A. Pusovnik and M. Ravnik, Flow of light in hyperbolic metamaterials with topological defects,
submitted (2021).
[2] U. Mur and M. Ravnik, to be summited (2021).

K4

Photopatterned liquid crystal
microparticles and living tissues

elastomers

tocontrol

Runa Koizumi12, Taras Turiv12, Sergij V. Shiyanovskii12,
and Oleg D. Lavrentovich123*

Advanced Materials and Liquid Crystal Institute, 2Materials Science Graduate
Program, and 3Department of Physics, Kent State University, Kent, OH 44242,
USA1* olavrent@kent.edu

Controlling spatial location of microparticles and living cells is one of the challenges of modern
technology. Here we demonstrate that photoaligned liquid crystal elastomer (LCE) coatings[1,2] could be used as an effective approach to control dynamically the placement of
microparticles [3] and to control cells in living tissues [4], such as the monolayers of humandermal fibroblasts shown in the figure. The director patterns inscribed into the LCE result in a
deterministic response of the coating profile when activated by temperature, light, or humidity.
The spatially-varying reversible profile is used to move the microparticles in the plane of thesubstrate. Anisotropic swelling of the LCEs in contact with the aqueous cell growth medium
produces surface profiles that are capable toalign the living tissues [4]. The LCE aligns thetissues, causes a strong spatial variation of cell
phenotype, their surface density, number
density fluctuations. It also allows for a fasterdirectional growth of tissues which isimportant for wound healing applications.
The work is supported by Office of Sciences,
Department of Energy, grant DE-SC0019105.
References[1]
G. Babakhanova, T. Turiv, Y. B. Guo, M. Hendrikx, Q. H. Wei, A. Schenning, D. J.
Broer, and O. D. Lavrentovich, Nature Communications 9 (2018) 456.
[2]
G. Babakhanova, Y. M. Golestani, H. Baza, S. Afghah, H. Yu, M. Varga, Q.-H. Wei,
P. Shiller, J. V. Selinger, R. L. B. Selinger, and O. D. Lavrentovich, Journal of Applied
Physics 128 (2020) 184702.
[3]
G. Babakhanova, H. Yu, I. Chaganava, Q. Wei, -H., P. Shiller, and O. D.
Lavrentovich, Acs Applied Materials & Interfaces 11 (2019) 15007.
[4]
T. Turiv, J. Krieger, G. Babakhanova, H. Yu, S. V. Shiyanovskii, Q. Wei, -H., M.-H.
Kim, and O. D. Lavrentovich, Science Advances 6 (2020) eaaz6485.

K5

Effect of the presence of the dye Sunset Yellow on thestabilization of the amphiphilic-lyotropic uniaxial and biaxial
nematic phases
Erol Akpinar1, Nazli Uygur1, Oznur Demir Ordu1, Dennys Reis2, Antônio
Martins Figueiredo Neto2

1 Faculty of Arts and Sciences, Bolu Abant Izzet Baysal University, Turkey
2 Institute of Physics, University of São Paulo, Brazil
afigueiredo@if.usp.br

In the talk we will discuss the interactions of the anionic azo dye Sunset Yellow (SSY) withdodecylalkylammonium bromide (DAABr) surfactants in lyotropic mixtures. In particular the effect of
the addition of the dye in the lyotropic mixture have been investigated for the stabilization of thedifferent lyotropic nematic phases. Sunset Yellow doped mixtures of DAABr surfactants, with different
head-group sizes, were studied by polarizing optical microscopy, laser conoscopy, and small-angle xray scattering. Interactions between ionic species on the micelles’ surfaces affect the stabilization ofdifferent lyotropic nematic phases by modifying the packing of the surfactant molecules in the micelles,
the surface curvature of the micelles, and the micellar shape anisotropy. By modifying those interactions,the stabilization of different nematic phases becomes possible. Moreover, the temperature range of thebiaxial nematic phase in the partial phase diagrams can be controlled. This can be done mainly in twoways, by considering the kosmotropic and the chaotropic properties of the surfactant head groups andof the counterions or ions of the electrolytes present in the lyotropic mixtures: (a) using a surfactant andchoosing ions with different degree of the kosmotropic or chaotropic character with respect to it; or (b)using surfactants with different head-group sizes to change the degree of the kosmotropic or chaotropic
character of the surfactant head group and known electrolyte ion. The latter way was followed in thepresent study. Thus, the interactions between the SSY, which has chaotropic character with two ionicgroups at its periphery, and dodecylalkylammonium bromide surfactants with different head groupcharacter was investigated. It was found that the extent of the interaction of Sunset Yellow with DAABr
surfactant head groups on micelle surfaces affects the stabilization of different nematic phases, bycausing the change in the micellar structural parameters. The results also indicated that the micellesurface curvature should be different in the three nematic phases. The surfactant packing parameter andthe area per surfactant head group should have certain values for the stabilization of the nematic phases,
especially the biaxial one [1].
$ TÜBİTAK, BAP, INCT-FCx, NAP-FCx, FAPESP, CNPq, CAPES.

References[1] E. Akpinar, G. Topcu, D. Reis, and A. M. F. Neto, Journal of Molecular Liquids 318 (2020) 114010.

K6

Liquid Crystal Film on a Single Substrate for Biosensing
Po-Chang Wu1, Chao-Ping Pai1, Fei-Fan Duan1, Mon-Juan Lee2, and Wei
Lee1
1 Institute of Imaging and Biomedical Photonics, National Yang Ming Chiao
Tung University, Tainan 711010, Taiwan
2 Department of Bioscience Technology and Department of Medical Science
Industries, Chang Jung Christian University, Tainan 711301, Taiwan
wlee@nctu.edu.tw

In contrast to the conventional approach entailing sandwiched liquid crystal (LC) cells in the LC–solidinterface techniques for LC-based biosensing, here we alternatively demonstrate a simpler platform forlabel-free and quantitative detection of biomolecules (Fig. 1). This unique LC-on-a-single-substratescheme enables efficient detection of proteins, such as the model protein bovine serum albumin (BSA)[1–4], as well as rapid screening and bioassay of DNA hybridization [1] and cancer markers such as
the carcinoma antigen 125 (CA-125) [2,3]. Experimental results based on three different probe
mesophase systems—namely, nematic [1,2], cholesteric [4], and nematic/polymer [3]—spin-coated ona biomolecule-immobilized glass substrate will be reported to manifest the feasibility for easier andtime-efficient establishment of a biosensing platform. The working principle of both the cell platform
and the LC-on-a-single-substrate scheme stems from the disrupted LC alignment and, in turn, reducedorientational order by the immobilized biomolecules; i.e., the analyte, in the interface. Comparatively
addressed will be the pros and cons of both approaches for application in LC–solid biosensing.

Fig. 1. Steps to fabricate an array of biomolecular samples on a single DMOAP-coated glass substrateand successively layer LC films atop the biomolecular samples with various concentrations.

References[1] W.-L. Hsu, C.-P. Pai, P.-C. Wu, M.-J. Lee, and W. Lee, OSA Technical Digest (2018) JTu3A.3.
[2] P.-C. Wu, C.-P. Pai, M.-J. Lee, and W. Lee, in preparation.
[3] M.-J. Lee, F.-F. Duan, P.-C. Wu, and W. Lee, Biomed. Opt. Express 11 (2020) 4915.
[4] M.-J. Lee, C.-P. Pai, P.-C. Wu, and W. Lee, J. Mol. Liq. 331C (2021) 115756.

K7

Cellulose nanocrystals (CNCs) colloidal liquid crystals inwater: slight changes, huge differences
R.R. da Rosa1, D.V. Saraiva1, A.P. Mendes de Sousa2, P. Silva1, S.N.
Fernandes1, M.H. Godinho1*

1 i3N/CENIMAT, Department of Materials Science, NOVA School of Scienceand Technology, FCT NOVA, Universidade NOVA de Lisboa, 2829-516
Caparica, Portugal.
2
RAIZ - Forest and Paper Research Institute, Aveiro, Portugal.
* mhg@fct.unl.pt

Cellulose nanocrystals (CNCs) are very well known to form aqueous colloidal lyotropic liquid
crystalline phases in water [1]. The colloidal CNCs mesomorphic system is due to the presence ofanisometric nano rods. The formation of colloidal liquid crystals in aqueous solutions was first reported
for rod-like tobacco mosaic virus solutions [2] and in 1949, Onsager [3] used entropic arguments to
explain the formation of a nematic phase from a disorder phase of rods. For CNCs, in addition to thenematic phase, a cholesteric structure was also reported [4]. The formation of tactoids from an isotropic
phase was found to be at the genesis of a high-density cholesteric phase that deposits at the bottom of
the vials. Here, we present the coexistence of a nematic low-density phase coexisting with an isotropic
high-density phase, at the isotropic-nematic phase separation, in CNCs aqueous solutions. Furthermore,
atactoids were observed in the upper birefringent phase that after freeze drying the sample translate intoholes in solid cellulose nanosheets. The negative tactoids present needle-shapes with very low axial
ratios compared with the axial ratio of about 50 presented by the CNCs. The appearance of the nematic
phase inversion and the formation of the atactoids were interpreted taking into account the size and thecharge polydispersity of the samples. Our work opens new horizons on the preparation of liquid
crystalline phases from CNCs lyotropic systems with diverse optical functionalities.
Acknowledgements

This work was carried out under the Project inpactus – innovative products and technologies from
eucalyptus, Project N.º 21874 funded by Portugal 2020 through European Regional Development Fund(ERDF) in the frame of COMPETE 2020 nº246/AXIS II/2017 and by FEDER funds through the
COMPETE 2020 Program, National Funds through FCT - Portuguese Foundation for Science andTechnology and POR Lisboa2020, under the projects numbers POCI- 01-0145-FEDER-007688(Reference UID/CTM/50025), PTDC/CTM-REF/30529/2017 (NanoCell2SEC) and COST Action
EUTOPIA.
References[1] M.H. Godinho, Science 369 (2020) 918.
[2] F. C. Bawden, N. W. Pirie, J. D. Bernal, I. Fankuchen, Nature, 138, 1051 (1936).
[3] L. Onsager, Ann. N. Y. Acad. Sci. 51, 627 (1949).
[4] S.N. Fernandes et al., Adv. Mat., 29(2), 1603560 (2017).

K8

Dynamic Retarder for Asymmetric Optically Compensated
LCDs
Shunsuke Kobayashi1, Atsushi Ikemura2 , Michio Kitamura2
1 Professor Emeritus, Sanyo-Onoda City University, Japan
2 SHINTECH.Inc, Japan*corresponding <lcd.kobayashi@gmail.com>

We report dynamic retarder for asymmetric optically compensated LCDs such as IPS, FFS-LCDs and ECB,VA-LCDs. Fig.1 shows the optically compensated LCDs such as IPS, FFS, and ECB, VA mode, whereretarder( compensator,+A-plate)we used in this research is the same as LC cells for the active LCD and the
dynamic retarder is used by applying voltages for changing its properties. When, the azimuthal angle of LCD
cell’s axis, =  and that compensator (retarder),  =  and they are crossed in the x-y plane and thephase retardation of both elements  = , then the optical system is symmetric [1-3]. Contrary, in the
IPS(FFS) =− the optical system is asymmetric and in the OCB(VA) when − −  the opticalsystem is asymmetric [1-3]; this is done by slating the retarder. All the alterations of (V) are done by
applying voltage to the element; this the meaning of the proposed dynamic retarder [1-3].
In the single cell and the proposed asymmetric optically compensate (OC) IPS(FFS)-LCD, the normalized
output transmission respectively reads:
T1= cos2(2 ) (Normally white) and T2 = sin2(2 + ) (Normally black), and for ECB(VA) -LCD
T1= cos2(2 ) and T2 = sin2(2 + ) respectively.
T 2 =I0 cos2(2 + ) that has a geometrical phase advancement compared to the symmetric and single
IPS(FFS)-LCD whose I1 =I0 cos2(2 ) and two-fold fast speed response in the switching off process. The
similar results were obtained in the asymmetric OC ECB-LCD.
We have developed the computer controlled dynamic retarder equipped with an instrument for measuring
electro-optical performance of the proposed asymmetric OC-LCDs.
The functions of the proposed dynamic retarder are as follows:
1. Commonly in the both of the proposed asymmetric optically compensated system it is possible to control
the starting and ending time of the dynamic retarder,
2. In the T2 of OC-IPS(FFS), real situation is not normally black, however making normally black is possible
with the dynamic retarder; an example is demonstrated in Fig.2, the same example is also in the reference[1].
Transmittance(%)

100
90
80
70
60
50
40
30
20
10
0

Fig. 1 Our optical system

Single pFFS
p-OC-FFS(α=0deg.)p-OC-FFS(α=-7deg.)-10 0 10 20 30 40 50 60

Time(msec)
Fig. 2 Simulated t-T curves

References[1]S.Kobayashi,M.Akimoto,K.Takatoh,H.Sawai,N.Toshima,K.Takeuchi,K.Kotani,M.kaneoya,andH.takatsu,MCLC,594,21-30(2014).
[2]S.Kobayashi,T.Miyama,A.Ikemura,M.Kitamura,H.Akiyama,H.Hasabe and H.Takatsu,ILCC 2018.
[3]S.Kobayashi,T.Miyama,H.Akiyama,A.Ikemura and M.Kitamura,Submitted to SYMMETRY.

K9Microfluidic shearing and extensional flows on the alignmentof cellulose nanocrystals
Vincenzo Calabrese, Simon J. Haward, and Amy Q. Shen
Okinawa Institute of Science and Technology Graduate University, Japan
amy.shen@oist.jp

The hydrodynamic assembly of colloidal rods is an effective strategy for the synthesis of soft materials
with structural anisotropy. In this work, cellulose nanocrystals (CNC) are used as model colloidal rodson two representative microfluidic devices, to probe the role of shearing and planar extensional flows
on the alignment of CNC dispersions [1]. Characterization of the flow field by micro-particle imageve- locimetry is coupled with flow-induced birefringence analysis to quantify the deformation rate–alignment relationship. The deformation rate required for CNC alignment is 4× smaller in extension
than in shear. The birefringence signal derived from the CNC alignment in shear and extension can bescaled on a single master curve using a Peclet number that accounts for the shear and extensional
viscosity of the solvent fluid, respectively. Our results will provide the basis to decouple theorientation dynamics in industrially relevant flows, where a combination of shear and extensional rates
is usually present and interparticle interactions also play a crucial role. Quantification of thedifferences between shearing and extensional kinematics at aligning colloidal rods establishes
important guidelines for the manufacture of structured soft materials.

Figure 1: (Left) Number of aligned rods vs. deformation rate. (Right) Schematic of
the effect of the shear and extensional rate on the orientation angle of a colloidal rod.
References[1] Vincenzo Calabrese, Simon J. Haward, Amy Q. Shen, Effects of Shearing and Extensional Flowson the Alignment of Colloidal Rods, Macromolecules, (2021).
http://doi.org/10.1021/acs.macromol.0c02155.

II1

Title ： "WONDERLITE®Dx" - Light control window for
automotive glazing.
Hisao Inokuma

New Product Technology Group, Technology office, Automotive company,
AGC Inc.
* hisao.inokuma@agc.com

AGC has launched light control window "WONDERLITE®Dx”. It has been adopted to automotive
panoramic roof. PDLC (Polymer Dispersed Liquid Crystal) film, used as a light control material, isintegrated to laminated glass and it is world first adoption of PDLC as automotive exterior window for
mass-produced car.
Light control window has switchable function between transparent state and opaque state. When it isapplied to automotive roof, we can get both high exhilaration and privacy and it contributes to cabin
comfort. Characteristic of PDLC is high switching speed, so it brings sense of wonder. Actually, very
positive feedback was given from the market.
In order to realize commercialization, of course liquid crystal material itself is required to have highperformance (optical performance, high switching speed, high durability and so on), but specificationof automotive manufacturer is focused on laminated glass, as final product. So laminated glass designis also important. For example, automotive window is 3D curved glass, so adaption to 3D shape is oneof important point.
AGC has already launched SPD (Suspended Particle Dispersion) typelight control window [1], and has knowledge of product design, glassa

structure, film integration technology, lamination process etc. By
combination of PDLC material and glass technology, we could reach tomeet requirements of automotive manufacturer.
In this paper, we introduce mainly the performance, value ofb

WONDERLITE®Dx, and total product design of laminated glass whichlight control film is integrated, in order to meet requirement for
automotive exterior glazing.
Fig. 1 Appearance of
WONDERLITE®Dx
a: Off state b: On state

References[1] Y. Masaki, H. Inokuma, S. Miyasaka, T Aoki, T. Hamano, Reports of the Research Laboratory, Asahi
Glass Co., Ltd., 65 (2015) 10.

II2

Numerical Modeling for Design and Development of LC
Optical Devices
Michio Kitamura*

SHINTECH, Inc.
*kitamura_ds@shintech.jp
LCs are widely used in every type of displays such as screens of TVs and smart

phones. Their unique electro-optic properties also make them a useful material for non-display applications
such as SLMs (spatial light modulators) and beam steering devices.
The simulation estimating the final performance and optimizing the design parameters is indispensable
technique in designing and developing the LC devices and it facilitates clarifying causes of defects in
production process of them. Recent progress in the computer technology makes the simulation reliable anduseful. I would like to insist on the necessity and the effectiveness of the computer simulation with someexamples carrying out a commercial simulator package [6].
The simulator consists of two major functions, which determines the orientation and behavior of thedirector under the given electric field by the numerical calculation based on the continuum theory [1,2], andwhich evaluates the optical response of the director model aligned by the first function solving Maxwell
equation of the electromagnetic field. Fig.1 shows a directoralignment calculated by FEM in the three-dimensional model of an
FFS cell. Its viewing performance may be evaluated by thetransmission matrix algorithm [3,4], which represents the polarization
Fig.1. Director orientation of FFS cell.

propagation in the optically anisotropic medium. Fig.2 shows the

direction of light emitted from an LC polarization grating in a non-mechanical beam steering device of which
optical configuration is illustrated in Fig.3. The azimuth of the nematic director varies 180 degrees uniformly
during a period of 2m. The configuration repeats periodically along the x-direction. The optical calculationis performed by the algorithm called RCWA, in which both the dielectric function  ( x) and theelectromagnetic field E ( x ) are expanded in Fourier series and coupled together through Maxwell equation.
(a)

(b)

Fig.2. Transmittance vs. direction regarding the incidence of(a)left-handed and (b)right-handed circularly polarized light.

Fig.3. Optical configuration of PG.

Examples of the application of the simulation in design process of LC optical devices will be presented in
the session. The theoretical foundations of the algorithms will be reviewed briefly.
References[1] F.M. Leslie, Quart. J. Mech. Anal. 19. (1956)357.
[2] L. Ericksen and J.L. Arch, Ration. Mech. Analysis 23, (1966)266.
[3] M. Kitamura, Ekisho, in Japanese, 11, (2007)71.
[4] D. Berreman, J. Opt. Soc. Am., 62, (1972)502.
[5] M. Navier and E. Popov, “Light Propagation in Periodic Media”, Marcel Decker, Inc.
[6] LCD Master, SHINTECH, Inc. https://shintechoptics.com/

II3

New Brightest Transparent Screen Using Tilted CholestericLiquid Crystals for Rear Projection
Yukito Saitoh*, Hirofumi Toyama, Takahiro Hayashi, Satoshi Kuniyasu,
Mitsuyoshi Ichihashi, and Yoji Ito
Display Materials Research Laboratories, FUJIFILM Corporation, Japan* yukito.saito@fujifilm.com

Abstract: We have developed a new brightest
transparent screen using diffraction andscattering by tilted cholesteric liquid crystals. It
controls the direction of a rear projection light torealize both high brightness and transparency.
We expect that it could expand outdoor AR
applications for stores and vehicles.
Transparent screen displays are in highdemand for augmented reality (AR) use of alarge number of viewers. A rear projected type ispreferable for outdoor use where a projector
light is from indoor projector. However, aconventional scattering type transparent screen
has a tradeoff between brightness andtransparency.
We have developed a new transparent screen
realizing high brightness and transparency, byusing tilted cholesteric liquid crystals in Fig.1.
We controlled the grating pitch of the cholestericliquid crystals to diffract oblique projection
lights to observers without color separation. In
single-pitch grating, a projector light isdiffracted in specific directions according to thevarious wavelengths, resulting in color
separation. To prevent it, we applied thediffraction grating having various grating pitches
distribution. We controlled the cholesteric liquid
crystals grating pitch with a varied distribution
in the thickness direction, by the spontaneousorientation of liquid crystals. We designed thesurface energy at the air interface and at thesubstrate interface independently to achievedifferent tilt angles at the each interface. As
shown in Fig.2, the tilt angle at the air interface
is lower than that at the substrate interface,resulting in larger grating pitch at the airinterface than that at the substrate interface,from 0.9μm to 1.4μm. Thus, all visible lights canbe diffracted to the observer. Also, the wavingalignment generated by self-assembly of liquid
crystals scatters lights to produce an opticallyreal image. As a result, transparent screen
without color separation can be realized.

Fig. 3 shows the projection image (incident lightangle is 45°) and the transparent image of abackground object, comparing our pitch gradienttype and the scattering type transparent screens.
Our screen shows much brighter image andhigher transparency (low haze). We believe that
it is the most appropriate for outdoor AR use
such as store windows and vehicles to project
advertisements.
Projector
light

Tilted CholestericLiquid Crystal

Scattering
Luminance

Low

High

Fig. 1 Conventional type and our proposal
1.4μm

10 mm

Air side

0.9μm

Substrate side
Fig. 2 Cross sectional SEM image
Projection

Transparency

Tilted CholestericLiquid Crystal

Scattering

Fig. 3 Photos of projection and transparent image
References[1] A. Yamamoto, et al, SID Digest 47 (2016) 16.3
[2] Y. Yanai, et al, SID Digest 49 (2018) 70.4
[3] C. W. Hsu, et al, Nature Comm. 5 (2014) 3152
[4] S. V. Shiyanovskii, et al, Proc. SPIE, Liquid
Crystals II, (1998) 3475
[5] S. Arita, et al, SID Digest, 50 (2019) 42.3
[6] H. Toyama, et al, SID Digest, 52 (2021) 50.3

Development of Full Color Transflective and Reflective
IGZO-TFT LCDs with Twisted-VA Modes

II4

Takahiro Sasaki*, Hiroyuki Hakoi, Junichi Hashimoto, Ming Ni,
Masashi Otsubo, Takashi Sato, Shinji Shimada and Kiyoshi Minoura
Sharp Display Technology Corporation, Japan* sasaki.takahiro@sharp.co.jp

In this report, we review our developed transflective and reflective LCD techonlogies, which
provide high quality color image, low power consumption and good visibility under various light
circumstances [1] [2].
We clarified that our developed reflective LCD technology, based on a new twisted-VA mode andan electrode with silver alloy micro reflective structures (MRS), had excellent optical properties suchas high reflectance, high contrast ratio and high NTSC ratio. Flicker-less 1Hz driving was alsoachieved with applying IGZO-TFT technology and optimal designs of the MRS electrode, LC material
and alignment film material. Some prototypes with the reflective LCD technology showed high quality
video image and low power consumption. Considering the visibility in dark environments, wedeveloped a novel transflective LCD technology based on the reflective LCD technology with thetwisted-VA mode. We found that the twisted-VA mode indicated good optical performance when cell
gaps of reflective and transmissive areas were same. Accordingly, between the both areas in a pixel in
our transflective LCD, there was no step which caused instability of LC alignment. In addition,
fabrication process of our transflective LCD became simpler than that of the conventional, which
needed the step between the areas. We successfully introduced the transflective LCD technology intofull color 31.5-inch IGZO-TFT LCDs the mass production of which has been started since 2020.
Figures 1(a) and 1(b) show photographs of the product. We believe that the transflective and reflective
LCD technologies will contribute to expanding a lineup of new LCD applications.

(a)Reflective image(b)Transmissive image

Figure 1. Full color transflective 31.5-inch IGZO-TFT LCD
References[1] H.Hakoi, et. al., Proceedings of IDW ‘19, pp.1411-1414 (2019).
[2] T.Sasaki, et. al, SID 2020 Digest of Technical Papers, pp.882-884 (2020).

II5

Application of Liquid Crystal Materials in the Microwave andMillimetre Wave Range for 5G and Satellite Communication
Antennas
Christian Weickhmann1, Ahmed Akgiray1, Arshad
Mohammed Reza Dehghani1, and Onur Hamza Karabey1

Mehmood1,

1 ALCAN Systems GmbH, Darmstadt, Germany* christian.weickhmann@alcansystems.com

Liquid Crystal (LC) has been subject of research in the radio frequency (RF) community for about
25 years [1]. Various efforts have been undertaken to exploit LC’s unique features to produce tunable
components in the microwave and millimetre wave range. Following about 10 years of research at
TU Darmstadt, ALCAN Systems have developed an LC-based flat panel antenna technology
applicable to frequencies from about 10 to above 77 GHz, currently used for satellite communication(SatCom) antennas and mobile/5G antennas in the Ku, K and Ka band (between 12 and 30 GHz) [2].
Due to the unique properties of LC, the concept can be extended to higher frequencies [3] even into
the THz range.

In this invited talk, well aware of the material, chemistry and optics focused audience, we will visit the
principles of wave propagation in RF circuits and their differences from typical optical applications,and visit the functional principles of array antennas and the benefit of using LC based components
within them. This will conclude with an introduction of the LC antenna concepts used by ALCAN to
enable low cost SatCom and terrestrial communications (such as but not limited to 5G applications).

At last, the particular challenges for LC materials in antenna applications will be discussed. Unlike inoptics, dielectric loss of the material (tanD) plays a relatively big role for antenna applications. This isbecause signal attenuation directly translates into added noise. Lowering the losses lead to surprisingly
low-loss materials with the drawback of very high viscosities, resulting in very long switching times.
A high tunability (that is anisotropy) of the material can reduce device sizes significantly, in turn
reducing metallic losses. And last but not least, managing environmental influences such astemperature variation, will be discussed.
References[1] Jakoby, R.; Gaebler, A.; Weickhmann, C., Microwave Liquid Crystal Enabling Technology forElectronically Steerable Antennas in SatCom and 5G Millimeter-Wave Systems, Crystals, MDPI, 2020.
[2] Wittek, M.; Fritzsch, C.; Schroth, D., Employing Liquid Crystal-Based Smart Antennas for Satellite andTerrestrial Communication, Information Display, Wiley, 2021.
[3] Maune, H.; Jost, M.; Reese, R.; Polat, E.; Nickel, M. & Jakoby, R. Microwave Liquid Crystal
Technology Crystals, MDPI, 2018.

Photo-triggered mass transport driven from the film surface

I1

Takahiro Seki1*, Issei Kitamura, Mitsuo Hara and Shusaku Nagano2

1 Graduate School of Engineering, Nagoya University, Japan
2 College of Science, Rikkyo University, Japan* tseki@chembio.nagoya-u.ac.jp

Most polymer films have a free surface (surface exposed to air). Recent studies have emphasized theimportance of the free surface in many aspects of polymer processing. We have recently shown thatthe free surface plays the critical role in controlling the mesogen alignment of side chain liquid
crystalline polymers (SCLCPs) [1]. A skin layer (typically 20 nm thickness) or inkjet-printed patternat the free surface is able to regulate the mesogen orientation of SCLCP films of micrometers
thickness [2,3]. The mesogen orientation can be switched by the photoresponsive top surface both in
the in-plane [2] and out-of-plane [3] directions.
Another interesting aspect is the surface
effect for the induction of surface morphing.
We

have

recently

demonstratedthephotoinduced Marangoni flow occurs by
UV

light

irradiation

atinkjet-printed

regions, resulting in on-demand inductionof surface morphology at any timing and atselected areas [4]. These results inspired us
to attempt the surface relief grating (SRG)
formation of a light-inert SCLCP film only
from a photoresponsive surface skin layer
prepared by LS method (Fig. 1.) [5]. A

Fig. 1. Schematic of a LC polymer SRG system
possessing a photoresponsive skin layer only at the freesurface.

large mass transfer was actually induced
upon patterned UV light irradiation. It was found that an LS skin layer of Az-SCLCP can induce 20
times thicker mass transfer of the light-inert SCLCP film existing underneath to generate a SRG
structure. This fact indicates that the mass transfer is driven in large part by the surface effect ofMarangoni flow. Thus, a deeper understanding is obtained for our previous results withphotoresponsive SCLCPs [6].
References[1] T. Seki, Bull. Chem Soc. Jpn. (review) 2018, 91, 1026; T. Seki, Polym. J. (Review) 2014, 46, 751; S.
Nagano, Langmuir (Future Article) 2019, 35, 5673.
[2] K. Fukuhara, S. Nagano, M. Hara, and T. Seki, Nat. Commun. 2014, 5, 3320 (2014).
[3] T. Nakai, D. Tanaka, M. Hara, S. Nagano, T. Seki, Langmuir 2016, 32, 909.
[4] I. Kitamura,K. Oishi, M. Hara, S. Nagano, T. Seki, Sci. Rep. 2019, 9, 2556.
[5] I. Kitamura, K. Kato, R. B. Berk, T. Nakai, M. Hara, S. Nagano, T. Seki, Sci. Rep. 2020, 10, 12664[6] T. Seki, Macromol. Rapid Commun. (Review) 2014, 35, 271.

I2

Optical tomography of momentum-resolved emission ofdye-doped monocrystalline blue phase (I)Marcin Muszyński1*, Eva Oton2, Mateusz Król1, Przemysław Morawiak2,
Rafał Mazur2,
Przemysław Kula2, Wiktor Piecek2, Barbara Piętka1, Jacek Szczytko1
1

Institute of Experimental Physics, Faculty of Physics, University of Warsaw,
Pasteura 5, 02-093 Warsaw, Poland
2
Faculty of New Technologies and Chemistry, Military University of Technology, Gen. S.
Kaliskiego 2, 00-908, Warszawa, Poland* Marcin.Muszynski@fuw.edu.pl
Cholesteric blue phase (BP) of a chiral liquid crystal is an iconic example of self-organized
three-dimensional photonic crystal formed by soft matter. Usually BP exists in a narrow temperature
range of 0.5-2.0 K between an isotropic and cholesteric phases, but this can be extended by use ofpolymer network implemented. There are three types of BPs of a different crystallographic symmetries(BP III, BP II and BP I) observed upon cooling. Well aligned and oriented monodomain BP layers are
essential for practical applications1. Common method for examination of homogeneity is observationof so-called Kossel patterns obtained under illumination with monochromatic light. Here we report anovel approach of studying optical properties of monocrystalline BP I (includes Kossel patterns),
which is three dimensional momentum-resolved tomography of the emission. Our samples can be
doped with various luminescent dyes (like P580), which allows for direct observation of the dispersion
relation of light emitted from the inside of the BP.
Optical properties as emission or reflectivity spectra for BP strongly depends on
directionality2,3. The method proposed by us gives direct access to reciprocal space of optical
diffraction. The obtained results are three-dimensional maps in the space of energy and momentum (inbothanddirection). The cross-section of this map in the energyspace reveals presence ofthe photonic gap. On the other hand the cross-section of thespace results in observation of
Kossel patterns for any wavelength within the spectral emission range of the dye with which thesample was doped.
The optical tomography of BPs opens up new possibilities
for research. It allows the study of quality and orientation of thecrystal, determination of the lattice constant with better precision andobservation of full dispersion relation of transmitted or emitted lightby an angle-resolved experiment. It will help in better understandingof the interactions between the light and blue phase and will give theopportunity to observe new physical phenomena, including quantum
ones, related to it.

Fig 1. Kossel patterns obtained by
References
momentum-resolved tomography.
[1] Otón, Eva, et al. "Orientation control of ideal blue phase
photonic crystals." Scientific Reports 10.1 (2020): 1-8.
[2] Kikuchi, Hirotsugu, et al. "Polymer-stabilized liquid crystal blue phases." Nature Materials 1.1 (2002):
64-68.
[3] Yan, Jin, et al. "Angular dependent reflections of a monodomain blue phase liquid crystal." Journal ofApplied Physics 114.11 (2013): 113106.

I3

Optical solitons and chirality-enhanced nonlinear opticalresponse in frustrated cholesterics
Guilhem Poy1*, Andrew J. Hess2, Ivan I. Smalyukh2,3,4 and SlobodanŽumer5,1
Faculty of Mathematics and Physics, University of Ljubljana, Slovenia
Department of Physics, University of Colorado, Boulder, Colorado.
3
Materials Science and Engineering, Boulder, Colorado.
4
Renewable and Sustainable Energy Institute, Boulder, Colorado.
5Jožef Stefan Institute, Ljubljana, Slovenia.
* guilhem [dot] poy [at] fmf.uni-lj.si
12

During the past 20 years, seminal works [1,2,3] by the groups of Prof. Assanto and Prof. Karpierz
have established liquid crystals as an invaluable platform to study spatial optical solitons, whichcorrespond to self-focused laser beams propagating without diffracting thanks to nonlinear opticaleffects. Indeed, liquid crystals are associated with a giant nonlocal response to external fields leading
to the robust formation of accessible optical solitons called nematicons at beam powers of typically a
few mW. Such optical solitons have mostly been studied in achiral nematic liquid crystals with a welldefined uniform far-field optical axis, in which the laser-induced perturbation of the molecularorientational field allows the compensation of diffractive effects. Although a few preliminary works[4,5] have shown the possibility of generating similar self-focused beams in chiral liquid crystals, therole of chirality in the nonlinear optical response of liquid crystals have not yet been fully elucidated.
In this contribution, I will present our recent contribution [6] to this topic: chirality can boost the nonlinear optical response of frustrated cholesterics cells with homeotropic boundary conditions, thus
leading to the formation of optical solitons at lower power than the nematicons of purely achiralsamples. Such solitons are associated with an interesting bouncing pattern thanks to total internalreflections between the confining plates of the sample (see image below). I will explain the origin of
this chirality-enhancement effect based on the formalism of Green functions, and if time allows I will
also present additional applications of this novel physical effect.

Figure: Simulated bouncing optical soliton (in green) in a frustrated cholesteric cell. The red domain
corresponds to the part of the LC bulk with twist distortions of natural handedness.
References[1] M. Peccianti, A. Dyadyusha, M. Kaczmarek, and G. Assanto, Nat. Phys. 2, 737 (2006).
[2] Nematicons: Spatial Optical Solitons in Nematic Liquid Crystals, edited by G. Assanto, Wiley Series inPure and Applied Optics (John Wiley & Sons, Hoboken, NJ, 2013).
[3] M. A. Karpierz, Physical Review E 66 (2002).
[4] F. A. Sala and M. A. Karpierz, Opt. Express 20, 13923 (2012).
[5] A. Madani, J. Beeckman, and K. Neyts, Opt. Commun. 298-299, 222 (2013).
[6] G. Poy, A. J. Hess, I. I. Smalyukh, and S. Žumer, Phys. Rev. Lett. 125, 077801 (2020).

I4

Multistable ring-shaped liquid crystal configurations throughpatterned planar photo-alignment
Inge Nys1*, Brecht Berteloot1, Guilhem Poy2, Jeroen Beeckman1 andKristiaan Neyts1
1 Faculty of Engineering and Architecture, Ghent University, Belgium
2 Faculty of Mathematics and Physics, University of Ljubljana, Slovenia* Inge.Nys@Ugent.be

Patterned liquid crystal (LC) configurations find widespread applications in functional devices such as
lenses, gratings, displays and soft-robots. Photo-alignment at the confining surfaces offers an attractive
way to steer the self-assembly of hierarchical LC superstructures in the bulk [1-3]. By combining arotating planar alignment at one substrate with uniform planar alignment at the opposing substrate,
defects in the LC are usually created. Herein we use projection illumination to define a ring-shaped
photo-alignment pattern at the bottom substrate with a 360° azimuthal rotation (when moving from theinner radius rin to the outer radius rout Fig. 1(a)) [2]. For this alignment configuration, the formation offour different metastable structures is observed:•

structure A in which a ring-shaped

region is formed with an out-of-plane (vertical)
orientation perpendicular to the substrate,•

structure B which has a single

disclination loop and a 180° twist at the inner
region of the photo-patterned ring (r < rin),

Fig. 1 alignment pattern; POM image•

structure C which has no discontinuities but a 360° twist in the inner region (r < rin),•

structure D in which two disclination loops are observed.

Even though the alignment patterns at the top and bottom substrates define planar alignment andinduce twist conflicts, bulk configurations without singular disclinations are also observed.
Discontinuities in the director configuration can be avoided by creating a localized region with close
to vertical director orientation in the bulk (structure A). Moreover, the closed-loop photo-alignment
pattern also allows to avoid disclinations by introducing a twist deformation in the unpatterned inner
region of the circles (r < rin). One disclination line can shrink and thereby induce a 180° twist in thecentral region (structure B) or both disclination lines can dissappear by introducing a 360° twist(structure C).
The LC director configurations are simulated through finite element Q-tensor simulations and theoptical transmission is simulated using a generalized beam propagation method.
[1] I. Nys, et al., Crystals 10 (2020) 840.
[2] B. Berteloot†, I. Nys†, et al., Soft Matter 16 (2020) 4999. (†both authors have contributed equally)[3] I. Nys, Liquid Crystals Today 29 (2021) 65.

I5

Imprinting the vectorial nature of light in liquid crystals
M. El Ketara1, H. Kobayashi2, and Etienne Brasselet 1,*,
1
2

University of Bordeaux, CNRS, France
Kochi University of Technology, Japan* etienne.brasselet@u-bordeaux.fr

Among the properties of light that dictate its mechanical effects, polarization has held a special placesince the mechanical identification of the photon spin by Beth in 1936. Nowadays, little surprise might
be expected from the mechanical action of linearly polarized weakly focused (paraxial) beams ontransparent and homogeneous dielectrics. Still, here we unveil vectorial optomechanical effects
mediated by the material anisotropy and the longitudinal field component inherent to real-world beams.
Experimentally, this is demonstrated by using a nematic liquid crystal that is prone to exhibit asensitive and reversible effect and our results are generalized to vector beams, as depicted in the figure
below. This corresponds to an alternative strategy compared to other approaches of laser processing ofmaterials in presence of structured light fields using glassy or polymeric materials, whose lack ofreversibility prevent from developing single-snapshot imaging of structured light. Our results thus
represent as a first step towards developing liquid crystals based vectorial polarimeters. Also, recallingthat the light-driven reorientation of liquid crystals is related to giant optical nonlinearities, we show
that, in contrast to the usual self-focusing situation studied since the early 1980s, it is possible to create
multiple self-induced lenses from a single beam which appears worth exploring in the context of
spatial optical solitons in liquid crystals.

Illustration of the optomechanical recording ofvectorial optical structures into a liquid crystal layer.

References[1] M. El Ketara, H. Kobayashi, and E. Brasselet, Sensitive vectorial optomechanical footprint of light insoft condensed matter, Nature Photonics 15, 121 (2021)

I6

Title ： Synthesis and Characterization of Photochromic
Controllable Mesomorphic Diarylethene Derivatives
Hsiu-Hui Chen1*, Hao-Chun Yang1, Wei-Ting Ko1, and Kingo Uchida2

1 Department of Molecular Science and Engineering, National Taipei Universityof Technology, No. 1, Sec. 3. Zhongxiao E. rd., Taipei 106, Taiwan.
2 Department of Materials Chemistry, Faculty of Science and Technology,
Ryukoku University, Seta, Otsu, Shiga 520-2194, Japan* hhchen@mail.ntut.edu.tw

A series of photochromic mesomorphic diarylethene derivatives, denoted as compounds 1a-f, weresynthesized and characterized. [1-2] The colorless hexane solution containing 1 turned blue with 330-nm
light and reversed to colorless by visible light at 580 nm. The conversion from the open-ring form to theclosed-ring form reached a photostationary state under UV irradiation, with 99% as closed form 2. The
photochromic behavior of 1 was investigated in solutions and thin films by nuclear magnetic resonancespectroscopy (NMR) and UV-visible spectroscopy. Both open and closed forms showed liquid
crystalline (LC) properties, which was investigated using polarizing optical microscopy (POM),
differential scanning calorimetry (DSC), and powder X-ray diffraction (XRD). The compound 2a withshort methyl group exhibited excimer/exciplex formation as well as aggregation induced emission
phenomena in the THF. Formation dynamics of intermolecular excimer/exciplex was studied by UVvis spectroscopic method.

Scheme 1. The photoswitching of diarylethene derivatives 1.

References[1] M. Frigoli, G. H. Mehl, The Enhancement of Photoswitching in a Diarylethene Derivative by the
Incorporation of Cyanobiphenyl Groups. Chem. Commun. (2004) 818.
[2] M. Frigoli, C. Welch, G. H.Mehl, Design of Mesomorphic Diarylethene-based Photochromes. J. Am.
Chem. Soc. 126 (2004) 15382.

Ultrafast collective motions of liquid-crystalline azobenzene
molecules observed by ultrafast time-resolved electron
diffraction

I7

Masaki Hada1*, Daisuke Yamaguchi2, and Takashi Kato2

1 Faculty of Pure and Applied Sciences, University of Tsukuba, Japan
2 School of Engineering, The University of Tokyo, Japan* hada.masaki.fm@u.tsukuba.ac.jp

We performed ultrafast time-resolved electron diffraction measurements to demonstrate the formationof higher-orientation of the liquid-crystalline (LC) azobenzene molecules on the picosecond timescaleby linearly polarized ultraviolet (UV) pulse [1,2]. The photoisomerization of azobenzene molecules is
the representative dynamic phenomena in soft matter. However, the ultrafast structural dynamics ofthe molecules during isomerization of azobenzene molecules and their subsequent response have notbeen well explored because of their complex and ultrafast nature. We found that the ultrafast
higher-orientation is caused on the timescale of ~100 ps through the trans-to-cis photoisomerization of
the azobenzene molecules. Figure 1 shows the schematic illustration of ultrafast collective motions of
LC azobenzene

moleculesbythetrans-to-cis photoisomerization of aazobenzene molecule. This is the fastest

UV

collective motion observed in themolecules

in

soft

matter.

Ourconsistentwithobservationsaresimplified

molecular

LPUVTop view

100 psSide view

dynamics

Δ<5 ms

calculations that revealed that themolecules are aligned with the laser
polarization axis by their cooperative
motion after photoisomerization. The

Trans

Cis

insight obtained in this study advances
thefundamental

chemistryofphotoresponsive

molecules

inmatterasultrafast

as

well

their

photomechanical applications.

soft
R = C12H25

Fig. 1 Schematic illustration of ultrafast collective
motions of LC azobenzene molecules

References[1] M. Hada, D. Yamaguchi, T. Ishikawa, T. Sawa, K. Tsuruta, K. Ishikawa, S. Koshihara, Y. Hayashi, T.
Kato, Nature Communications 10 (2019) 4159.
[2] M. Hada, Y. Nishina, T. Kato, Accounts of Chemical Research 54 (2021) 731-743.

I8

Liquid Crystal Colloids Printing for Custom-tailored Photonics
Guang Chu*
Department of Bioproducts and Biosystems, School of Chemical Engineering,
Aalto University, Espoo, Finland*chuguang88@gmail.com

Nature’s light manipulation strategies, especially those at the origin of brightiridescent colours, have fascinated humans for centuries. Many arthropods
display polarization sensitive iridescent colours for communication and aid its
camouflage against predators. This phenomenon is due to the hierarchicalBouligand-type structures that exhibit helical organization and periodic surface
structure. Knowledge about the interplay between the morphology, compositionand optical appearance of biological photonic systems can provide inspiration
for novel artificial photonic devices. Inspired by the beetle of Chalcothea
smaragdina, here we demonstrate a scalable route for the manufacture ofcustom-tailored photonic cellulose paper with hierarchical architectures. We
combine the nanoscale self-assembly of cellulose nanocrystal with microscale
imprinted surface grating-like structure, exhibiting dual structural colour thatderived from the helical matrix and circularly polarized light diffraction.1, 2
Besides, we further extended cellulose nanocrystal as ink for transfer imprinting
lithography to present a micropatterned photonic cellulose paper for
retroreflection.3 We disentangle the hierarchical cellulose printing in different
steps: the microscale surface structure of the patterned template, the drying
dynamics of the nanoscale cellulose self-assembly and, finally, the coupled
optical properties of bulk films. The resulting photonic cellulose paper isparticularly important to understand how hierarchy affects the properties ofchiral light-matter interactions in living organism, not only provides inspiration
for designing of bio-mimetic artificial counterparts, but also allows to further
understand their biological significance in nature.
References[1] Chu, G.*; Camposeo, A.; Vilensky, R.; Vasilyev, G.; Martin, P.; Pisignano, D. and Zussman, E.*,
Printing Flowers? Custom-tailored Photonic Cellulose Films with Engineered Surface Topography. Matter
2019, 1, 988-1000.
[2] Chu, G.; Qu, D.; Camposeo, A.*; Pisignano, D.* and Zussman, E.*, When Nanocellulose Meets
Diffraction Grating: Freestanding Photonic Paper with Programmable Optical Coupling. Mater. Horiz.
2020, 7, 511-519.
[3] Chu, G.*; Chen, F.; Zhao, B.; Zhang, X., Zussman, E. and Rojas, J. O.*, Self-Assembled Nanorods andMicrospheres for Functional Photonics: Retroreflector Meets Microlens Array. Adv. Opt. Mater. 2021, 9,
2002258.

Quasi Twisted Nematic Mode Using Asymmetry Polar
Anchoring in Hybrid Aligned Cell

I9

Rumiko Yamaguchi1* and Shunya Kawata2

1 Graduate School of Engineering Science, Cooperative Major in Life Cycle
Design Engineering, Akita University, Japan
2 Electrical and Electronic Engineering Course, Akita University, Japan* yrumiko@gipc.akita-u.ac.jp

A “twisted hybrid aligned (THA) [1]” cell or a “hybrid twisted nematic (HTN) [2]” cell has been
proposed for a low driving voltage. In this study, we have designed the HTN cell using asymmetry polaranchoring strength, that is, strong polar anchoring of the planar surface and weak polar anchoring of thehomeotropic surface. We can obtain the same LC director distribution as that in a conventional 90° TN
cell, therefore, we call the cell a quasi-twisted nematic (Q-TN) cell. LC director distributions and electrooptical properties in the Q-TN cell were numerically analyzed.
Figure 1 shows a schematic model of the Q-TN cell. Azimuthal easy axes of two substrates are
orthogonal and strong (infinite) azimuthal anchoring strength. When the polar anchoring of thehomeotropic surface (Wp_d) becomes lower than critical one (Wc), the tilt angle on the surface is 0°. In
the case of quasi homogeneous cell, Wc is estimated as K11/d [3]. When the high voltage is applied, theLC the LC director configuration becomes the same as the HTN. The LC director distribution isnumerically analyzed by minimizing a total free energy of the cell using a finite difference method. A
transmittance is estimated using Jones matrix, as a function of normalized applied voltage. In this study,
elastic constant ratio K11:K22:K33=1:0.75:1.4 is used, that is very usual nematic LC physical property fordisplay devices. Wc is estimated as K11/d if K33=2K22. Figure 2 shows tilt angle θ and twist φ angle at thecenter of the cell and transmittance in the Q-TN. The LC reorient without the threshold voltage. φ (2/d)
decreases with the voltage rapidly, then the polarization rotation of the incident light does not occur andtransmittance decreases with very low field. The driving voltage V10 is about 0.35Vth (Vth0

Wp_d=Wc)/∆𝜀𝜀𝜀𝜀0 ), comparing to 1.8 Vth in the conventional 90° TN cell.
90,

Wa_d=∞

Wp_0 = Wa_0 = ∞Schematic model of Q-TN cell in offand on states.
Fig. 1

100

(deg)

4

80

Tilt angle (d/2)
Twist angle (d/2)

Q-TN
0

60

90°TN

45

0

1

Transmittance

V/Vth

2

3

40
20

Transmittance %d

𝐾𝐾33−2𝐾𝐾22

φ (d/2), θ (d/2)=π�(𝐾𝐾11 +0

Fig. 2 Tilt and twist angle at the center of the cell andtransmittance in the TN and the Q-TN. ∆n, λ:1st Morgan minimum
condition.

[1] R. Yamaguchi, IEICE TRANS. ELECTRON, E102-C, 810 (2019).
[2] Y. J. Kim and S.-D. Lee, Appl. Phys. Lett. 72, 1978 (1998).
[3] A. Kubono, Y. Kyokane, R. Akiyama and K. Tanaka, J. Appl. Phys. 90, 5859 (2001).

I10

In-fiber switchable polarizer by capillary-aligned liquid
crystalsAbdullah Rahnama1, Tigran Dadalyan2,3, Keivan Mahmoud Aghdami4,
Tigran V. Galstian3,5*, Peter R. Herman1

1 Dept. Electrical and Computer Engineering, University of Toronto, Toronto,
Canada2 Physics Department, Yerevan State University, Yerevan, Armenia
3 Department of Physics, Université Laval, Quebec, Canada
4 Physics Department, Payame Noor University, Tehran, Iran5 R&D Department, LensVector, Quebec, Canada* galstian@phy.ulaval.ca

We present an electrically switchable polarizer that was embedded inside of standard telecommunication
fiber (SMF-28). Following on our prior work [1,2], a periodic array of nanometric sized holes wereopened fully through the fiber cladding by ultrashort pulsed laser nano-exposition. The spatial pitch ofholes (Ʌ = 1072 nm) was selected to generate a second order Fiber Bragg grating with a resonant
reflection at ~1550 nm, exhibiting very small polarization dependence.
The injection of 5CB nematic liquid crystal material (NLC) into the hole array was done via thecapillarity. Due to the elastic energy minimization, the liquid crystal molecules were oriented
predominantly along the long axis of holes that were positioned perpendicular to the propagation
direction of waveguiding light along the fiber axis. This strong anisotropy of the NLC gave rise to highbirefringence in the Bragg resonance (figure 1) resulting in stronger and wider stopbands forming due
to high value of effective refractive index for the extra-ordinary polarized light (e-mode) relative to theordinary polarization (o-mode). The strong Bragg stop band (1552 – 1556.5 nm) for the extraordinary,polarized light further provided high polarization dependent losses on the long wavelength side of theresonance (figure 1), resulting in a strong
extinction ratio of up to 20 dB extending overa ~5 nm band. A moderate insertion loss of<1 dB was noted arising between the twopolarization states of the shifted stopbands.
The spectral responses of the grating followed
the thermo-optic response of the NLC tofurther offer dynamic tuning and switching of
the polarization extinction response without
increase in the insertion loss.

Figure 1. The thermo-optic response of 2nd order hollow FBG (Ʌ = 1072
nm, 1000 nanoholes) filled with NLC showing a series of transmission
spectra recorded for parallel polarization over temperature range of 20°C
to 35°C.

References[1] K. M. Aghdami, A. Rahnama, E. Ertorer and P. R. Herman, "Laser Nano-Filament Explosion for Enabling
Open-Grating Sensing in Optical Fibre," ArXiv Preprint, p. arXiv:2011.14544 (2020).
[2] A. Rahnama, K. M. Aghdami, Y. H. Kim, and P. R. Herman, "Ultracompact Lens‐Less “Spectrometer inFiber” Based on Chirped Filament‐ Array Gratings," Adv. Photonics Res., 1(2), 2000026 (2020).

I11High open circuit voltage in double chiral ferroelectric liquid
crystals comprising an extended -conjugated unit
Masahiro Funahashi1,2*

1 Faculty of Engineering and Design, Kagawa University, Japan
2 National Institute of Advanced Industrial Science and Technology, Japan* Funahashi.masahiro@kagawa-u.ac.jp

The most remarkable characteristic of liquid crystalline (LC) semiconductors is that macroscopicallyhomogenous thin films can be produced by solution processes [1,2]. Our research group synthesized
ferroelectric liquid crystals comprising oligothiophene units and chiral side chains to exhibit a bulk
photovoltaic effect and rotation of the polarized plane of electroluminescence.
Recently we have reported a bulk photovoltaic effect in a polarized smectic phases of chiralphenylterthiophene derivatives (R)-1 and (R,R)-2 (Fig. 1(a)). In the polarized smectic phase, the internal
electric field produced by the electrical macroscopic polarization promoted photocarrier generation andtransport [3,4]. By doping fullerene derivatives in (R)-1, an open circuit voltage over 0.5 V wasgenerated in a symmetrical cell consisting of ITO anode and cathode. By the inversion of the poling DC
bias, the polarity of the photovoltaic effect could be changed [5]. In the polarized smectic phases of thecompound (R,R)-2 doped with fullerene derivatives, the external quantum efficiency exceeded 80 % andthe open circuit voltage reached 1.0 V in a symmetrical cell using ITO electrodes (Fig. 1(b)).

References[1] M. Funahashi, J. Mater. Chem. C 2 (2014) 7451.
[2] T. Kato, M. Yoshio, T. Ichikawa, B. Soberats, H. Ohno, M. Funahashi, Nat. Rev. Mater. 2 (2017)
17001.
[3] Y. Funatsu, A. Sonoda, M. Funahashi, J. Mater. Chem. C 3 (2015) 1982.
[4] A. Seki, Y. Funatsu, M. Funahashi, Phys. Chem. Chem. Phys. 19 (2017) 14446.
[5] Y. Mori, M. Funahashi, Org. Electron. 87 (2020) 105962.

I12

Hyperbolic Metamaterials with Nematic Liquid Crystals andDye in Spontaneous Emission Engineering
Karol Sielezin, Alessandro Pianelli, Rafał Kowerdziej, Michał Dudek,
Marek Olifierczuk, Janusz Parka*

Institute of Applied Physics, Military University of Technology, Warsaw, Poland*corresponding author, e-mail: janusz.parka@wat.edu.pl
Hyperbolic metamaterials (HMMs) are special class of engineered
metamaterials which exhibit hyperbolic dispersion for interactions with electromagnetic
waves, and they possess non-trivial electromagnetic properties depend on the spatial
projection of their nanostructure. Their unique properties such as: negative refractive
index, near-zero and indefinite permittivity or permeability indices, backward wave, create
completely new perspectives of manipulation of electromagnetic radiation [1-3]. In thiswork we investigated hyperbolic metamaterials with nematic liquid crystals (NLCs +Dye) in spontaneous emission engineering. The vacuum isofrequency surface of

propagating waves in an isotropic media is spherical and is given by:𝜔 2
𝑘𝑥2 + 𝑘𝑦2 +𝑘𝑧2 = ( )𝑐(1)

In HMMs which are anisotropic uniaxial media, the tensors ɛ and µ are given by:𝜀̂ = 𝑑𝑖𝑎𝑔[𝜀𝑥𝑥, 𝜀𝑦𝑦, 𝜀𝑧𝑧] (2)𝜇̂ = 𝑑𝑖𝑎𝑔[𝜇𝑥𝑥, 𝜇𝑦𝑦, 𝜇𝑧𝑧] (3)There are two types of HMMs that depend on which components of dielectric tensor are negative – Type I have
one component negative (𝜀 ||>0 and 𝜀 ⊥<0), while the Type II have two negative components (𝜀 ||<0 and 𝜀 ⊥>0).
The most important consequence of unbounded dispersion of Type I and Type II of HMMs is adivergent photonic density of states (PDOS) resulting in an enhancement in the spontaneous emission of
dipole emitters placed in the vicinity of HMM leading to a metamaterial based broadband Purcell effect andin the result the possibility of control of gain/absorption in tunable hyperbolic metamaterials. The idea anddesign of the transducer developed on the basis of the HMM structure with a layer of liquid crystal and dye could
allow to obtain controlled emission enhancement by photon excitation, which is simplified as shown in Fig. 1.

Fig. 1. HMM transducer design with a layer of NLC and dye to achieve emission enhancement.
Properties of HMM cells were simulated and the next check experimentally. Simulations of HMM structure
properties as well as Purcell factor calculations were performed using by the Lumerical Software.The obtained
gain can be described quantitatively using the Purcell factor which could be measured enhancement in the total
fluorescence intensity as well as by Ramann Scaterring Spectroscopy. We propose the constructions of thetransducer based on the multilayered hyperbolic metamaterials Ag/SiO2 structure with an additional layer ofnematic liquid crystals with high optical anisotropy and dye used to control the gain of spontaneous emission
associated with the Purcell effect more than 10 times.
This work has been supported by The National Centre for Research and Development under grant No.
TECHMATSTRATEG1/347012/3/NCBR/2017(HYPERMAT) in the course of "Novel technologies of advanced
materials - TECHMAT-STRATEG."[1] S. I. Maslovski, C. R. Simovski, Purcell factor and local intensity enhancement in surface-enhanced Raman
scattering, Nanophotonics, DOI: 10.1515/nanoph-2018-0190, pp. 1–6, 2019.
[2] A. Pianelli, R. Kowerdziej, M. Dudek, K. Sielezin, M. Olifierczuk, J. Parka, Graphene–based hyperbolic
metamaterials as a switchable reflection modulator, Optics Express, vol. 28, no. 5/2, pp. 6708–6718, 2020.
[3] M. Dudek, R. Kowerdziej, A. Pianelli, J. Parka, „Grafene-based tunable hyperbolic microcavity” Scientific
Reports, Nature, https://www.nature.com/articles/s41598-02080022-9, 2021.

I13

Observation of Polymer Structure and Electric-field Responseof Liquid Crystal Director in Composite Films Consisting of
Liquid Crystal and Highly Oriented Polymer
Yasushi Okumura1, Eiichi Ishida2, Satoshi Niiyama3, Hirotsugu Kikuchi1*
1 Institute for Materials Chemistry and Engineering, Kyushu University, Japan
2 Interdisciplinary Graduate School of Engineering Sciences, Kyushu University,
Japan
3 AGC Inc, Japan* kikuchi@cm.kyushu-u.ac.jp

The composite films consisting of liquid crystal and unidirectionally oriented polymer exhibit lightcontrol function that are transparent without an electric field and become turbid with an electric field.
Since the index ellipsoids of both the oriented polymer and the liquid crystal in the film match wellwithout an electric field, the composite film is remarkably transparent even viewed from an obliqueangle. The film is prepared via photopolymerization-induced phase separation of precursor consistingof liquid crystals, monomers, and a photoinitiator. In this study, the phase separation process and theresulting polymer structure in the composite films doped with fluorescent monomer were observed
nondestructively by using confocal laser-scanning microscope (CLSM). Furthermore, by doping thefluorescent monomer and a dichroic dye together, a relationship between the polymer structure and theazimuthal distribution of liquid crystal director in the film were observed using CLSM equipped with apolarization rotation unit.
It was found that the highly oriented
pillar-shaped structure of polymer-richphase was generated in an initial phaseseparation process, and the observed
image contrast between the polymer
phase and the liquid crystal one increased
with progress of phase separation while
maintaining the pillar-shaped structure. It
is suggested that a highly oriented pillarshaped polymer structure (Fig. 1(a, d)) in
the direction perpendicular to the cell
substrate surface was formed via spinodal
decomposition due to the large anisotropy

Figure 1 XY (a, b, c) planar and XZ (d, e, f) cross-sectional
images of polymer structures (a, d) and azimuthal distributionof LC directors without (b, e) and with (c, f) application ofelectric field to a highly oriented liquid crystal / polymer
composite film.

in the coefficients of the gradient energy and the diffusion.
The initial state of the liquid crystal director in the film was a uniform homeotropic alignment (Fig. 1(b,e)), but it was found that the liquid crystal directors in each domain partitioned by the pillar-shaped
polymer structures were tilted in different azimuthal directions by application of an electric field normal
to the cell substrate surface (Fig. 1(c)). Interestingly, mono-domains were observed in the thickness
direction under an electric field, suggesting that the light control function of this film is due to a newmechanism rather than the conventional transparent-scattering mode by refractive index-mismatching.

I14

Photocontrollable Crystallization at the Topological Defect of a
Liquid Crystalline Droplet
Yota Sakai1, and Kenji Katayama1*

1 Department of Applied Chemistry, Chuo University, Japan* kkata@kc.chuo-u.ac.jp

These days, topological defects in LCs have been paid much attention to because they could potentiallycontrol the structure and motion of LCs. Intentionally formed topological defects by the photo-alignment
layer could control the alignment of LCs and can be utilized for various thin optics. When a droplet isformed with LC, different types of topological defects were formed inside and on the surface. These
droplets and spheres have been studied intensively as an ‘active matter,’ where the object could movearound spontaneously like a living object by external energy sources.
In this study, we accidentally found a unique crystallization phenomenon while studying a new
category of active matters consisted of LCs, which could move around in a surfactant solution due to an
induced convective flow inside and outside the droplets while gradually dissolving into it. We found thephoto-controlled motion of the LC droplets by promoting adsorption and desorption of molecules [1,2]and showed a clockwise/anti-clockwise rotation under the light.[3] During this study, we found a
crystallization of a chemical was triggered by light at the topological defect in a pure LC droplet (Fig.1),
even though the chemical was dissolved outside the LC droplet. Under the light irradiation whose
wavelength matches the absorption of chemicals, a crystal was formed inside an LC droplet. It grew at
the center of the droplet (topological defect) with a branched shape like an ice crystal. This is the first
demonstration of the topology-induced crystallization under the geometrical frustration.

Fig.1 The snapshots of a 5CB droplet in an SDS solution with p-nitrophenol (0.01 wt%) under the onoff operation of the UV light is shown; (a) before irradiation, (b) - (e) 0, 30, 60 and 90 s after the UV
was turned on, (f) - (h) 0, 60, and 120 s after the UV light was turned off, (i) and (j) 0 and 30 s after the
UV light was turned on again.
References[1] Y. Sakai, et al, Soft Matter, 15, 7159 (2019).
[3] Y. Sakai, et al, RSC Adv., 10, 21191 (2020).

[2] Y. Dogishi, et al, Soft Matter, 14, 8085 (2018).

I15

Optical Characterization of the (211) Twin in Cholesteric Blue
Phase I
Hiroyuki Yoshida1*, Yuxian Zhang1,2, SeongYong Cho1, and Masanori
Ozaki1
1 Graduate School of Engineering, Osaka University, Japan
2 Department of Materials Science and Engineering, University of Science andTechnology Beijing, P. R. China* yoshida@eei.eng.osaka-u.ac.jp

Understanding structure formation and related phase transitions is a ubiquitous problem in many
scientific disciplines, with significant academic and practical implications. Recently, resonant X-ray
scattering has shown that the cholesteric blue phase (BP) I with body-centered cubic (bcc) symmetryshows twinning on the (211) plane, which is commonly found in atomic crystals with the same
symmetry [1]. While X-ray measurements can provide high-resolution diffraction data, it is not easy to
perform microscopic observations in a specified area of the sample or in-situ observations while
applying a field. Here, a detailed optical analysis of twinning in BP I was performed through a
combination of wide-field and Kossel pattern observations.
A BP material mixture was filled into a sandwich cell with a cell-gap of ~ 5 μm, andtemperature-controlled to show BP I. Polarized optical microscope images were obtained together
with Kossel patterns using a high-magnification objective lens. Also, an electric field was applied in
the cell-normal direction to investigate in-situ the evolution of twin
domains.
Figure 1 shows Kossel patterns from a monodomain and twinned
BP I with (110) lattice plane orientation. In addition to the four
Kossel lines from (110) planes creating a pattern with two-foldsymmetry, six lines are observed in the twinned domain, attributed
to a shared (211) plane. We discuss how the Kossel pattern can beanalyzed to obtain the twin elements of BP I, and a reveal atwin-induced pinning effect that occurs as the BP I undergoes
electrostriction by an electric field.
Acknowledgements
We acknowledge Prof. Hirotsugu Kikuchi, JNC Corporation and DIC
Corporation for providing materials, and Prof. Jun-ichi Fukuda forproviding the order parameter data of BP I. This work was partly
supported by MEXT KAKENHI (19H02581, 20H00391, 20H04672,
20K21154), MEXT LEADER Program, and NSFC (65005008).
References[1] H. Jin et al., Sci. Adv., 6, eaay5986, (2020).

Figure 1 Kossel patternof a (a) monodomain and(b) twinned BP I.

I16

Dynamic Photonic Crystals Consisting of Inorganic
Nanosheets and Water
Koki Sano1,2*, and Yasuhiro Ishida1
1 RIKEN Center for Emergent Matter Science (CEMS), Japan
2 JST PRESTO, Japan* koki.sano@riken.jp

Structural colors, originating from a photonic nanostructure with a periodicity in thevisible-wavelength range, are ubiquitous from animals to plants. Interestingly, some tropical fish candynamically change their structural colors by modulating the periodic distance of crystalline guanine
sheets cofacially oriented in their cytoplasm. Inspired by such a sophisticated system, we recently
reported that an aqueous dispersion of a tiny amount of inorganic nanosheets (<0.5 vol%) exhibited
freely tunable structural colors [1].
The building block of our dynamic photonic crystal is a titanate nanosheet (TiNS, Fig. 1a),featuring ultra-thin (0.75 nm) and extra-wide (several µm) dimensions [2]. Owing to its dense negative
charges on its surface, the strong electrostatic repulsion works between TiNSs in addition to the vander Waals attraction. These competitive repulsive and attractive forces allow for interlocking TiNSs ina cofacial manner at a fixed relative position, as described in the Derjaguin–Landau–Verwey–
Overbeek (DLVO) theory [1,3]. Therefore, TiNSs form a liquid-crystalline lamellar structure in water,
although the periodicity of as-prepared TiNSs is too small to exhibit a structural color (Fig. 1b, left)[4]. We found that the periodicity could be drastically enhanced up to 675 nm by reducing the excess
amount of ions in the dispersion of as-prepared TiNSs because of the increment of the electrostatic
repulsion between TiNSs (Fig. 1b) [1]. To our surprise, the resultant dispersion composed of >99.5
vol% water and <0.5 vol% TiNSs
exhibited vivid structural colors, which
could be easily modulable from UV (370nm) to even NIR (1,750 nm) regions
upon varying the TiNS content (0.50–
0.09 vol%) (Fig. 1c). The obtained
photonic crystals quickly modulated theirstructural colors upon various external
stimuli, such as temperature, magnetic
field, and pH, because of their fluidity.
Furthermore, we succeeded in fixing thephotonic structure as a hydrogel, so thatthe obtained photonic hydrogel changed
its color in response to a mechanicalFig. 1. (a) Schematic image of titanate nanosheet (TiNS) and (b)force [5]. More recent findings will be expansion of TiNS distance by deionization. (c) Real images ofalso discussed in the presentation.
the dynamic photonic crystals with various TiNS contents.
References[1] K. Sano et al. Nat. Commun. 7, 12559 (2016).
[2] T. Sasaki et al. J. Am. Chem. Soc. 118, 8329–8335 (1996).
[3] K. Sano et al. Nat. Commun. 11, 6026 (2020).
[4] K. Sano et al. Angew. Chem. Int. Ed. 57, 2532–2543 (2018).
[5] K. Sano et al. Angew. Chem. Int. Ed. 57, 12508–12513 (2018).

I17

Bulk Photovoltaic Effect for Polar Columnar Liquid Crystals
Daigo. Miyajima1*

1 Center for Emergent Matter Science, RIKEN, Japan.
* daigo.miyajima@riken.jp

The bulk photovoltaic effect (BPVE) involves direct current generation in noncentrosymmetricsemiconductors or insulators under light irradiation. The BPVE is fundamentally different from theconventional photovoltaic effect observed in p-n junctions. Recently, the BPVE has attracted wide researchinterest due to its unique features, such as being ultrafast responsive, being dissipation-less, and having a
low noise photocurrent. Thus far, the BPVE has been studied mainly for inorganic ferroelectrics such asoxides, chalcohalides and hybrid perovskites, while studies on the BPVE in organic materials are quite
limited.1,2,3 In general, rationally designing such polar organic materials is difficult because molecules
prefer to assemble symmetrically, resulting in nonpolar assemblies.
Recently, we reported a hexagonal columnar liquid crystal with a bowl-shaped π conjugated molecule,subphthalocyanine (SubPc-SC12). Although individual columnar assemblies of SubPc-SC12 are intrinsicallypolar, the as-prepared sample exhibits no SHG signal, indicating that no macroscopic polarization wasdeveloped. On the other hand, just by cooling the sample from its isotropic melt under an application of DC
e-field, the resultant assembly became SHG active. Interestingly, the obtained polar columnar assemblies
exhibited the BPVE over a wide range of wavelengths up to 650 nm (Figure 1). Furthermore, just by
sandwiching this columnar assembly between two ITO electrodes, the resultant device reaches alight-on/off ratio, ILight/IDark, as high as 6.6×103, indicating that the polar columnar assemblies with SubPcs
are promising for photodetectors.4 In this presentation, we also discusse the relationship between BPVE andthe macroscopic polarization developed by SubPc-SC12.5

Figure 1: Schematic illustration of bulk photovoltaic effect for the columnar assembly of SubPc-SC12
References[1] Seki, A.; Funatsu, Y.; Funahashi, M. Phys. Chem. Chem. Phys. 2017, 19, 16446.
[2] Nakamura, M.; Horiuchi, S.; Kagawa, F.; Ogawa, N.; Kurumaji, T.; Tokura, Y.; Kawasaki,
M. Nat. Commun. 2017, 8, 281.
[3] Mori, Y.; Funahashi, M. Organic Electronics, 2020, 87, 105962.
[4] Zhang, C.; Nakano, K.; Nakamura, M.; Araoka, F.; Tajima, K.; Miyajima, D. J. Am. Chem. Soc. 2020,
142, 7, 3326.
[5] Zhang, C. and Miyajima, Manuscript in preparation.

O1

Light-melt adhesives: Structural design and adhesive
performances
Tomoaki Konishi1, Yumi Nakaike1, Mitsuo Hara2, Ryuma Sato3, Yuri
Saida4, Wataru Yajima4, Ryo Shikata4, Masaki Hada4, and Shohei Saito1*

1 Graduate School of Science, Kyoto University
2 Graduate School of Engineering, Nagoya University
3 Cellular and Molecular Biotechnology Research Institute, AIST
4 Graduate School of Pure and Applied Science, University of Tsukuba*s_saito@kuchem.kyoto-u.ac.jp
Light-melt adhesive offers a new application of columnar liquid crystals.1,2 The previously reported
flapping anthracene molecule shows a high cohesive force originating from the tightly stacked V-shaped
columnar p-stacking, while the UV-induced dimerization of the anthracene moieties leads todisorganization of the ordered phase, providing a non-adhesive fluid.1 However, the anthracene-based
adhesive has some remaining problems, which hamper practical applications in industry. To solve theproblems, here we have developed a triphenylene-based light-melt adhesive (TP-FLAP).3 TP-FLAP has
the following advantages: 1) Novel working principle for realizing the UV-induced melting behavior.
Flapping dynamics of the V-shaped molecules is induced by excited-state aromaticity, which leads torapid destruction of the columnar packing without any photoreaction. 2) Spontaneous recovery of theadhesive strength (instant reworkability) by simply stopping the UV irradiation. 3) Large-scale synthetic
approach established by only three-step reactions from a commercially available compound and easy
reprecipitation process. Molecular design, adhesive performance, and the working mechanism revealed
by ultrafast electron diffraction analysis4 will be introduced.

References[1] S. Saito, M. Hara et al. Nat. Commun. 7 (2016) 12094; JP-Patent 6284184 (registered).
[2] D. K. Hohl and C. Weder, Adv. Optical Mater. 7 (2019) 1900230.
[3] S. Saito, Y. Nakaike et al. JP-Patent application 2019-154772.
[4] M. Hada, S. Saito et al. J. Am. Chem. Soc. 139 (2017) 15792.

O2

A Photovariable Capacitor with Enormous Capacitance
Tunability Realized by A Polar Nematic Fluid
Hiroya Nishikawa1*, Koki Sano1,2* and Fumito Araoka 1*

1 RIKEN Center for Emergent Matter Science (CEMS), Japan
2 JST PRESTO, Japan* hiroya.nishikawa@riken.jp, koki.sano@riken.jp, fumito.araoka@riken.jp

In early 2017, a new nematic polymorph with highly polar order has been found in archetypal
molecules, RM734 [1] and DIO [2] which usher in an entirely new era in the history of liquid crystals.
A common significant characteristic of them is a colossal dielectric permittivity (>10,000) in a polar
nematic phase. Needless to say, they have vast potential for innovative applications by the proactive
use of its gigantic dielectric properties. For example, with the aid of the anomalously large dielectric
permittivity, just a usual sandwich LC cell with a micron-gap may work as an electric condenser witha useful capacitance value. In this work, we demonstrate an epoch-making photovariable electriccondenser (PVC) by doping DIO with a photo-trigger molecule, resulting in an extremely wide
phototunability in capacitance between 0.34 µF and 7.0 nF. To the best our knowledge, this is the first
PVC using LC with such a wide capacitance tunability. To prove the usefulness of our PVC, wefabricated an electric sound oscillator using PVC. The sound pitch ranging over the entire range from240 Hz to 10.6 kHz within the human audibility could be controlled remotely, rapidly, reversibly, anddrastically by light stimuli (Fig. 1). Such an unprecedented photo-tunable feature with a fluidic nature
may bring innovation in the state-of-the-art flexible devices, such as for soft robotics, etc. and may
open the new field for applicational uses of LCs other than displays.
Fig.1:
Demonstrationofthephoto-tunable sound oscillator utilizing
PVC. a) Left panel: the appearance ofthe setup built with a timer IC and
PVC, connected to an electric buzzer.
Right panel: the relation between thecapacitance and the generated electricpulses from the oscillator in the initialstate. b,c) Upper panels: PVC upon
UV/VIS illumination, shown with an
expected alteration in the capacitanceand the generated pulses. Bottom
panels: evolution of the output as afunction of illumination time.
Experimental condition: T = 55.6 °C,
UV (365 nm, I = 2.3 mW cm–2), Vis(450 nm, I = 3.0 mW cm–2).
References[1] R. Mandle et al., Chemistry, 23, 14554 (2017).
[2] H. Nishikawa et al., Adv. Mater., 29, 1702354 (2017).

O3

Lattice orientation of cholesteric blue phases imposed byplanar surface anchoring
Jun-ichi Fukuda1*, and Slobodan Žumer2,3

1 Department of Physics, Kyushu University, Japan2 Jožef Stefan Institute, Slovenia
3 Faculty of Mathematics and Physics, University of Ljubljana, Slovenia* fukuda.jun-ichi@phys.kyushu-u.ac.jp

Cholesteric blue phases (BPs) are complex three-dimensional structures that a highly chiral liquid
crystal can exhibit. They are composed by an array of double twist cylinders (in which orientational
order is twisted along all directions perpendicular to the cylinder axis) interwoven by line defects oforientational order (disclination lines). In addition to drawing academic interest as frustration-inducedorder, BPs have been gaining greater attention because of their potential for practical opticalapplications including light manipulation making use of chiral submicron periodic structures. However,preparation of large-scale monodomain BPs, necessary for applications, is still a challenge. Recent
attempts to obtain monodomain BPs rely on rubbed or patterned surfaces, and the understanding of the
behavior of BPs in contact with such surfaces is important. Motivated by a recent experimental study
clarifying the lattice orientation of BPs imposed by planar surface anchoring [1], we numericallyinvestigate the behavior of BPs in contact with surfaces enforcing planar anchoring.
Our work uses the Landau-de Gennes theory describing the orientational order of the liquid crystal
by a second-rank tensor χij and the free energy of the liquid crystal as a functional of χij with the bulk
and the surface contributions. We focus on the following two cases that are commonly realized inexperiments: (i) Blue Phase I (BP I) with its (110) plane parallel to the surfaces, and (ii) Blue Phase II(BP II) with its (100) plane parallel to the surfaces. By systematically evaluating the free energy as afunction of the angle θ between the lattice axis of BPs and the easy axis of the surface anchoring, wefind that in both cases BPs adopt a specific lattice orientation with a single value of θ, and that theanchoring strength on the order of 10-5 J m-2 is sufficient to lock the lattice orientation. Our numericalfindings are consistent with some of the experimental observations, but not all; the experimental θ
depends on the thermal process. Therefore, how BPs orient in response to the treatment of the surfaces
still needs further theoretical and experimental studies.
This work is supported by JSPS KAKEHHI (Grant numbers: JP17H02947 and JP21H01049) and JSPS
Bilateral Joint Research Project between Japan and Slovenia.
References[1] M. Takahashi et al., J. Phys. D 51 (2018) 104003.
[2] J. Fukuda and S. Žumer, Phys. Rev. Res. 2 (2020) 033407.

O4

Theory of Aqueous Liquid Crystals
Akihiko Matsuyama

Department of Physics and Information Technology, Kyushu Institute ofTechnology, Iizuka, Fukuoka, Japanmatuyama@bio.kyutech.ac.jp

Recently water-dispersible liquid crystalline molecules have received significant attention
as new materials for not only display but also food science and biomaterials [1]. Typicalexamples are chromonic liquid crystals, graphene oxide, and surfactant-covered carbon
nanotubes, etc.
In this paper, we introduce a mean-field theory to describe nematic (N) ordering and phaseseparations in aqueous low-molecular-weight liquid crystalline molecules (LCs). We consider
a physical bonding (or a hydrogen bonding) between LC and solvent (water) molecules. Our
theory predicts that the hydrogen bonds between the unlike molecules stabilize the N phaseand take place novel phase separations on the temperature-concentration plane. As increasing
the number of functional groups on the LCs, capable of forming the physical bond with thesolvent molecule, the stable N phase region is broadened on the phase diagram. We also finda miscibility window of the N phase and closed-loop coexistence curves with upper and lower
critical solution temperatures near the N phase [2].

Figure 1. Schematic representation of thedispersion of the m-clusters with solvent
molecules. Each LC molecule carries f(=4)
identical functional groups capable of forming aphysical bond with the solvent molecule. The open
circles show the free solvent molecules and theclosed circles show the solvent molecules bonded
on the functional group. The number on the LC
molecule is the number m of the bonded solvent
molecules, which become a part of the LC
molecules.

Fig.1
References[1] A. D. Rey, Soft Matter, 6, 3402-3429 (2010).

[2] A. Matsuyama, submitted (2021).

O5

Flow induced deformation and orientation of micelles inphantasmagoric nematic liquid crystals near continuous I-N
phase transition
Jun Yamamoto1,2*and Nozomu Takahashi1,2

1 Department of Physics, Graduate School of Science Kyoto University, Japan
2 JST CREST, Japan* yamamoto.jun.4r@kyoto-u.ac.jp

In this paper, we investigate the flow induced the shape deformation and the orientation rotation
motion in phantasmagoric nematic liquid crystals in the vicinity of the continuous Isotropic (I) - Nematic(N) phase transition.

We measure the response of the flow birefringence under applying sinusoidally

modulated flow field. For the phantasmagoric liquid crystal systems, shape transformation of theamphiphilic supermolecules promotes I-N phase transition in addition to the order-disorder transition
for the orientation of super molecules. In the isotropic phase, order parameter fluctuation can beobserved by the depolarized VH scattering. It is evident that the relaxation frequency linearly diverges
toward I-N phase transition temperature (TIN), and the critical temperature T* is almost equivalent toTIN, TIN-T*~0. It is confirmed that the I-N transition shows the continuous phase transition. On the otherhands, even in the isotropic phase, the susceptibility of the external field should diverge near continuous
I-N phase transition, due to the large order parameter fluctuation and the critical slowing down near TIN.
External flow should couple with the orientation and shape of the micelles. It is obvious that thelarge flow induced birefringence can be widely identified until T- TIN ~10°C. We measure the responsetime in the flow birefringence under the sinusoidally modulated flow field and discuss the origin anddynamics of the flow induced birefringence. The response time of the flow birefringence is 3-order
slower than the relaxation time of the order parameter fluctuation observed in DLS measurement evenin the isotropic phase near continuous I-N transition point.

Flow Birefringence

Flow BirefringenceFig.1 Temperature dependence of flowbirefringence for φ=8% and α=2.2. Bluecircles indicate the amplitude, and red circles
phase shift.

Fig.2 Temperature dependence of flowbirefringence for φ=8% and α=2.6. Isotropic
phase is always stable, but the criticalphenomena evidently observed in wholetemperature range.

This work was supported by JST CREST Grant Number JPMJCR2095, Japan.

O6

Formation of surface structures by photoinduced molecular
diffusion
Sayuri Hashimoto1,2, Norihisa Akamatsu1,2, Shoichi Kubo1,2, Atsushi
Shishido1,2*

1 Laboratory for Chemistry and Life Science, Institute of Innovative Research,
Tokyo Institute of Technology, Japan
2 Department of Chemical Science and Engineering, School of Materials andChemical Technology, Tokyo Institute of Technology, Japan*ashishid@res.titech.ac.jp

Photocontrol of surface topology is key to developing highly functional materials and devices in
the field of optics, mechanics, and electronics. Although many researchers have reported photoinduced
surface structures [1], it is still challenging to induce surface structures without complicated processes
using photoresponsive dye molecules and polarized light. Recently, we revealed that a surface relief
structure was formed in the polymer film by patterned photopolymerization, based on a concept ofmolecular diffusion [2]. Here, we investigated the detailed relationship between the surface relief
structure and molecular alignment induced by the molecular diffusion.
A mixture composed of an anisotropic monomer, a crosslinker, and a photoinitiator was prepared
as a photopolymerizable sample. The solid-state sample mixture was melted above its isotropic
temperature (150 °C) on a hot stage, injected into a glass cell(thickness, 2-3 µm), and cooled down to the photopolymerization
temperature of 100 °C. The photopolymerization was conductedusing patterned UV light with bright and dark stripes (Fig. 1). The
confocal laser micrographs showed formation of surface relief
structures in the obtained film. Polarized optical microscopy
revealed thatbirefringence was highest at the boundaries

between bright and dark areas. According to the comparison of
the degree of the molecular alignment with the surface relief

Fig. 1 Schematic of patternedphotopolymerization

structure, the shape and height of the formed structures were affected by molecular motion induced bypatterned photopolymerization [3].

References[1] T. Seki, Bull. Chem. Soc. Jpn. 91 (2018) 1026.
[2] K. Hisano, A. Shishido, et al., Appl. Phys. Express 9 (2016) 072601.
[3] S. Hashimoto, A. Shishido, et al., Liq. Cryst. 46 (2019) 1995.

O7

Soft Elasticity Effects in Nematic Elastomers Revealed by
Various Types of Deformation
Suzuka Okamoto, Asaka Takebe, Haruki Tokumoto, Takuho Naraoka andKenji Urayama*

Department of Macromolecular Science and Engineering, Kyoto Institute ofTechnology, Japan* urayama@kit.ac.jp

Ideal nematic elastomers (NEs) are theoretically expected to exhibit a liquid-like behavior
with zero shear modulus due to the coupling of nematic director and rubber elasticity, which is termed“soft elasticity”.[1] Many real NEs have finite shear modulus, but they show a low plateau stress overfinite strain range when stretched normal to the initial director, or when polydomains are uniaxially
stretched,[2] both of which have been regarded as the indication of soft elasticity effect. Most of theearlier studies have investigated the mechanical behavior of the NEs exclusively by uniaxial stretchingnormal to the initial director. However, the characterization using uniaxial stretching provides a limited
basis to understand the large deformation behavior of NEs, because it is only a particular one among allaccessible deformations. We characterize the large deformation behaviors of NEs using various typesof deformation including uniaxial stretching at oblique angles relative to the initial director, biaxial
stretching and torsion.
Figure 1 shows the nominal stress –stretch relations of a monodomain NE with planaralignment in uniaxial stretching at various
stretching angles (q0). The q0 is the angle between
the uniaxial stretching and initial director. The
stress-plateau width (lE) increases with q0 whereas
the plateau vanishes at q0 < 24o. The q0 dependenceof lE is successfully explained by a scenario of theFig. 1. Uniaxial nominal stress versus stretch for amonodomain NE with planar alignment at various
soft elasticity theory, i.e., a planar stretching via
stretchangles.
director rotation.[3]In biaxial stretching of polydomain NEs,
we observe that the two orthogonal true stresses are equalized independent of strain biaxiality.[4] This
unusual feature means that the polydomain NE sheet undergoes the shape change at no extra energy
cost under the constant true biaxial stress conditions, indicating a liquid-like behavior. We also
observe a pronounced effect of soft elasticity in a polydomain NE cylinder under torsion.
References[1] M. Warner, E. M. Terentjev, Liquid Crystal Elastomers, Oxford, 2003.
[2] A. Takebe and K. Urayama, Phys. Rev. E (2020).
[3] S. Okamoto, S. Sakurai, K. Urayama, Soft Matter (2021).
[4] H. Tokumoto, H. Zhao, A. Takebe, K. Kamitani, K. Kojio, A. Tsukahara, K. Bhattacharya, K. Urayama,
under review.

O8

Marangoni convection driven by temperature gradient near an
isotropic-nematic transition pointJun Yoshioka* and Koji Fukao

Department of Physical Science, Ritsumeikan University, Japan* j-yoshi@fc.ritsumei.ac.jp

When temperature or concentration field is not uniform in a fluid surface, a surface tension gradientis generated. This often results in the formation of a convective flow, which is called Marangoni
convection. In the convection due to the non-uniformity of the temperature field, the flow from high to
low temperature region has been typically observed in liquid surfaces, because the surface tension
increases with the decrease of the temperature in typical liquids. This tendency, however, is notnecessarily observed in the liquid crystalline (LC) materials, and especially in the temperature nearisotropic (I)-nematic (N) transition point, a singular behavior with a drastic decrease and increase of
the surface tension has been reported [1]. Hence, we considered that the flow from high to
low-temperature region would not be always driven in the surface of LC. To clarify this, in this study
we observed the Marangoni flow in the N LC material of 7CB under the temperature gradient. The
gradient was applied by the experimental system illustrated in Fig.1, and the flow field near the airinterface was analyzed by fluorescence photo-bleaching method as shown in Fig.2. In the N phase, theflow away from the interface was observed in low-temperature side,and the flow toward the interface in high-temperature side. This flow

Cooling

Copper(Cu) foil
Observation
area
Side view
Cover glass

interface. On the other hand, in the I and the coexistence state of the I
and N phases, the flow direction was opposite from that in the N phase.
This difference in the flow direction is resulted from the singularity ofSampleCu foilCover glass

the temperature dependence of the surface tension near the I-N
tension gradient and the flow will be reported in presentation.
Cu
foil

Cu
foil

N

I+N

Heating

Sampledistribution indicates the existence of the convection near the airtransition point. The detail about the relation between the surface

Top view

Fig.1 Schematics
experimental setup.

I

Air interface
CoolingHeating(a)(b)(c)
Fig.2 Measurement results of flow field by photo-bleaching method. The field is indicated byaqua arrows, and the temperature gradient was set to be 35K/mm. The dye of C6-NBD
Ceramide was added for the fluorescence observation. (a) N phase (Averaged temperaturein the sample T0 is 36°C). (b) I-N coexistence phase (T0=42°C). (c) I phase (T0=47°C).

References [1] T. Tintal, R. Moldovan, T. Beica and S. Frunza, Liq. Cryst. 28 (2001) 793

of

O9

Development of novel spectroscopy systems to directly observe
microscopic translational molecular dynamics in various liquid
crystal phases
Makina Saito1*, Jun Yamamoto2, Yoda Yoshitaka3, Makoto Seto4
1 Department of Physics, Tohoku University, Japan
2 Department of Physics, Kyoto University, Japan
3 Japan Synchrotron Radiation Research Institute, Japan
4 Institute for Integrated Radiation and Nuclear Science, Kyoto
University, Japan*makina.saito.d6@tohoku.ac.jp

Unique properties and functionalities of liquid crystal phases originate from the coexistence of
microscopic molecular orders and molecular mobility. Understanding the microscopic molecular
dynamics in association with the order is highly important to microscopically elucidate the macroscopic
functionalities.

Recently, wedeveloped synchrotron-radiation-based

quasi-elastic

scattering

spectroscopy using multi-line time-domain interferometry (TDI) of Mössbauer gamma rays [1]. The
multi-line TDI system allows us to determine the intermediate scattering function in the angstrom andnanometric spatial scales and in time scales between few nanoseconds and sub-microsecond, in whichmolecular translational motions occur in many liquid crystal phases [1]. So far, molecular dynamics innematic, cholesteric, smectic A, and cholesteric blue phases has been measured [2-4]. In thispresentation, we introduce new application results on molecular translational dynamics studies for
smectic B and smectic C phases. In both cases, we could selectively determine the time scales of the
microscopic molecular translational motions across the smectic layer and inside of the layer, respectively.
It was revealed that the molecular dynamic behaviour in smectic B phase is apparently different fromthese in smectic A and C phases due to the creation of the bond-orientational order in smectic B phase.
In this presentation, we also introduce another new synchrotron-radiation-based spectroscopy
system using nuclear Bragg monochromator. Recently, it was demonstrated that the new system allows
for the determination of molecular dynamics between 100 picoseconds and 10 nanoseconds. It is
expected that the molecular dynamics can be measured in most of liquid crystal phases and hightemperature isotropic phases by combination of the two spectroscopy systems. We discuss the possible
applications of these new dynamics measurement systems on liquid crystal phases. This work was
supported by JST CREST Grant Number JPMJCR2095, Japan.
References[1] M. Saito, R. Masuda, Y. Yoda, M. Seto, Sci. Rep. 7, 12558 (2017).
[2] Makina Saito, Makoto Seto, Shinji Kitao, Yasuhiro Kobayashi, Masayuki Kurokuzu, Jun Yamamoto,and Yoshitaka Yoda, J. Phys. Soc. Jpn. 81, 023001 (2012).
[3] Makina Saito, Jun Yamamoto, Ryo Masuda, Masayuki Kurokuzu, Yoshitaka Yoda, and Makoto
Seto, Hyperfine Interact. 241, 14 (2020).
[4] Makina Saito, Jun Yamamoto, Ryo Masuda, Masayuki Kurokuzu, Yohei Onodera, Yoshitaka Yoda,
and Makoto Seto, Phys. Rev. Res. 1, 012008(R) (2019).

O10

A simple molecular model showing ferroelectric nematic orderTakeaki Araki1, and Sayane Hattori1

1 Department of Physics, Kyoto University, Japan* araki.takeaki.5a@kyoto-u.ac.jp

Ferroelectric liquid crystals are partially ordered anisotropic fluids with ferroelectricity. Althoughferroelectric nematic phase composed of rod-like molecules with electric dipole was predicted
theoretically, its experimental realization has not been reported for a long time. Recently, someexperimental groups have succeeded in synthesizing molecules which possibly show ferroelectric
nematic order [1-2].
In this work, we numerically study ferroelectric nematic phase formation with a simple molecularmodel. A conventional nematic phase does not have polar order even if the rod-like molecules have theelectric dipoles along their long axes. It is considered that a pair of the rod-like molecules are placedside-by-side and oriented toward the opposite directions because of the dipole-dipole interaction. This
local alignment cancels the polar order.
We employ rod-like molecules with a bulky central part. We expect that the side-by-side alignment isavoided by the bulky central part and the polar order is not canceled. Each molecule is given as an arrayof the Lennard-Jones particles. It is known that the system exhibits isotropic-nematic-smectic transitions
by changing the temperature and/or the packing fraction when the molecule is long enough. In our model,
the molecules are composed of eight particles, and the central two particles are enlarged by the ratio 𝜃𝜃.
Each rod-like molecule has an electric dipole along its long axis at the center by introducing the positive

and negative electric charges to the central two particles. We carry out molecular dynamics simulation
under the 𝑁𝑁𝑁𝑁𝑁𝑁 ensemble. Although spontaneous orderings have not been observed, our molecularsystems possibly show ferroelectric nematic order by employing aligned initial conditions. Figure 1
shows the dependences of the nematic order

𝑃𝑃2 and the polar order 𝑃𝑃1 against thepacking fraction 𝜌𝜌. The particle size ratio
is changed from 𝜃𝜃 = 1.0 to 𝜃𝜃 = 1.5. In

the system of 𝜃𝜃 = 1.5, we observed theferroelectric order (𝑃𝑃2 > 0, 𝑃𝑃1 > 0) when

the packing fraction is large. This work was
supported by JST, CREST Grant Number
JPMJCR2095, Japan.

Fig. 1 Dependences of the (a) nematic 𝑃𝑃2 and (b)polar order 𝑃𝑃1 on the packing fraction 𝜌𝜌 . The
particle size ration 𝜃𝜃 is changed.

References[1] X. Chen et al., Proc. Natl. Acad. Sci. U.S.A, 117, 14021 (2020).
[2] H. Nishikawa et al., Adv. Mater. 29, 1702354 (2017).

O11

Controlling the temperature range of ferroelectric nematic
phases based on eutectic phenomenon
Hirotsugu Kikuchi1*, Yuta Mizuki2, Yasushi Okumura1, Shizuka Anan1

1 Institute for Materials Chemistry and Engineering, Kyushu University, Japan
2 Interdisciplinary Graduate School of Engineering Sciences, Kyushu University,Japan* kikuchi@cm.kyushu-u.ac.jp

A fluorinated liquid crystal with 1,3-dioxane skeleton(C3DIO) exhibits ferroelectricity and abnormallylarge dielectric constants reaching 10,000 in the
ferroelectric nematic phase (NF phase which used to becalled MP phase)[1]. However, the NF phase of

Figure 1 Chemical structure of CnDIO.

C3DIO is mainly a monotropic phase which appears during the cooling process and is therefore
thermodynamically metastable, while the temperature range of the thermodynamically stableenantiotropic NF phase is very limited. Therefore, an enlargement of the temperature range of thethermodynamically stable NF phase is strongly desired. Here, we present an enlargement of athermodynamically stable temperature range of NF phase by freezing point depression using eutectic
phenomenon appeared through mixing a series of fluorinated liquid crystals (CnDIO (n = 1, 2, 3, 4), Fig.
1) with different alkyl chain length.
Dielectric properties of C2DIO/C3DIO and C1DIO/C4DIO mixtures with different mixing ratios were
measured in homeotropic alignment ITO glass cells at different temperatures in heating processes.
Temperature dependences of dielectric constants

16000

in C1DIO/C4DIO mixture with different mixture
coexisting phases showing a relative dielectric

70/30

regarded as an NF phase. In the C2DIO/C3DIO

0

extended to 17 °C. For the C1DIO/C4DIO
mixture, melting point of C1DIO/C4DIO=20/80

60/40
50/50
40/60

4000

C2DIO/C3DIO=70/30 wt. ratio mixture was

80/20

8000

constant of 1,000 or more at 100 Hz were
mixture, a temperature range of NF phase of

90/10

12000

!(∥) $

ratio are shown in Fig.2. Liquid crystal phases or

C1DIO/
C4DIO

30/70
20/80
10/90

30

50

70

90

110 130 150

Temperature / °C

Figure 2 Temperature dependences ofdielectric constants in C1DIO/C4DIO mixture
with different wt. ratio.

wt. ratio mixture was reduced by 21 °C from that of pure C4DIO, and the temperature range of the NF
phase was extended to 20 °C.
References[1] H. Nishikawa, K. Shiroshita, H. Higuchi, Y. Okumura, Y. Haseba, S. Yamamoto, K. Sago, and H. Kikuchi,
Adv. Mater., 29(2017)1702354.

O12

Development of weak anchoring surface for nematic liquid
crystal reorientation modified with silane coupling reagents
Shizuka Anan,1 Yu Fukunaga,2 Koji Fujikawa,2 Yasushi Okumura1 and
Hirotsugu Kikuchi1*

1. Institute of Material Chemistry and Engineering, Kyushu University, Japan
2. Interdisciplinary Graduate School of Engineering Sciences, Kyushu University,Japan* kikuchi@cm.kyushu-u.ac.jp
Introduction
With the development of communication devices, the number of personal smartphones and PC
devices with liquid crystal (LC) displays is rapidly increasing, thus decreasing of the power consumptionof LC displays is crucially demanded. In general, the LC contacting with the substrate surface is strongly
anchored to the surface, resulting inhibition of reorientation of LC by electric field, therefore, thedevelopment of weak anchoring cells is a promising way to decrease power consumption. In the present
work, we performed weak anchoring of LC and glass substrate by modification of silane coupling
reagents and examined the effect of chemical structure of silane coupling reagents.
Experiments
Ethyltrimethoxysilane (C2) and 3-Glycidyloxypropyltrimethoxysilane (GTMS) were used forsurface modification of glass substrates. Silane coupling reagents and water were dissolved in ethanol
with pH controlled by acetic acid or hydrochloric acid. The solution was stirred at room temperature for
12 hours to hydrolyze the methoxy groups of silene coupling reagents, followed by stirring at 130 °C
for 5 hours for polymerization. The resulting liquid was diluted by cyclopentanone, and glass substrates
were spin coated with the solution at 3,000 rpm. After the coating, the substrates were heated under
reduced pressure at 130 °C for 1 hour. A mixture of liquid crystal (JC1041XX: 5OCB = 1: 1 (w/w)) was
filled in a 10-μm thick cell composed of the modified glass substrates. The anchoring effect were
evaluated by polarizing optical microscopic (POM) observation under magnetic field with azimuth
rotation.
Results and Discussion
From POM observation, the LC in both silane coupling modified and unmodified cell showedplanar orientation at a temperature range of nematic phase. The director of LC in C2 modified cellrotated accordingly with the rotation of magnetic field, while no change was observed in unmodified
glass cell. Furthermore, we observed LC in the cell modified with C2 hydrolysis rate of 30% (C2-30)
and 100% (C2-100) at the first step of synthesis to compare the effect of chemical structures. The
samples of C2-30 and C2-100 highly and poorly responded to the magnetic field, respectively,
indicating that the remaining C-O bonds reduced the anchoring strength. LC cells were also synthesizedfrom GTMS with C-O bond at side chain to see the effect of C-O bonds for anchoring. This GTMS
modified cell showed weaker anchoring than the C2 modified cell, supporting that the silane coupling
reagents with C-O bonds is responsible for reducing the anchoring strength between LC and glass
substrate.
Acknowledgment This work was supported by JST-CREST Grant Number JPMJCR1424 and JSPS
Grant Number 18H03920.

O13

Superior electro-optical response in Organic molecules
doped in the nematic liquid crystal device: present status
and future perspectives.
Pravinraj Selvaraj1, Mareena Antony1, Che-Ju Hsu2*, Chi-Yen Huang2*
1

Department of Physics, National Changhua University of Education, Changhua
500, Taiwan.
2
Graduate Institute of Photonics, National Changhua University of Education,
Changhua 500, Taiwan.
* Correspondence to windtrace428@gmail.com and chiyen@cc.ncue.edu.tw.

Abstract: A superior electro-optical response has been achieved by doping organic
N-benzyl-2-methyl-4-nitroaniline (BNA) and Morpholinium 2-chloro-4-nitrobenzoate (M2C4N) innematic liquid crystals (LCs) reported in this study. The BNA and M2C4N-doped LC cells have afive-fold fall time (τoff) and threefold faster than the pristine LC cell, respectively. The possible reason
behind the τoff could be the remarkable decrements in the rotational viscosity and threshold voltage by
45% and 27%, respectively, and a strong additional restoring force resulted from the spontaneouspolarization electric field BNA. Contrastingly, the dielectric anisotropy (Δε) of the LC mixture
increases by 17% and 7%, respectively, with M2C4N and BNA dopants. M2C4N dopant induces atremendous dielectric anisotropy because the phenyl-amine/hydroxyl in M2C4N induces a robustintermolecular interaction with LCs. Additionally, BNA dopant roots a strong absorbance near the
wavelength of 400 nm that filters the blue light. Density Functional Theory(DFT) calculations explain
the results mentioned above and confirm that BNA and M2C4N increase the dipole moment,
polarization anisotropy, and hence Δε of LC mixture. These results indicate that M2C4N doping can beused to develop a high Δε of LC mixture, and BNA doping is suitable to fabricate a fast response andpotentially anti-ultraviolet (UV) applications, such as anti-UV smart windows, glasses, and promising
application fields of LC devices and displays.
Keywords: Organic molecule; liquid crystal; fast response time; density functional theory(DFT).

Fig.1. (a) τoff, (b) Δε as functions of BNA and M2C4N-doped LC cells at 1 kHz, respectively,(c & d) Theoretical absorption spectra and optimized geometries for 5CB, BNA, M2C4N, 5CB + BNA, and
5CB + M2C4N by Density Functional Theory (DFT).
Reference:[1]
Huang, C.Y, Opt. Express, 28, 10572-10582, (2020).

O14

Large aperture liquid crystal lens using the hybridalignment layer with titanium dioxide nanoparticle andpolyimide composite
Mareena Antony1, Pravinraj Selvaraj1, Che-Ju Hsu2*, and Chi-Yen
Huang2*
1

2

Department of Physics, National Changhua University of Education, Changhua
500, Taiwan

Graduate Institute of Photonics, National Changhua University of Education, Changhua 500, Taiwan.

* mareenaros@gmail.com

ABSTRACTThe hole-patterned LC lens is an attractive option because it possesses excellent tunable focal length
capability, realizes any sizes of optical aperture easily and only requires simple fabrication andaddressing scheme [1]. The hole-patterned liquid crystal (LC) lens has been fabricated using the hybridalignment layer with the rutile titanium dioxide (TiO2) nanoparticles (NPs)- coated polyimide (PI).
Electro-optical properties of the pure PI and hybrid PI- LC lenses such as the TiO2 NPs–doped
concentration of the hybrid alignment was set to 0.1, 0.5 and 1.0 wt% are demonstrated and compared. Theinterference fringes and focal lengths of the fabricated LC lenses are measured to compare the operation
voltage and lens power. The wavefront error and the full width at half maximum (FWHM) of the
focusing spot of the LC lens are determined to analyze the lens and focusing qualities. The responsetime of the LC lens is determined by a transient transmission measurement. The imaging performanceof the LC lens is recorded.
The experimental results introduce the utilization of the hybrid PI-layer decreases the turn-off timeof the LC lens by ~2x, due to the increased interaction between the LCs and alignment layer. The
appropriate TiO2 NP-doped concentration also decreases the turn-on time of the LC lens by ~4x incomparison with the pure PI-LC lens. Notably, it does not degrade the focusing and lens qualities.
However, the hybrid alignment layer decreases the lens power and increases the operating voltage of thelens, possibly due to the rough PI surfaces from TiO2 NPs aggregation and the increased screen effect.
The imaging performance of the hybrid PI-LC lens has been demonstrated practically through focusing
on three objectives at different distances. While varying the applied voltage, the lens cell has functionedon three objects at different positions with tunable focusing.

Fig. 1. Schematic of the hole-patterned LC lens structure.

References[1] Liquid crystal lens with doping of rutile titanium
dioxide nanoparticles Che Ju Hsu1, Bhupendra Pratap Singh2, Mareena Antony3, Pravinraj Selvaraj4, Rajiv
Manohar2 and Chi Yen Huang1*, Optics Express 22856 Vol. 28, No. 15, 20 July (2020).

O15

Bragg diffraction of light at oblique helicoidal cholestericstructures
Olena S. Iadlovska12*, Kamal Thapa12, Mateusz A. Mrukiewicz13, Georg
H. Mehl4, Christopher Welch4, Daniel A. Paterson5, Ewan Cruickshank5,
Grant Strachan5, Corrie T. Imrie5, Sergij V. Shiyanovskii1, and Oleg D.
Lavrentovich12

Advanced Materials and Liquid Crystal Institute, and 2Department of Physics,
Kent State University, Kent, OH 44242, USA; 3Institute of Applied Physics, Military University ofTechnology, 00-908 Warsaw, Poland; 4Department of Chemistry, University of Hull, Hull HU6 7RX,
UK; 5Department of Chemistry, School of Natural and Computing Sciences, University of Aberdeen,
AB24 3UE Scotland, UK
1*oiadlovs@kent.edu

Chiral mixtures with a small bend elastic constant exhibit a peculiar oblique helicoidal
cholesteric (ChOH) state when acted upon by an electric field [1-2]. Both the period P and thecone angle θ of the ChOH are tunable by the applied field in a broad spectral range. The ChOH
state forms in chiral mixtures composed of flexible dimers which exhibit bent molecularconformations (see, e.g. [3]). At the normal incidence of light, reflection from the ChOH
half-pitch P/2 is used for the first in-situ measurements of bend elastic modulus of the chiralmaterial [4]. At the oblique incidence of light, reflection from two periodicities associatedwith the full P and the half-pitch P/2 is tunable by the electric field and the angle of incidence.
The full and the half-pitch bandgaps have distinct polarization characteristics, Fig.2. The work
is supported by the NSF grant ECCS-1906104.

Fig. 1. Oblique helicoidal cholesteric structure with thepitch P and the cone angle θ tunable by applied electricfield E. At the oblique incidence of light, two
periodicities associated with the full P and thehalf-pitch P/2 are observed in reflection. Notation forangles: β is the angle of incidence, θ is the cone angle.

Fig. 2. Polarization characteristics ofreflection from (a) the full P and (b)the half-pitch P/2 in the planar ChOH
cell, d = 23 µm, at the angle ofincidence of polarized light β = 45°.

References[1] J. Xiang et al, PRL 112(21), 217801 (2014).
[2] J. Xiang et al, Advanced Materials 27, 3014 (2015).
[3] G. Babakhanova, Z. Parsouzi, et al, PRE 96, 062704 (2017).
[4] O. Iadlovska et al, PRResearch 2, 013248 (2020).

O16

The Two-dimension Diffraction and the Milky Haze of a Largescale Topological Defect Array in Nematic Liquid Crystal
Ya-Zi Wang, Jieh-Wen Tsung*Department of Electrophysics , National Chiao-Tung University,
Hsinchu, Taiwan
Presenter:Ya-Zi Wang, email:yatsi841203.ep08g@nctu.edu.tw

Abstract: Large array of topological defects in nematic liquid crystal (NLC) canbe applied as smart windows. The haze is a mixture of three optical effects, diffraction, scattering oflight, and lensing effects. The diffraction and lensing effects are significant when the defects are
periodically arranged. Sometimes the sharp glitter due to the diffraction and the split multiple image due
to lensing may lead to uncomfortable visual experiences. The scatter generates the soft, milky feature
which is friendly to the viewer. Therefore, in this research, large, dense, messy topological defectnetwork is generated in NLC test cell. The director field and diffraction pattern are analyzed carefully.
We developed new experiment and analysis methods to distinguish the glitter of diffraction and milky
texture of scattering. Our new device may lead to smart windows with better visual experiences. In
addition, topological defect arrays have innovative applications, such as optical vortex generation andphase gratings. It can be used for dynamic beam steering, which is essential for holography [1].

(a)

(b)

Figure 1: NLC operated by vertically aligned mode (a)The test cell structure. (b)Each pad pixel has one
defect which topological charge of +1 at the center and one hyperbolic hedgehog with topological charge of-1 between the pads

(a)

(b)

(c)

(d)

Figure 2: (a) test cell test cell lay on the picture with applied voltage (b) the test cell lifted (c) the visual
blur caused by different pixel size (d) POM image of the test cell
(i)

(j)

(k)

(l)

Figure 3: optical and visual effect vs. pixel size(a-h) and lattice structure (i-l) with annulus shaped electrode. (a-d)50 m pixel; (e-h) 20 m pixel; (i)(j)square lattice; (k)(l) hexagonal lattice. (a)(e) test cell without voltage (b)(f)(i)(k) test cell with 16 V (c)(g)diffraction pattern (d)(h)(j)(l) POM image of AC voltage applied.
References[1] MinSu Kim and Francesca Serra, “Tunable Dynamic Topological Defect Pattern Formation in Nematic Liquid Crystals”,
Adv. Optical Mater. 2020, 8, 1900991 (2019)

O17

Preferred Photo-Induction of
ANBC-22/Azo Binary Mixture

Ia3d

Cubic

Phase

in

Shoichi Kutsumizu1*, Tomonori Kondo1, Masamichi Ogawa1, Yuka
Mizutani1, Yohei Miwa1, Yasuhisa Yamamura2, and Kazuya Saito2

1 Department of Chemistry and Biomolecular Science, Faculty of Engineering,
Gifu University, Japan
2 Department of Chemistry, Faculty of Pure and Applied Sciences, Universityof Tsukuba, Japan* kutsu@gifu-u.ac.jp
Thermotropic bicontinuous cubic (Cub) and smectic C (SmC)
liquid crystalline (LC) phases form three-dimensionally (3D)and one-dimensionally (1D)- organized packing structures,
respectively. LC states often change their organizations in
response to various external stimuli such as temperature, UV
light, and so on. One of our main interests is to control thetransformation from 1D SmC to 3D Cub structures using lightbecause such transformations accompany dramatic changes in
optical and mechanical properties [1,2].

Fig. 1 Packing structures of two
Cub phases, where molecular coreregions are painted in blue. In (a),helical arrangement of anti-spindlelike molecules is also illustrated.

The gyroid-type

Ia3d structure (Fig. 1a) is a famous Cub organization seen
in a wide range of materials. In this organization
composedof

seemingly

rod-likebutactually

anti-spindle-like molecules, packing frustration of suchmoleculesisessential

for

the

controlofthetransformation.
The system examined in this study comprises twocomponents, an Ia3d Cub LC molecule (here denoted
ANBC-22, the upper part of Fig. 2) and an azobenzene
molecule of a similar structure (Azo, Fig. 2). The system

Fig. 2 (Upper) Chemical structures of
two components constructing the binary
mixture examined. (Lower) Transition
schemes of mixtures containing threedifferent Azo amounts.

exhibits a SmC phase for all Azo amounts, and just above the phase,an Ia3d phase is formed at 19 mol% Azo while an ‘Im3m’-like chiral
cubic phase (Fig. 1b) appears at 9 and 15 mol% (see the lower part in Fig.
2). UV-irradiation of the SmC phase of these three mixtures induced the
Ia3d cubic phase (Fig. 3 for 15 mol%). Since the trans-cis photoisomerization of Azo molecules increases the system’s entropy, theFig. 3 Photo-induction of
Ia3d phase as seen from
9 and 15 mol% of the Azo, the induced phase is not the actual X-ray diffraction for 15
high-temperature phase. The mechanism will be proposed and discussed. mol% Azo mixture at 369 K(q= q; q, scattering vector).
Referencestransitions seem to mimic being heated. What to note here is, however, at[1] R. Hori et al., Chem. Eur. J., 18 (2012) 7346; [2] A. Nagai et al. Bull. Chem. Soc. Jpn., 91 (2018) 1652.

O18

Immobilization, Reorientation and Migration of Cholesteric
Shells for Photonic Applications
Yoshiaki Uchida1*

1 Graduate School of Engineering Science, Osaka University, Japan* yuchida@cheng.es.osaka-u.ac.jp

Cholesteric phases have one-dimensional helical structures. A cholesteric layer between two parallelinterfaces with tangential molecular alignment affects visible lights propagating parallel to the layer
normal. When the helical pitch is comparable to the light wavelength, the light with the same helicity
as the cholesteric helical structure is fully reflected. The cholesteric phase is easily curved; e.g., acholesteric shell between two tangentially aligning interfaces can work as three-dimensional chiralphotonic crystals [1]. Microfluidic devices enable us to fabricate mono-dispersed droplets and coreshell emulsions. We have developed microfluidic techniques to fabricate and manipulate capsules withhigh-melting-point and/or high-viscosity materials [2]. Cholesteric shells with a dye in the inner phaseexhibit omnidirectional laser action [1,3]. Besides, cholesteric shells with luminol in the inner phasework as chemiluminescence sensors for hydrogen peroxide [4].
Here we present the techniques and materials for the
manipulation of cholesteric shells. First, we developed thesynthesis method of ordered porous film to immobilizecholesteric shells, as shown in Fig. 1 [5]. We found that a
topologically essential defect in the cholesteric shell leads tothe self-assembly of particles dispersed in the shell. It can
induce “mutualistic self-assembly” in the cholesteric shell with

Fig. 1 Photograph of cholestericshells immobilized in porous film.

magnetic nanoparticles [6]. We focused on magnetically controllable droplets of liquid crystalline
nitroxide radicals (LC-NRs) even without any metal elements [7,8]. We succeeded in the synthesis ofa new low-melting-point LC-NR showing a cholesteric phase. Owing to the temperature dependenceof selective reflection that the cholesteric phase shows, the cholesteric shells with the new LC-NR
work as magnetically migratable temperature sensors.
References[1] Y. Uchida, Y. Takanishi and J. Yamamoto, Adv. Mater. 25 (2013) 3234.
[2] T. Akita, H. Kouno, Y. Iwai, Y. Uchida and N. Nishiyama, J. Mater. Chem. C 5 (2017) 1303.
[3] Y. Iwai, R. Iijima, K. Yamamoto, T. Akita, Y. Uchida and N. Nishiyama, Adv. Opt. Mater. 8 (2020)
1901363.
[4] Y. Iwai, H. Kaji, Y. Uchida and N. Nishiyama, J. Mater. Chem. C 2 (2014) 4904.
[5] Y. Iwai, Y. Uchida, H. Yabu and N. Nishiyama, Macromol. Rapid Commun. 38 (2017) 1600502.
[6] Y. Iwai, Y. Uchida and N. Nishiyama, Adv. Opt. Mater. 4 (2016) 1961.
[7] Y. Uchida, N. Ikuma, R. Tamura, S. Shimono, Y. Noda, J. Yamauchi, Y. Aoki and H. Nohira, J. Mater.
Chem. 18 (2008) 2950.
[8] Y. Uchida, K. Suzuki, R. Tamura, N. Ikuma, S. Shimono, Y. Noda and J. Yamauchi, J. Am. Chem. Soc.,
132 (2010) 9746.

O19

Quantification of internal strain in bent silicone elastomers via
selective reflection of cholesteric liquid crystals
Masayuki Kishino1,2, Norihisa Akamatsu1,2, Ryo Taguchi1,2, Shoichi
Kubo1,2, Kyohei Hisano3, Osamu Tsutsumi3, Atsushi Shishido1,2*

1 Laboratory for Chemistry and Life Science, Institute of Innovative Research,
Tokyo Institute of Technology, Japan
2 Department of Chemical Science and Engineering, School of Materials andChemical Technology, Tokyo Institute of Technology, Japan
3 Department of Applied Chemistry, Graduate School of Ritsumeikan
University, Japan*ashishid@res.titech.ac.jp

Flexible devices composed of soft materials, such as polymers, elastomers, and liquid crystals haveattracted a lot of interest as a next-generation device. An obstacle for developing flexible devices isdeterioration of their performance during bending. Enhancing bending durability of devices requires
appropriate design based on bending behavior of soft material components. Although many researches
have reported on the bending behavior of soft materials [1-3], internal strain in bending soft materials
has not been measured due to experimental constraints. Measuring internal strain is essential tounderstand the bending behavior, leading to optimized device design.
To measure internal strain in bending soft materials, we focus on
selective reflection of a cholesteric liquid crystal (CLC). The selective
reflection arises from a self-organized helical structure of CLC, according
to λ = nP (where λ, n, and P represent reflection wavelength, refractive
index, and helical pitch, respectively). Mechanical strain changes thehelical pitch (P) and reflection wavelength (λ) [4], thus internal strain
induced by bending of soft materials can be evaluated via reflection
wavelength change of CLC. In previous work, we fabricated a CLC
sensor that can detect internal strain in soft materials [5]. Herein, using
the CLC sensor, we quantified internal strain in a bending
polydimethylsiloxane (PDMS) film which is a common soft material(Fig. 1). As a result, internal strains in the bending PDMS film were

Fig. 1 Measurement ofinternal strain in a PDMS
film via selective
reflection of CLC.

asymmetric: 19% compression and 17% tension occurred in bending outer and inner surfaces,
respectively. Surprisingly, large bending of the PDMS film caused 7% compression in the middle ofthe film thickness where strain was assumed to be zero. This work will help us design flexible devices
with high bending durability.
References[1] N. Akamatsu, A. Shishido, et al., Sci. Rep. 4 (2014) 5377.
[2] K. Kuwahara, N. Akamatsu, A. Shishido, et al., Appl. Phys. Express 13 (2020) 056502.
[3] R. Taguchi, N. Akamatsu, J. Takeya, A. Shishido, et al., Adv. Mater. Interfaces 8 (2021) 2001662.
[4] M. Kishino, N. Akamatsu, A. Shishido, et al., J. Appl. Phys. in press.
[5] M. Kishino, N. Akamatsu, A. Shishido, et al., J. Photopolym. Sci. Technol. 33 (2020) 81.

O20

Polarized microscopy of domain textures of nematic
elastomers
Takuya Ohzono1 and Kaoru Katoh2

1 Research Institute for Advanced Electronics and Photonics, AIST, Japan
2 Biomedical Research Institute, AIST, Japanohzono-takuya@aist.go.jp

Liquid crystal elastomers, LCE [1], are weakly crosslinked polymer networks with molecular units
often called “mesogens” that induce liquid crystal, LC, phases. In the case of nematic LCE, theattractive interaction between mesogens tend to align their long molecular axes along each other.
Since the network is crosslinked, the molecular units are not mobile as in the low molecular weight,
Mw, nematic LC. Instead, the nematic tensor order parameter couples to the strain field via thepolymer network, leading to novel actuation and morphing applications.
Here, we present polarized microscopy study of domain textures of nematic LCE. A polydomain
texture is known to spontaneously form upon cooling from the isotropic state, at which thepolymerization has proceeded. Unlike the schlieren texture on low Mw nematic LC, the nematic
domains cannot coarsen due to the frozen network topology by chemical crosslinks. As a result, thenematic domains with a characteristic length typically of ~1 micrometer are stabilized, showing
opaque appearance macroscopically due tothe multiple scattering from the birefringent
domains. It is revealed via polarized
fluorescencemicroscopy

that

the

characteristic domain texture with specificorientationalcorrelationofnematic

directors exists (Fig). This qualitative
feature has been theoretically expected by

Fig. Polarized confocal fluorescence microscopy

Uchida [2] and experimentally revealed

image of polydomain nematic LCE (7.62 um2).

here for the first time. This observation

Domains with n parallel to polarizers (P,A) appear

method can be useful for characterizations

bright according to the dichroism of probe dyes.

of domain transformation under strain andNote the characteristic orientational correlation in

upon nematic-isotropic phase transition±45º to n and domain size of ξav ~1 μm.

[3,4].
References[1] E. M. Warner, M., Terentjev, Liquid Crystal Elastomers, Oxford Univ. Press, 2007.
[2] N. Uchida, Phys. Rev. E 2000, 62, 5119.
[3] T. Ohzono, K. Katoh, H. Minamikawa, M. O. Saed, E. M. Terentjev, Nat. Commun. 2021, 12, 787.
[4] T. Ohzono, K. Katoh, E. M. Terentjev, Macromolecules 2021, 54, DOI:10.1021/acs.macromol.1c00356
Acknowledgements: This work was partly supported by JSPS KAKENHI Grant Number 20K20967. The
authors are grateful for many useful communications from E. M. Terentjev and M. O. Saed.

O21

Super-Monodispersed Cholesteric-Liquid-Crystal Polymer
Microparticles
with
Three-DimensionallyControlled
Molecular Orientation
Tomoki Shigeyama1, Kyohei Hisano1, and Osamu Tsutsumi1*

1 Department of Applied Chemistry, Ritsumeikan University, Japan* tsutsumi@sk.ritsumei.ac.jp

Insphericallyconfinedliquidcrystalsystems,

molecularalignment

canbethree-dimensionally controlled by surface anchoring. Thus, the liquid crystal microparticles exhibit
unique optical properties depending on molecular alignments. In particular, cholesteric-liquid-crystal(Cho-LC) microparticles have drawn attention because of their three-dimensionally controlled helicalalignment of mesogens and their optical properties based on the helical alignment. In this work, wedeveloped monodispersed polymer particles composed by the Cho-LC with precisely controlled
helical axis orientation. We report that such monodispersed polymer microparticles can be easily
prepared by the conventional dispersion polymerization. In the polymerization process, monodomain
of Cho-LC was spontaneously formed in the polymer particles. To date, the mechanism for the LCalignment in the polymer particles during dispersion polymerization has been still unclear. Here, wefirst report the detailed mechanism to form the controlled helical-axis orientation of the Cho-LC in thepolymer particles.
We obtained the super-monodispersed Cho-LC polymer particles with a diameter of 2.6 ±0.1 µm. We confirmed that the monodomain of the Cho-LC orientation was formed in the particles. In
addition, we succeeded in controlling the orientation of helical axis of the Cho-LC in the particles, andradial helical-axis orientation was formed in the particles. The reporting Cho-LC polymer particles canbe easily and efficiently prepared by the common way, dispersion polymerization, which isindustrially utilized to manufacture polymer particles. Due to the controlled helical axis orientation of
Cho-LC, the particles showed unique optical properties and can have highly potential application as
optical materials with recognition abilities of a reflection color and a circular polarization of light.

O22

Unidirectional alignment of polymer-grafted ZnO nanorods inliquid-crystalline polymer films
Kaho Ogata1,2, Yoshiaki Kobayashi1,2, Kohsuke Matsumoto1,2, Shoichi
Kubo1,2*, Atsushi Shishido1,2*

1 Laboratory for Chemistry and Life Science, Institute of Innovative Research,
Tokyo Institute of Technology, Japan
2 Department of Chemical Science and Engineering, School of Materials andChemical Technology, Tokyo Institute of Technology, Japan*kubo@res.titech.ac.jp, ashishid@res.titech.ac.jp

Inorganic nanotubes and nanorods have attracted much attention due to their anisotropic properties
different from bulk materials. Of these anisotropic inorganic materials, ZnO nanorods show excellent
properties, e.g. wide bandgap, thermal and chemical stability, and anisotropic photoluminescence.
Controlling the alignment of ZnO nanorods is essential for developing functional devices by utilizing
their great potential. Although the alignment control of nanorods has been attempted by many methods[1–3], it is still a challenge to develop sophisticated methods for aligning nanorods over a large area.
We have recently proposed a simple method for the unidirectional alignment of ZnO nanorods on analignment layer [4]. In this method, ZnO nanorods grafted with liquid-crystalline (LC) polymers arealigned cooperatively with surrounding nematic LC molecules. In this study, we demonstrate theunidirectional alignment of polymer-grafted ZnO nanorods in micrometer-thick LC polymer films.
Polymer-grafted ZnO nanorods were mixed with a polymerizable host LC monomer and aphotoinitiator, and ultrasonically dispersed. A glass cell was fabricated by adhering a pair of glass
substrates coated with an alignment layer. The sample mixture was injected into the cell at its isotropic
temperature, cooled down to LC temperature, and subsequently kept for 24 h. The photopolymerization
was conducted by the irradiation with ultraviolet (UV) light. The polarized optical microscopy andpolarized UV-visible absorption spectroscopy suggested that the nanorods were aligned together withhost LC moieties along the rubbing direction of alignment layer. The alignment of the nanorods was
also confirmed by transmission electron microscopy. Thus, the unidirectional alignment of polymergrafted ZnO nanorods in LC polymer films was successfully concluded.
References[1] L. Vayssieres, et al., Adv. Mater. 15 (2003) 464.
[2] O. Harnack, et al., Nano Lett. 3 (2003) 1097.
[3] R. Shenhar, et al., Phys. Chem. Chem. Phys. 12 (2010) 11885.
[4] S. Kubo, S. Hadano, et al., ACS Appl. Mater. Interfaces. 6 (2014) 811.

O23

Title：A Molecular Dynamics Study of Helical Columnar Liquid
Crystals Based on Propeller-Shaped Metallomesogens
Go Watanabe, 1, 2*, Mitsuo Hara3, and Jun Yoshida4

1 School of Science, Kitasato University, Japan
2 Kanagawa Institute of Industrial Science and Technology
2 Graduate School of Engineering, Nagoya University, Japan
3 College of Humanities and Sciences, Nihon University, Japan* go0325@kitasato-u.ac.jp

A calamitic liquid crystal (LC) composed of rod-shaped (calamitic) molecules is known to betransformed into chiral nematic LC with a helical structure upon doping with chiral molecules. The
effect of molecular chirality for the calamitic LCs has been well investigated thus far. The helicalstructures can be also observed in the columnar LCs mainly formed by disc-shaped molecules. While
helical columnar LCs have attracted widespread research attention[1], the correlation between
molecular chirality and the helical structure induced is not perfectly understood.
Recently, we found that a type of octahedral metallomesogen molecules, Ru-C8 (Fig. 1a), having
propeller-shaped chirality at the molecular core (ΔΛ chirality) exhibits the hexagonal columnar LC
possessing helical structure at room temperature. While the experimental studies revealed that thebasic information about the helical structure, its details were clarified by performing all-atom
molecular dynamics (MD) simulation. The structure obtained from MD simulation shows that themolecules stack with both the molecular position and C3 axis rotating along the column axis (Fig. 1b).
It indicates that the structure was classified as a hybrid of two major proposed helical stacking types.
Further analysis based on the MD simulation results highlights the interplay of the steric repulsion
between the chiral cores, π-stacking, and dipolar interaction in the helix formation.[2]This work was supported by JSPS KAKENHI Numbers JP19H02537 and 19H05718.

Fig. 1 (a) Molecular structure of Δ-Ru-C8 and (b) top view (left) and side view of asingle column (center) of Δ-Ru-C8 after 200 ns of MD simulation andschematic of a single column structure
References[1] T. Sierra et al., Chem. Soc. Rev., 38, (2009), 781.
[2] G. Watanabe, M. Hara, J. Yoshida et al., Chem. Commun., 56, (2020), 12134.

O24

Nonlinear geometric phase lensing from liquid crystals
Samlan Chandran Thodika* and Etienne Brasselet
University of Bordeaux, CNRS, France* samlan.chandran-thodika@u-bordeaux.fr

Patterning the orientation of liquid crystals is a well-known way to encode arbitrary optical phaseprofile of a geometric nature within physically flat optical elements, which has led to the advent of a
nowadays mature liquid crystal photonic technology. One of the simplest practical example is that ofgeometric phase lenses, whose convergent or divergent nature can be controlled by the handedness of
the incident circularly polarized light. Recently, such geometric phase lensing met the nonlinear optics
of liquid crystals in the framework of so-called ‘nematicons’, which deal with self-trapping of light asa results of localized optical induced liquid crystal reorientation, as reported by Jisha and coworkers[1]. The latter work discusses the experimental observation of self-trapping of light in a particular
light-matter interaction geometry interpreted as being the result of propagation dependent spin angularmomentum transfer from light to matter. This eventually leads to alternating in-plane twisting of thedirector field, thereby realizing a continuum nonlinear version of a previous linear optics, static,
discrete one [2]. Still, the direct identification of the basic physical process at play—the nonlinear
geometric phase lensing—remains elusive so far. Here we report on its experimental identification
based on a simple experimental scheme, which should foster further works on the nonlinear spin-orbit
photonics of liquid crystals.
References[1] C. P. Jisha, A. Alberucci, J. Beeckman, and S. Nolte, Self-Trapping of Light Using thePancharatnam-Berry Phase, Physical Review X 9, 021051 (2019).
[2] S. Slussarenko, A. Alberucci, C. P. Jisha, B. Piccirillo, E. Santamato, G. Assanto, and L. Marrucci,
Guiding Light via Geometric Phases, Nature Photonics 10, 571 (2016).

O25

TwistedNematic
LiquidCrustal
DeviceUsing
Hydrogen-Bonded Liquid Crystal for Terahertz Frequency
RegionRyota Ito1*, Hayato Sekiya1, Michinori Honma1 and Toshiaki Nose1

1 Faculty of Systems Science and Technology, Akita Prefectural University,Japan* r_ito@akita-pu.ac.jp

Terahertz waves have attracted significant attention for many years, mainly because of theirpromising applications including post-5G communication technologies and terahertz sensing/imaging
such as nondestructive testing [1,2]. Liquid crystal (LC) materials are important for tunable devices interahertz frequency because of their controllability with low drive voltage and low power consumption.
However, many LC materials usually exhibit large dichroism in the terahertz region. This dichroism
can cause some deformation of polarization state in the LC-based terahertz wave control devices.
Previously, we showed that a hydrogen-bonded LC exhibits no dichroism at 2.5 THz [3]. We believethat the hydrogen bonding has important role not only in supramolecular LCs [4] but also in LCs forterahertz devices. In this study, we introduce the hydrogen-bonded LC to the twisted nematic (TN) LC
device and investigate operation properties of the TN LC device in the terahertz frequency region.
Fig. 1 indicates the transmittance of TN LC device using hydrogen-bonded LC PC29 (LCC,
Yamanashi Japan). The polarization state of terahertz wave passing through the TN device wasmeasured by using an optically pumped gas laser as a continuous wave terahertz source. We placed
the TN LC device between two wire-grid polarizers, and the intensity of the terahertz wave was
detected by a pyroelectric detector. In fig. 1, we show the terahertz wave transmittance as a function ofanalyzer angle A. We set the angle of polarizer P = 90 deg, and the analyzer angle A = 0 deg
corresponds to the crossed Nicols. Since the minimal transmission is almost zero, linear polarizedterahertz wave was rotated almost 90 deg in the TN LC device keeping its polarization state.
Furthermore, owing to the isotropic losses of the PC29 at 2.5 THz, the polarization direction isswitched without changing intensity by applying electricfield to the TN device (see on state in fig.1). We believethat utilization of the hydrogen-bonded LCs in theterahertz tunable devices is powerful technique forcreating applications such as ultra-fast terahertz wirelesscommunication and terahertz imaging.
Fig. 1 Transmittance of TN LC device
Referencesusing hydrogen-bonded LC at 2.5 THz.
[1] M. Tonouchi, Nat. Photonics, 1, 97 (2007).
[2] W. Withayachumnankul, et al., Adv. Opt. Mater., 6, 1800401 (2018).
[3] R. Ito et al., Applied Sciences, 8, 2478 (2018).
[4] T. Kato, et al., J. Am. Chem. Soc., 111, 8533 (1989).

O26

Embedded optical ring resonators based on photoalignment
B. Berteloot*1, I. Nys1, X. Xue1, J. Beeckman1, K. Neyts1

1 Liquid Crystals and Photonics group, ELIS, Ghent University, Belgium* brecht.berteloot@ugent.be

Optical waveguides consist of a core and a cladding. To confine the light in thecore of the waveguide, it is required that the refractive index of the core n core islarger than the refractive index of the cladding nclad. Nematic liquid crystals (LC)are birefrigent and have an ordinary refractive index no and an extraordinaryrefractive index ne. These indices can be used to build a confined waveguide in
the LC bulk.
Using a novel patterned photoalignment technique we demonstrate the ability todefine specific alignment orientations at the substrates of a nematic LC cell thatwill lead to complex 3D configurations. In these configurations there are welldefined regions in which the LC is oriented in such a way that the effective
refractive index is higher than in the neighborhood, leading to the occurrence ofan optical waveguide. [1]More specifically, we demonstrate the fabrication of ring shaped regions withrotational symmetry. The 3D configuration is structured in such a way that the
optical properties of the waveguide are maintained along the entire ring. [2]Fig. 1: LC based ring resonator investigated using polarization microscopy, Finite Element (FE),Beam Propagation Method (BPM) and waveguide mode simulations.
References[1] B. Berteloot et al., Soft matter, 16, 4999-5008, (2020).
[2] B. Berteloot et al., Journal of Molecular Liquids, (accepted).

O27

Polymerizable self-organizing photonic structures based onnematic liquid crystals
Piotr Lesiak1, Miłosz Chychłowski1, Karolina Bednarska1, Wiktor
Lewandowski2, Martyna Tupikowska2, Tomasz R. Woliński1
1 Faculty of Physics, Warsaw University of Technology, Warsaw, Poland
2 Faculty of Chemistry, University of Warsaw, Warsaw, Poland* piotr.lesiak@pw.edu.pl

Nematic liquid crystals (NLCs) doped with nanoparticles are used in various photonic systems.
Depending on the specific type of nanoparticles (metallic, ferroelectric, dielectric, etc.) as well on theirsize, shape, concentration or surface coating [1–4] NLCs doped with nanoparticles may exhibit different
properties. Metallic nanoparticles show great promise in device applications due to their ability to
improve liquid crystal performance. An interesting effect in a composite consisting of gold nanoparticles
and a NLC matrix is spontaneous formation of the photonic structure that was observed two years ago[5]. A self-creating one dimensional photonic crystal (Fig. 1) may allow a design as well fabrication ofspectrally adjustable optofluidic photonic devices with a broad tuning range. This self-assembly process
is completely reversible and can be controlled by modifying diameter of the confining space.
Consequently, a period of the observed self-organizing structure depends on the capillary diameter andvaries in the range from 10 to even 60 m. Additionally, the whole system is characterized by highrefractive index contrast as the refractive index is being changed between nematic phase and isotropic
phases. A significant difficulty in studying properties of the periodic photonic structure is its
stabilization in a very narrow temperature range. The use of cross-linking process helps to obtain thestability of the photonic system structure at lower temperatures [6]. For this purpose, a nematic liquid
crystal doped with gold nanoparticles was combined with a small amount of a mixture consisting of amonomer and a UV-sensitive activator. In this work we present a way for constructing and developing
enhanced temperature stability of self-organizing photonic structures based on nematic liquid crystals.

Fig. 1. One dimensional photonic crystal in nematic liquid crystal doped with gold nanoparticles
References[1] T. Hegmann, et al., J. Inorg. Organomet. Polym. Mater. 17 (3) (2007) 483–508.
[2] O. Stamatoiu, et al., in: C. Tschierske (Ed.), Liq. Cryst. Top. Curr. Chem., vol. 318, Springer, Berlin,
Heidelberg, 2011.
[3] U. Shivakumar, et al., Liq. Cryst. 38 (11–12) (2011) 1495–1514.
[4] S. Orlandi, et al., Phys. Chem. Chem. Phys. 18 (2016) 2428–2441.
[5] P. Lesiak, et al. ACS Nano (2019), 13, 10154–10160.
[6] K. A. Rutkowska, et al., Phot. Lett. Pol., vol. 10, no. 1, pp. 11-13, (2018)

O28

Tunable liquid crystal optical microcavities for topologicalphotonics
Jacek Szczytko1*, Mateusz Król1, Katarzyna Lekenta1,
Przemysław Oliwa1, Rafał Mazur2, Przemysław Morawiak2,
Przemysław Kula2, Wiktor Piecek2, Michał Matuszewski3,
Witold Bardyszewski4, Helgi Sirgudsson5,6,
Pavlos G. Lagoudakis5,6, Barbara Piętka1

1

Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Poland
Institute of Applied Physics, Military University of Technology, Warsaw, Poland
3
Institute of Physics, Polish Academy of Sciences, Warsaw, Poland
4
Institute of Theoretical Physics, Faculty of Physics, University of Warsaw, Poland
5
School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, UK
6
Skolkovo Institute of Science and Technology, Moscow, Russian Federation*e-mail: Jacek.Szczytko@fuw.edu.pl
2

The performance of novel kind of a tunable optical microcavity consisting of a nematic liquid
crystalline birefringent optical medium enclosed in a typical Fabry-Perot resonator has been studied [1].
The large freedom of molecular reorientation, allow for convenient control of eigenmodes of lightpropagating through optical cavity while driven by relatively weak external electric fields. With theability to manipulate the permittivity tensor and, therefore, effective refractive indices for different
polarizations of light it is possible to tune the energy splitting between cavity modes which strongly
influences the transmission, reflection and luminescence (if doped with a dye). Our observations can beinterpreted in terms of spin-to-orbital angular momentum conversion, which conserves the angularmomentum of the excited photons when they convert from one spin to the other through the spin–orbit
coupling of light [2] (where “spin” represents polarization of light). Our novel device allows forgeneration and observation of various topological light polarizations like so-called persistent spin helix,
i.e. polarization stripes [3] and complex polarization whirls like first and second-order merons and antimerons [4] (Figure). In the future it allows for the integration of Bose-Einstein exciton-polariton
condensates into the room-temperature operating devices.

Figure. a) Scheme of the tunable LC microcavity and b) dispersion relation of circularly polarized lighttransmission [2]; c) observation of so-called persistent spin helix of light [3] and d) topological state of light:
second order anti-meron of light polarization [4].
[1] K. Lekenta et al., Tunable optical spin Hall effect in a liquid crystal microcavity. LIGHT SCI. APPL. 7, 74(2018), DOI:10.1038/s41377-018-0076-z[2] K. Rechcińska et al. Engineering spin-orbit synthetic Hamiltonians in liquid-crystal optical cavities
Rechcinska, SCIENCE 366 (6466), 727 (2019), DOI:10.1126/science.aay4182[3] M. Król et al Old experiments in new light: Young's double-slit and Stern-Gerlach experiments in liquid
crystal microcavities https://arxiv.org/abs/2104.09674[4] M. Król et al. Observation of second-order meron polarization textures in optical microcavities, OPTICA 8,
255-261 (2021) DOI:10.1364/OPTICA.414891

O29

Title： Reflective optical components based on chiral liquid
crystal for head-up displays
Migle Stebryte*, Inge Nys, Jeroen Beeckman, and Kristiaan Neyts
LCP group, ELIS department, Ghent University, Belgium* migle.stebryte@ugent.be

Augmented reality and head-up displays have inspired new applications for flat optics. One of the ways
to realize a virtual image in such displays is to use flat diffractive components based on chiral liquid
crystal (CLC). CLC is a soft material that can self-organize into a periodic helical structure that strongly
reflects visible light. Combining this property with a variation of the optical axis in a liquid crystal layer
results in a reflective diffractive optical component that can diffract the light with a high efficiency overlarge angles and is polarization sensitive. The before-mentioned variation of the optical axis is achieved
using a photo-alignment technique, which allows us to reach a sub-micrometer period. Using thismethod, we can obtain a range of reflective photonic components that can be used in head-up display
systems. In the past, we reported diffraction gratings that are only a few micrometers thick and have an
efficiency of over 90% [1]. In this work, a range of new reflective optical components, such as reflective
lenses, is realized and investigated. We also further investigate the theory behind the simple reflective
diffraction grating and suggest an analytical model to estimate the director configuration in the bulk ofsuch a structure and to simulate optical behavior of the device [2].
References[1] I. Nys, et al., Advanced Optical Materials, 7, 1901364 (2019).
[2] M. Stebryte et al., Crystals, 10, 807, (2020).

O30

Liquid crystal microlenses based on binary surface alignment
Artur R. Geivandov*, Serguei P. Palto, Irina V. Kasyanova,
Ivan V. Simdyankin, Vladimir V. Artemov, Maxim V. Gorkunov
Institute of Crystallography, FSRC “Crystallography and Photonics”,
Russian Academy of Sciences, Moscow, Russia*ageivandov@yandex.ru

We report the formation of high optical power
microlenses (Fig. 1) in the near-surface region of theliquid crystal layer. Such microlenses, possessing a verysmall focal length f at a rather large aperture A (f/A~2),
are able to focus the light into spots of a characteristic
size comparable with the wavelength (Fig. 2). Using
numerical modeling, a specific profile of patterning ofan LC alignment surface by an ion beam [1] is proposed
to provide the orienting properties necessary for theformation of an array of microlenses with a focal lengthcomparable to the LC cell thickness. The proposed
microlens arrays are produced and their opticalproperties are discussed.
Optical measurements of the focal length of the
microlenses with a microscope give a value of ~35 µm.

Fig. 1. a) Model of a 30 um thick LC layer
with a profiled distribution of the director
in the x-direction on the surface Z0,
providing the properties of a cylindricalmicrolens; b) light intensity distribution
inside the LC layer calculated by FDTD
method3.0

aperture A) for the obtained lenses (f/A  2.3) turns out

2.5

to be higher than the simulated one, but, nevertheless,2.0

allowingclassifying

themicrolenses

as

fast

(wide-aperture).

IntensityThus, the F-number (the ratio of the focal length f to the

1.5

0.5

applications in LC photonics, for example, for the

0.0

fields inside the LC layer itself. These high-power fields
enable optical pumping in LC microlasers andopto-optical control of the liquid crystals themselves.

x=350 nm

1.0

The new microlenses can be useful for novel
formation of periodically distributed intense optical

x-polarizedy-polarized

-8

-6

-4

-2

0

x(m)

2

4

6

8

Fig. 2. Light intensity distribution at awavelength of 450 nm in the focal plane
for the calculated cylindrical LC microlens
having 15 um width.

References[1] M. V. Gorkunov et al. Beilstein J. Nanotechnol. 10 (2019) 1691.

O31

Selective light diffusion of polymer network liquid crystals
formed through photopolymerization induced phase separation
by nonuniform photoirradiation
Hiroshi Kakiuchida1* and Akifumi Ogiwara2

1 Innovative Functional Materials Research Institute, National Institute ofAdvanced Industrial Science and Technology, Japan
2 Department of Electronics Engineering, Kobe City College of Technology,Japan* h.kakiuchida@aist.go.jp

Light diffusers are fundamental but indispensable in opticaland photonic applications, such as beam homogenization,
opticalattenuation,andprivacyprotection.

Suchapplications demand different properties in light scattering,and various light diffusers have been developed using
polymer network liquid crystals (PNLCs), such as
hemispheric and unidirectional light diffusers [1,2]. PNLCs
basically consist of phase-separation structures of liquid
crystals (LCs) and polymers at a (sub)micron scale, and areversatilely applicable using the features of LCs, namely,

Fig. 1 Snapshots of wall clock
looked through the sample andlight distribution of green laser
scattered from the sample, when
the direction of light polarization is(a) horizontal and (b) vertical, as
expressed by arrows.

anisotropic molecular structures and extrinsic-stimulative responses. We have developed diffusive anddiffractive structures through a self-assembly process or photopolymerization induced phaseseparation (PPIPS) conducted by nonuniform photoirradiation technique [3,4].
Using this technique, we fabricated here light diffusers differently depending on optical polarization,
scattering direction, and temperature. Figure 1 shows snapshots of light diffusion selective at a specificpolarization azimuth to a specific scattering direction. The PNLCs were formed through PPIPS
conducted by projection of anisotropic speckle patterns onto the raw mixtures of nematic LCs (5CB)and mixed monomers (AH600, DCPA, Ho, etc.). As shown in Fig. 2, micron-scale anisotropic
domains were formed, and LC molecular orientation was uniaxially ordered in the domains. The
vertically anisotropic domains produced light scattering intensive specifically in the horizontal
direction, and the uniaxially orientation order of LC molecules in thedomains linearly polarized the light scattering, as shown in Fig. 1.
The nonuniform photoirradiation techniques are flexible and easy
but practical for developing various advanced light diffusers.

References[1] L. Zhou, et al., RSC Adv. 8 (2018) 40347.
[2] Y. Horii, et al., IEICE Trans. Electron. E101-C (2018) 857.
[3] H. Kakiuchida, et al., ACS Omega 2 (2017) 6081.
[4] H. Kakiuchida, et al., ACS Appl. Mater. Interfaces 11 (2019) 19404.

10 µm

Fig. 2 Anisotropic phaseseparation structure of
PNLC observed polarizing
optical microscope at±45° crossed-Nicols state,
as expressed by cross.

O32

Fast and Slow Tuning of Molecular Recovery Response ofCholesteric Liquid Crystal Elastomers in Layered System
Kyohei Hisano1*, Seiya Kimura1, Norihisa Akamatsu2, Atsushi Shishido2,
Osamu Tsutsumi1*

1 Department of Applied Chemistry, Ritsumeikan University, Japan
2 Laboratory for Chemistry and Life Science, Tokyo Institute of Technology,Japan* hisano@fc.ritsumei.ac.jp, tsutsumi@sk.ritsumei.ac.jp
Liquid crystal elastomers (LCEs), with strong coupling of molecular orientation order andmacroscopic elasticity of polymer networks, changes their material properties of molecularreorientation under external stimuli, leading to realize stimuli-responsive applications that work in thefield of soft-robotics, flexible sensors, and so on. Although such molecular reorientation is very fast
when stimulus applied, the recovery response after stimulus removal is relatively slow due to the slow
relaxation of polymer networks and molecular orientation order. Very recently, a synthetic approach
has succeeded to tune the speed of recovery response; in some case, however, the modification ofmolecular structures might deteriorate materials properties. Considering the strong coupling between
the molecular orientation and materials shape of a LCE, the recovery response can be tuned bylayering it with other layers with desired mechanical properties. Here we have investigated thislayered system to arbitrary tune the molecular recovery response of LCEs. For visualizing molecularorientation order facilely, we employed a cholesteric liquid
helically twisted molecular orientation and reflective color
appearance due to Bragg reflection depending on the helicity.
The synthesized cholesteric LCEs clearly showedreflection color; and the color was blue-shifted under tensile

Normalised reflectancecrystal as an internal LCE layer because cholesteric medium, has

1.2

The single-layered LCE exhibited typical viscoelastic response

microscopic molecular orientation and macroscopic shape(Figure 2). Furthermore, by changing external layers, we could
tune the speed of recovery response, e.g. << 1 s or > 6 months,
without any modification of molecular structure of LCEs. We
demonstrated the cholesteric LCEs acting as a sensor detecting aspatiotemporal strain by using a commercially available camera.

0.4
0.2
500
600
700
Wavelength (nm)800

λ peak (nm)640

Applied strain (%)

showed fast recovery response with no residual strain both in

0.6

Figure 1. Reflection spectra of thecholesteric LCE under tensile
strains of 0–50%.

behavior after stimulus removal. On the other hand, the film
layered by rubbery materials of polydimethylsiloxane (PDMS)

0%
10%
20%
30%
40%
50%

0.8

0
400

elongation reversibly (Figure 1). For evaluating molecular
recovery response, we applied square-wave strain on the film.

1.0

600
560
520
30
20
10
0

20

40

60
80
Time (s)100120Figure 2. Time courses of thechange in reflection wavelength of
the PDMS layered film under 5–
30% tensile strains.

O33

Confocal Observation of Reconnecting disclination lines in
Nematic Liquid Crystal
Yohei Zushi1* and Kazumasa A. Takeuchi1,2

1 Department of Physics, The University of Tokyo, Japan
2 JST PRESTO, Japan* zushi@noneq.phys.s.u-tokyo.ac.jp

In nematic liquid crystals, singularities in the director field appear as disclination. Disclination lines inthree-dimensional liquid crystal move with deformation in observable timescales. The motion of
disclination lines is expected to depend not only on the location and shape of the disclination but also
on the director profile around disclination. Currently, the relationship between the motion of
disclination lines and the director profile has been actively studied also in biological systems such as
microtubule bundles, bacterial populations, and morphogenesis.
Here we aim at direct three-dimensional measurements of dynamics of disclination lines. Using
fluorescent dyes and confocal microscopy, we successfully observed the three-dimensional dynamics
of disclination lines (Fig. 1). We analyzed reconnections, which are a characteristic phenomenon of
disclination lines, and determined a scaling law describing the distance between disclinations. Further,
we found asymmetry in the speed of the two disclinations toward the reconnection. A possible causeof the asymmetry is the difference in the curvature of the two disclination lines, but this alone is foundto be quantitatively insufficient. Consideration of the director profile around the disclinations suggeststhat the asymmetry in the director profile gives a major contribution to the asymmetry in the motion.

Fig. 1 Three-dimensional confocal microscopy images of reconnection of
disclination lines in nematic liquid crystal

O34

Low voltage fast driving of vertical aligned ferroelectric liquid
crystal devices by nano-phase separation and gelation of ionicliquidYoichi Takanishi*1,2, Isa Nishiyama2,3, Jun Yamamoto1,2

1 Graduate School of Science, Kyoto University, Kyoto, Japan
2 JST-CREST, Japan
3 Japan Advanced Institute of Science and Technology, Ishikawa, Japan* ytakanis@scphys.kyoto-u.ac.jp

Yamamoto et al. recently invented the principle and design of the “Slippery interface”, which has
zero (or almost zero) anchoring at the substrate interface, and the response of the vertically aligned
ferroelectric liquid crystal (VA-FLC) was drastically improved (low driving voltage)[1]. Furthermore,
we utilized the localization of ionic liquid to the electrode by polar interaction, and fixed the ionicliquid at the electrode part by gelling. As a result, we achieved further reduction of driving voltage[2],but there is a problem that the slow response component was dominated in the transmittance. If thestructure could be divided in some way and the co-operative motion of helix unwinding by applied
electric field could be localized, it is expected to lead to a high-speed response. In this paper, we tried
to utilize nano-phase separation[3] composed of helical filament of B4 phase of bent-core molecules
and rod-like liquid crystals for dividing the helilcal structure of FLC. Combining the ionic liquid gel
and this nano-phase separation, we evaluated the electrooptic behavior of vertically aligned FLC.
Ionic liquid gel used was a mixture of CDBA6•Cl and 1-ethyl-3-methylimidazolium bis(fluorosulfonyl) imide (50 g/L). Bent-core molecule (P-8-OPIMB) was ca. 1wt% mixed into FLC, andfinally ionic gel was 20-50 wt% mixed into FLC mixture. This sample was inserted 3.5 µm-thick IPS
cell, and applied electric field treatment (±4 V/µm) was performed for several hours at 70°C in orderto accumulate the ionic liquid sol on electrode. Afterwards, ionic liquid was fixed on the electrode asa ionic liquid gel by cooling process. Electrooptic measurement was performed under the applicationof step-wise electric field.
Figure 1 shows the electro-optic response of VA-FLC without ionic liquid gel (violet), with ionicliquid gel (green), and with ionic liquid gel andbent-core liquid crystals (red) in 3.5 µm-thick
IPS cell under the applied step-wise electricfield (+1.5V/µm → 0 → –1.5V/µm→ 0). In
VA-FLC with ionic liquid gel, transmittancedrastically increases, which suggests the
reduction of driving voltage by introduction ofionic liquid gels.
Compared to VA-FLC only with ionic liquidgel, furthermore, a higher ratio of fast responsecomponents in transmittance was found in
VA-FLC with ionic liquid gel and bent-coreliquid crystals. This result suggests that thehelical structure of FLC was divided due to thenano-phase separation and co-operative motion Fig. 1 : Electro-optic transmittance of three types
of VA-FLC in 3.5 µm-thick IPS cell under theof helix unwinding becomes faster.
applied step-wise electric field of 10 Hz at 65°C.
Acknowledgement

This This study was supported by JST-CREST（Grant No. JPMJCR1424）.

References[1] J. Yamamoto et al., Proc. SPIE 10125, Emerging Liquid Crystal Technologies XII, 101250D (21April 2017).
[2] Y.Takanishi et al., FLC2019, Poster No.18 (Aug. 2019).
[3] Y.Takanishi et al., J. Phys. Chem. B, 118 3998-4004 (2014).

O35

Near-Field Diffraction from Self-Organized Topological
Defects Arrays in Nematic Liquid Crystals
Yuji Sasaki1*, Naoshi Murakami1, Keisaku Yamane1, and Hiroshi Orihara1

1 Division of Applied Physics, Faculty of Engineering, Hokkaido University,Japan* yuji.sasaki@eng.hokudai.ac.jp

Diffraction gratings are fundamental optical components that are used in many fields of science.
Nematic liquid crystals (NLCs) are interesting for tunable diffraction gratings because the opticalproperties can be controlled by external fields. For the study of the optical property of gratings,
fabrication of a spatially periodic director field is crucial. Recently, we found a simple method for
micropatterning the director field in NLCs in the macroscopic scale using homeotropically aligned
NLCs with negative dielectric anisotropy. Due to ions charged at the interfaces, the micropattern isspontaneously formed at the reorientation of the director field by an electric field. Moreover, the director
configuration exhibits defect structures often called umbilics, which are useful for optical vortex
generation. [1] In this system, it is possible to control the emergence of pattern formation by modifying
the surface anchoring condition. An example is shown in Fig. 1. When the director starts to reorient at
the threshold, we can observe an array of umbilical defects. Such a highly self-organized pattern isinteresting for both far- and near-field diffraction. In this presentation, we report near-field diffractionof NLC gratings consisting of topological defects arrays.

Fig. 1 An array of topological defects
induced by an electric field observed
under crossed polarizers. Scale bar,
400 μm.
References[1] E. Brasselet, Physical Review Letters 108 (2012) 087801.

O36

Helical Nanopores to Induce Chiroptic Function – Use of
Empty Spaces Created by Helical Nanofilaments
Fumito Araoka1*, Jae-Jin Lee2, Byeong-Cheon Kim2, Hyeon-Joon Choi2
and Suk-Won Choi2*
1 RIKEN Center for Emergent Matter Science, Japan
2 Department of Advanced Materials Engineering for Information andElectronics, Kyung Hee University, South Korea* fumito.araoka@riken.jp, schoi@khu.ac.kr

The B4 phase of some bent-core liquid crystals is an optically active state induced by the non-trivial
chiral superstructure of helically-twisting smectic layers. This helical structure, the so-called helicalnanofilament (HNF), is now understood as a result of the coupling of the saddle-splay curvature andthe chirality induced by the spontaneous molecular tilt in the smectic layers. HNFs are also known for
their excellent chiroptic functions, such as huge circular dichroism (CD) and optical rotation (OR)signals. The vividly- blueish optically segregated domains of the B4 phase has been reported alreadyin the first works by Watanabe ad Takezoe et al., and since then it has been dealt as one of thesymbolic chiral states of the bent-core liquid crystals [1].
Here in this work, we established an epoch-making method based on bottom-up templating for the
fabrication of a chiral nanoporous film that provides a chiral environment (chiral nano-space) to
induce the chiroptic functions [2-3]. HNFs of a bent-core molecule were utilized as athree-dimensional mold, and thus the fabricated chiral nanoporous film has an inverse nano-helix
structure. Upon refilling this inverse helix with an “achiral” nematic liquid crystal, distinct CD signals
appeared due to the transfer of chirality from the inverse helix to the achiral nematic liquid crystal.
The formation of the chiral superstructure wasconfirmed by the induction of CD signals. In addition,
the induced CD signals can be readily modulated byexternal stimuli, such as the application of heat or anelectric field. Amazingly, by refilling the chiral
nanoporous film with a fluorescent nematic liquid
crystal, it exhibits stimuli-responsive circularly
polarized

luminescence(CPL).

The

proposed

approach has huge potential for practical applications,such as for chiroptic modulators and switches andbiological sensors.

Fig. 1 Helical polymer structure fabricatedin the inversed helix replicated from HNFs
of the B4 phase of the bent-core liquid

crystal, P7.[3]References[1] T. Sekine, T. Niori, J. Watanabe, T. Furukawa, S.-W. Choi, H. Takezoe, J. Mater. Chem. 7 (1997) 1307.
[2] B.-C. Kim, H.-J. Choi, J.-J. Lee, F. Araoka*, S.-W. Choi*, Adv. Funct. Mater. 29 (2019) 1903246.
[3] J.-J. Lee, B.-C. Kim, H.-J. Choi, S. Bae, F. Araoka*, S.-W. Choi*, ACS Nano 14 (2020) 5243.

O37

Perovskite nanosheet liquid crystal gel with mechanochemical
structural color
Nobuyoshi Miyamoto1*, Wenqi Yang, 1; Kei-Ichiro Sueyoshi1, Shinya
Yamamoto,1 and Takumi Inadomi1
1 Graduate School of Engineering, Fukuoka Institute of Technology, Fukuoka,
Japan.

* miyamoto@fit.ac.jp.ac.jp

Inorganic nanosheets obtained by exfoliation of layered crystals have been investigated as intriguing
nanomodules for various functional materials. Under a certain condition, nanosheets dispersed in asolvent are spontaneously ordered to form liquid crystal phase with regulated superstructures[1]. In thisstudy, we prepared the layered perovskite nanosheet liquid crystals with lamellar-like periodic structurethat show structural colors and immobilized them in polymer gel by in-situ polymerization
technique,[2] in view of applications as stimuli-responsive soft materials.
The perovskite nanosheets (Inset of Fig. 1) were synthesized using the method reported previously.[1] To
obtain the composite gels, the monomer (N-isopropylacrylamide; NIPAm), crosslinker andphotoinitiator were dissolved into the nanosheet colloid and the mixture was irradiated with UV-light toproceed photo polymerization.
The nanosheet colloid showed pearl-like purple structural color, giving the maximum reflectancewavelength (λmax) of 555 nm in the visible reflectance spectrum. As the monomer was added, λmax shifted
to 521 nm, indicating the slight change of the interactions between nanosheets. Even after
polymerization, the structural color was retained (λmax = 684 nm), indicating successful immobilizationof the superstructure of the liquid crystalline
nanosheets. In the final state, considering the
Bragg-Snell law, the distance between thenanosheets is calculated as 257 nm. The gelpossessed high mechanical toughness with thecompressive breaking stress of up to 3 MPa due tothe reinforce effect by the nanosheets. The color of
the gel was changed from light pink to green andblue by mechanically compressing or stretching
the gel (Fig.1). The mechanochromic response
was reversible, fast (response time less than 1ms),
and highly sensitive to very weak stress of 1 kPa.

Fig. 1 The photograph of the gel with varied

structural color during a stretching test andthe schematic structure of the perovskite
nanosheet.

References[1] N. Miyamoto, S. Yamamoto, K. Shimasaki, K. Harada, Y. Yamauchi, Chem.Asian J. 2011, 6, 2936
[2] W. Yang, S. Yamamoto, K. Sueyoshi, T. Inadomi, R. Kato, N. Miyamoto, Angew. Chem. Int.
Ed. 2021, 60, 8466.

Magnetic Field-Responsiveness of Lyotropic LiquidCrystalline Polymer-Modified Fe3O4 Nanoplates

O38

Kiyoshi Kanie*, Chen She1, Masaki Matsubara, and Atsushi Muramatsu
Institute of Multidisciplinary Research for Advanced Material, Tohoku
University, Japan* kanie@tohoku.ac.jp

Hexagonal magnetite (Fe3O4) nanoplates are of great interest because of their marvelous properties
and wide range application in functional magnetic fluids and smart nanosensors. To control thedispersion of Fe3O4 nanoplates, polymers could be utilized to modify Fe3O4 nanoplates to induce thesynergistic effects of Fe3O4 and polymers. According to our previous research, iron(III) oxide(α-Fe2O3) particles and Fe3O4 particles with anisotropic shapes could be covered by thick polymers via
surface-initiated atom transfer radical polymerization (SI-ATRP)[1]. In the present study, hexagonal
Fe3O4 nanoplates obtained from the wet chemical reduction of α-Fe2O3 nanoplates were modified bypoly(methyl methacrylate) (PMMA) chains via SI-ATRP shown in Fig. 1a. Such PMMA-modified
Fe3O4 nanoplates indeed showed good dispersion stability, lyotropic liquid-crystalline (LC) properties,
and a fast response to an external magnetic field in ionic liquids. In particular, a TEM image in Fig. 1b
indicates that the PMMA-modified Fe3O4 nanoplates can show a nematic columnar structure after
applying an external magnetic field.
The nematic columnar structure along
magnetic field direction is a new
exampleforresponsivenesstheofmagnetic

lyotropic

LC

PMMA-grafted Fe3O4 nanoplates incompare with the stacked alignmentof unmodified Fe3O4 nanoplates in Fig.
1c.

Ultrasmall-angle

synchrotron

X-ray scattering measurements also
verified the uniaxially aligned nematiccolumnarstructure

of

PMMA-

modified Fe3O4 nanoplates in ionicliquids under an external magnetic
field[2] as shown in Fig. 1d. The
research results might be closely
connected

with

the

performance

improvements of functional magnetic
fluids and the design of new devices.

Figure 1. TEM images of (a) unmodified Fe3O4 nanoplates, and(b) PMMA-modified Fe3O4 nanoplates with nematic columnar
structure under magnetic field. The most plausible model: (c) A
stacked alignment of unmodified Fe3O4 nanoplates, and (d) auniaxial alignment structure of PMMA-modified Fe3O4
nanoplates under magnetic field.

References[1] J. Yabuki, M. Matsubara, Y. Takanishi, A. Muramatsu and K. Kanie, Chemistry Letters 46 (2016) 303.
[2] C. Shen, M. Matsubara, M. Yabushita, S. Maki, A. Muramatsu and K. Kanie, Nanoscale Advances 2(2020) 814.

O39

Ultrathin-film formation of liquid-crystalline
semiconductors for high performance transistorsorganic

Shunto Arai*

Faculty of Engineering, University of Tokyo, Japan* arai@ap.t.u-tokyo.ac.jp

Self-assembly of rod-shaped organic molecules is versatile to prepare various layered nanostructures,as investigated using smectic liquid crystals and amphiphilic systems. The unique feature of thesemolecules lies in the formation of layered molecular assemblies associated with the side-by-side
intermolecular interaction. This feature gains considerable attention in the field of organic
semiconductors, because it enables the formation of smooth channel/gate-insulator interfaces to obtainhigh-performance organic field-effect transistors (OFETs).
We have demonstrated that the ability to form thin layers is significantly improved using a classof rod-shaped π-conjugated molecules substituted by a single alkyl chain [1]. These materials afford
the formation of a bilayer-type structure, being reminiscent of cell membranes. Recently, we haveshown that these materials even afford the formation of self-assembled single molecular bilayers(SMBs), whose thickness uniformity extends over the area as large as wafer size scale (Fig. 1) [2-4].
To produce SMBs, a novel concept, geometrical frustration, is adopted in the film-formation technique.
In this technique, two molecules with different alkyl chain lengths are contained in the solution [2].
The use of the mixed solution can effectively suppress the interlayer stacking while maintaining theintralayer molecular arrangements between π-conjugated molecules [2, 3]. The obtained SMBs afford
the OFETs showing efficient two-dimensional carrier transport [4]. This finding should open a new
route

to

SMB-based

ultrathinsuper-flexible electronics.
References[1] T. Hamai et al., Phys. Rev. Appl.
8 (2017) 054011.
[2] S. Arai et al., Adv. Mater. 30(2018) 1707256.
[3] S. Arai et al., Adv. Funct. Mater.
30 (2020) 1906406.
[4] G. Kitahara et al., Sci. Adv. 6(2020) eabc8847.

Fig. 1 Formation of the wafer-scale single molecularbilayer (SMB). (a) (Left) Schematic for two kinds of liquid
crystalline organic semiconductors (Ph-BTBT-Cn) withdifferent alkyl chain lengths. (right) Schematic forgeometrical frustration induced by chain-length disorder.
(b) A photograph of the wafer-scale SMB. (c) Typicaltransfer characteristics of the SMB-based OFET.

O40

Photo-induced phase transitions of calamitic-discotic
bimesomorphic azobenzene-triphenylene liquid crystals
Hiroto Nakamura1, Hikaru Sanada1, Daisuke Tanaka1, Ryota Minobe1,
Mitsuo Hara2, Shusaku Nagano2, Tsuyoshi Kawai3, Takahiro Seki2, Kingo
Uchida1* and Yo Shimizu 3*

1 Graduate School of Science and Technology, Ryukoku University, Japan
2 Graduate School of Engineering, Nagoya University, Japan
3 Graduate School of Science and Technology, Nara Institute of Science andTechnology (NAIST), Japan* yo-shimizu@ms.naist.jp, uchida@rins.ryukoku.ac.jp

A novel type of liquid crystal, calamitic-discotic
bimesomor-phic azobenzen-triphenylene derivative(1-C14-3) which exhibit both calamitic SmA anddiscotic Colr mesophases by way of the change ofmolecular conformation [1, 2]. have also a potential
as a photo-responsive material evidenced by the factthat 1-C14-3 shows photo-induced bimesomorphic
phase transitions as shown in Fig. 1. To clarify themechanism, GI-SAXS method was applied to thealigned cells with homeotropic and planar alignments

1-C14-3in the SmA phase.
Fig. 2 shows GI-SAX images of homeotropicallyaligned SmA phase. It was found that the photoirradiation makes the layer spacing a bit shorter,
indicating the interdigitation of alkyl chains among layers
gets less, probably due to the trans-cis photoisomerization of azobenzene units and thus, the stabilityof SmA phase decreases under photo-irradiation.
Successive cooling leads to the formation of Colphase in a manner of arrangement for

Fig. 1 Phase transition diagram
under photo-irradiation at 365 nm.

the columnar axis which is comparable
to the case of thermal phase transition.
References[1] Y. Shimizu, A. Kurobe, H. Monobe, N.
Terasawa, K. Kiyohara and K. Uchida,
Chem. Commun. (2003) 1676.
[2] D. Tanaka, H. Ishiguro, Y. Shimizu andK. Uchida, J. Mater. Chem., 22 (2012)
25065.

Fig.2 GI-SAXS images of homeotropically aligned
SmA phase obtained on cooling from Iso phase.

O41

Polarization-Maintainable
Axially
Polar
Ferroelectric
Columnar Liquid Crystal Phase Realized by Introducing
Chirality
Keiki Kishikawa1,2*, Azumi Akiyama1, Keita Jido1, Tatsuo Taniguchi1
and Kohri, Michinari1
1 Graduate School of Engineering, Chiba University, Japan
2 Molecular Chirality Research Center, Chiba University, Japan*kishikawa@faculty.chiba-u.jp

Axially polar ferroelectric columnar (AP-FCLC) phases, in which the polarity along the column axis isswitchable by applying an external electric field, and is maintained even after the electric field isremoved, have attracted much attention. If the polar direction of each column is switchable with anano-sized electrode, an ultra-high density memory device can be achieved. Recently, many
examples were reported as AP-FCLC phases, and their hysteresis loops and/or switching current peaks
were shown as evidence of ferroelectricity. However, most examples are done at high frequencies thatpolarization relaxation cannot keep up with, and very few studies focus on polarization maintenance(PM) after removal of the electric field. We would like to distinguish between the phase that shows
PM and the phase that does not show PM, and believe that PM is the most important property torealize the above-mentioned memory devices. So, since 2005, in liquid crystal (LC) urea compounds,
we have been aiming for realization of a polarization-maintainable AP-FCLC phase that perfectly
maintains its polarization even after removal of the voltage.
In this talk, we report on a polarization-maintainable AP-FCLC phase and the mechanism for realizing
the phase. The six achiral alkyl chains in N,N’-bis(3,4,5-trialkoxyphenyl)ureas Urea-n were replacedwith (S)-citronellyl groups in (S)-1. Surprisingly, the columnar LC phase of (S)-1 showed perfectferroelectricity. Furthermore, the polarization directions were switchable by applying a rectangularwave voltage, and the induced polarization was maintained after removal of the electric field.
Second harmonic generation (SHG)
experiments were performed to investigate
the polarization states of Urea-10 and (S)-1,
respectively.
Both compounds in thecolumnar phase showed strong SHG signals
as soon as 100 VDC was applied. After
turning off the voltage, the SHG signal for
Urea-10 disappeared immediately, but thatfor (S)-1 was maintained at the same level
for at least 10 h. Helical column formation
caused by the introduction of chirality is
assumed to play an important role inachieving the ferroelectricity.
References[1] K. Kishikawa, S. Nakahara, Y. Nishikawa, K. Yamaguchi, S. Kohmoto, M. Yamamoto, J. Am. Chem.
Soc. 127 (2005) 2565.
[2] A. Akiyama, K. Jido, M. Kohri, T. Taniguchi, K. Kishikawa, Adv. Electron. Mater. 6 (2020),
2000201.

Poster Abstracts

P1

Title ： Development of Novel Chiral Molecules with High
Helical Twisting Power
Shogo.Yamauchi1*, and Seiji.Kurihara1*and Tuyoshi.Fukaminato1* andSunnam.Kim1*and Yoshi.Ohta2*and Fuminoni.Satou2* and Maki.
Kamikubo2* and Shunta.Nabetani2*
1 Kumamoto University, Japan
2 Research Division,Nissan Motor Co.,Ltd* kurihara@kumamoto-u.ac.jp

When a chiral molecule is added to a nematic liquid crystal, a cholesteric phase with a helicalstructure is formed. The force that induces the helical structure is called helical twisting power(HTP). The twisting power of the chiral azobenzene compounds is decreased,ΔHTP, by
ultraviolet irradiation to cause trans-cis photoisomerization of the azobenzene compounds. We
have reported reversible photoswitching of transparent and light-scattered states by controllingthe balance of HTP between photochromic and nonphotochromic chiral dopants [1]. The
development of chiral molecules with large HTPs and ΔHTPs is essential to achieve highly
efficient switching with a small amount of dopant. Recent studies have shown that binaphthytl
derivatives exhibit high HTPs and high Δ HTPs. In this study, we synthesized several
compounds with alkyl chains and liquid crystalline units introduced into binaphthyl derivatives(Fig.1) and studied their HTP and ΔHTP values.

Group AGroup B

Linker C

Fig.1 Molecular structures of photochromic and nonphotochromic chiral compounds.
Reference[1]S.Kurihara et.al , chem Eur.J 13 (2007) 2641.

P2

Analysis of Angular Dependence of Band Edge Wavelengths
in Cholesteric Mirror and Bragg-Berry Cholesteric Deflector
Ryotaro Ozaki1*, Shunsuke Hashimura1, Kadowaki Kazunori1,
Hiroyuki Yoshida2, and Masanori Ozaki2

1 Graduate School of Science and Engineering, Ehime University, Japan
2 Division of Electrical, Electronic and Information Engineering, Graduate
School of Engineering, Osaka University, Japan* ozaki.ryotaro.mx@ehime-u.ac.jp

Patterning of the liquid crystal director in cholesteric liquid crystals (ChLCs), or control in the
structural phase of the helical structure, enables circularly polarized light to be diffracted [1]. Although
the selective reflection phenomenon in a conventional ChLC mirror has been the subject of thoroughinvestigation and is well understood, recently a new simple approximation model for estimating bandedge wavelengths of selective reflection from ChLCs for oblique incidence has been proposed [2].
More recently, the approximation model has been developed for ChLC based holographic opticalelements, in which the band edge wavelengths and bandwidth of the selective diffraction aredetermined from simple equations [3]. In this study, we investigate angular dependence of the bandedge wavelengths in ChLC mirrors and deflectors using the approximation model andtwo-dimensional finite-difference time-domain (FDTD) method.

Fig. 1 Schematic of Bragg-Berrycholesteric deflector.

Fig. 2 FDTD calculation ofdiffraction from Bragg-Berrycholesteric deflector.

Fig. 3 Band edge wavelengths ofreflection and diffraction fromcholesteric mirror and Bragg-Berrycholesteric deflector.

References[1] J. Kobashi, H. Yoshida, and M. Ozaki, Nat. Photonics, 10 (2016) 389.
[2] R. Ozaki, Phys. Rev. E 100 (2019) 012708.
[3] R. Ozaki, S. Hashimura, S. Yudate, K. Kadowaki, H. Yoshida, and M. Ozaki, OSA Continuum, 2(2019) 3554.

P3

Aggregation Enhanced Room-Temperature Phosphorescencewith Dual Emission from Rod-Like Gold(I) Complexes
Andriani Furoida1, Kyohei Hisano1, and Osamu Tsutsumi1*

1 Department of Applied Chemistry Ritsumeikan University, Japan* tsutsumi@sk.ritsumei.ac.jp

Organic materials with aggregation-induced emission (AIE) are of increased interest due tothe broad practical application in optical devices and probes. Many types of organic AIE-active
molecules (AIEgens) have been reported. In particular, gold complex is one of the most attractive
AIEgen, owing to the ability to form dimeric compound via aurophilic interaction. We have reported
gold complexes with AIE properties, of which luminescence behavior is highly sensitive to not only
the molecular structure but also the structure of molecular aggregate.1 Therefore, controlling theaggregated structure is necessary to obtain the desired luminescence properties by molecular design.
In this study, a series of rod-like gold complexes were synthesized (Figure 1), and effects ofthe molecular structures on their photophysical properties were investigated. All gold complexes
showed strong emission in the crystal, but only weak emission was observed in the solution. The
emission properties of gold complexes in the crystal are affected by molecular structure. As shown in
Figure 2, in crystal, complexes containing biphenyl moiety (B2-5 and B3-5) exhibited an emission
band at ~500 nm. On the other hand, crystal of the complex containing cyclohexylphenyl moiety(CP-5) showed dual emission: a new emission bandOxappeared in the shorter wavelength region. The relativeAu

intensities of the dual emission bands could be controlled

Bx-5 (x = 2,3)

by excitation wavelength; thus, we could control theAuemission color of CP-5 crystal.

Figure 1. Molecular structure of goldcomplexes used in this study

observed emission from the gold complexes in crystal was

1.0

considered due to the tight packing structure of the crystal
which prevents the internal molecular motion and theoxygen penetration.

Normalized intensity

phosphorescence. In the crystal, even at room temperature(~23%). This intense room-temperature phosphorescence is

N

CP-5

The lifetime measurements revealed that thein air, they showed high phosphorescence quantum yieldN

B2-5 (λex 344 nm)
B3-5 (λex 352 nm)
CP-5 (λex 290 nm)

0.8
0.6
0.4
0.2

400

500
600
Wavelength

700

800

Figure 2. Emission spectra of goldcomplexes in the crystal
References[1] S. Yamada, Y. Rokusha, R. Kawano, K. Fujisawa, O. Tsutsumi, Faraday Discuss., 196 (2017) 269

P4

Dynamic coupling of gel network and nematic orientation
order
Akinori Ooka1*and Jun Yamamoto1

1 Department of Physics, Graduate School of science, Kyoto University, Japan* ooka.akinori.42n@st.kyoto-u.ac.jp

We studied the dynamic coupling between orientation fluctuation of liquid crystals and conformation ofpolymers in the nematic gel (NG). The pre-cursor of the NG is made by heptyl-cyanobiphenyl (7CB), 8%
hexyl-cyanobiphenyl acrylate (LC-A), and 0.6/0.8% reactive mesogen (RM257) (similar mixture used in
the previous study[1]). We made the two NG by changing the cross-link density, high cross link density(LCLD NG) and low density (HCLD NG). A small amount of DMPAP used as a polymerization initiator.
We cured the sample by illuminating with UV lights (365 nm, 880 µW /cm2) for 30 minutes. We measure
the dispersion relation before and after polymerization of LCLD NG and HCLD NG (Fig.1 (a) and (b)).
(1) Before polymerization, both dispersion relations of the(a)orientation fluctuation for LCLD and HLCD NG are almostτ∝q-2

equivalent, and relaxation time is proportional to the inverse
square of q (~q-2) as predicted by the hydrodynamic theory.
(2) After polymerization, dispersion relation of LCLD
becomes about 5 times slower, but still proportional to ~q-2.

(b)

On the other hand, it should be noted that the relaxation time
becomes independent of q in the low q region for HLCD.
In order to investigate the spatial distribution of polymer
network in NG, we measured the position dependence of theretardation of the NG by 2D spectrometer, because the polymer
concentration directly relate the scalar order parameter of theorientation order. Since the wavelength dependence of theFig.1 Dispersion relations(a) LCLD NG (b) HCLD NG (30℃)(a)

transmitted light intensity should oscillate dependent on thebirefringence, we can analyze the size of the inhomogeneity of thespatial distribution of the polymer. Fig.2 show the observed image
for transmitted light intensity of LCLD NG and HCLD HG (Fig.2(a) and (b)). It can be confirmed that the size of the inhomogeneityof polymer reaches 0.1mm for LCLD NG whereas less than(b)

0.01mm for HCLD NG. In conclusion, in the cross-linking point
density for HCLD NG is enough to be percolated and sufficient
to confine the orientation fluctuation. This is because therelaxation frequency is independent of q in low q region as seenin the dispersion relation of polymerized HCLD NG.

References [1] C.C.C hang, et al. Phys. Rev. E 56, 595 (1997)

Fig.2 images by 2D spectroscope(a) LCLD NG (b) HCLD NG (44℃)

P5

Shape classification of liquid crystal elastomers with twist director configurations
Atsushi Joto1 , Haruka Doi1 , Valerio Varano2 , Luciano Teresi2 , Kenji
Urayama1*
1 Department of Materials Properties Control, Kyoto Institute of Technology, Japan
2 Department of Mathematics and Physics, University Roma Tre, Italy*urayama@kit.ac.jp

Introduction
Various types of deformation are thermally induced in liquid crystal elastomer (LCE) as a result of thecoupling of LC orientation and rubber elasticity by tuning the director configuration. The LCE ribbons
having twist director configurations (TNE) undergo a large change in helical pitch and diameter of thehelical shape in response to temperature variation [1]. However, it remains to be elucidated what governs
the helical shape. We investigate what type of parameter governs the shape of the TNE ribbons, andclassify the shapes depending on the geometrical features.
Experiment
The TNE ribbon specimens were made by using the method in Ref. [1]. The twist angle (χ) was varied
as 90, 135 and 180° by tuning the amount of chiral dopant. A ribbon specimen was cut out from the TNE
sheets so that the long axis had an angle (θ) with respect to the mid-director direction (Fig. 1). The angles
θ were varied from -90° to +90°.
Result & Discussion
We observe the shape changes driven by temperature variation in each TNE ribbon. We find that thehelical shapes at fixed temperature are classified into four types depending on θ, regardless of χ (Fig. 2).
The classifications are based on the helical handedness (right or left) and the outer surface (top or bottom). The top and bottom surfaces are defined according to Fig. 1. In a previous study [1], the helicalhandedness depending on θ was characterized at χ=90°, but the distinction of the outer surface (top or
bottom) was missing. The shape classification in Fig. 2 is also confirmed by the finite element simulation
for the TNE ribbons using a planar LCE with the same composition as a unit element.
Reference[1] Y. Sawa, F. Ye, K. Urayama, T. Takigawa, V. Gimenez-Pinto, R. L. B. Selinger, and J. V Selinger,
PNAS, 108, 6364 (2011).

Fig. 1 Geometry of TNE ribbon specimens

Fig. 2 Shape classification of TNE ribbon.

Mechanoresponsive PDMS
fluorescence in sub-MPa stress

P6

that

reversibly

changes

Hidetsugu Kitakado1 and Shohei Saito1*

1 Graduate School of Science, Kyoto University, Japan* s_saito@kuchem.kyoto-u.ac.jp

PDMS is a silicone elastomer that is widely used in biotechnology and electronics fields
due to its biocompatibility, flexibility, transparency, and easy processability. In this study,
we have developed PDMS elastomers that can quantitatively evaluate weak sub-MPa stressby ratiometric fluorescence analysis. In the PDMS, a flexible fluorescent force probe (FLAP)
has been chemically introduced into cross-linking positions of the polymer chain network.
The FLAP molecule changes the fluorescence spectrum quickly and reversibly by its
conformational conversion, thus FLAP can be used for real-time analysis of nanoscale stressconcentration[1]. Stress-strain curve and viscoelasticity of PDMS with different composition
ratios have been analyzed to reveal the relationship between mechanical properties andfluorescence response. The fluorescence response by compression as well as stretching will
be discussed.

Fig. 1. Force-responsive reversible fluorescence change of the FLAP molecule.
(a)

517

(b)

457

Fig. 2. (a) Fluorescence spectral change and (b) ratiometricfluorescence analysis of the PDMS elastomer during a tensile
test.

Fig. 3. Reversible fluorescence
response of the PDMS elastomer
during stretching and shrinking.

References[1] R. Kotani, S. Yokoyama, S. Nobusue, S. Yamaguchi, A. Osuka, H. Yabu, S. Saito, Nature Commun., inrevision.

P7

Dynamic Control of Array Structure Based on Fe3O4 Magnetic
Nanoparticles by Hybridization with Liquid-Crystalline
Organic Dendron
Takehiro Yachi1, Masaki Matsubara1, 2, Atsushi Muramatsu1, Kiyoshi Kanie1

1 Institute of Multidisciplinary Research for Advanced Materials, Tohoku
University, Japan
2 Department of General Engineering, National Institute of Technology, Sendai
College, Japan* kanie@tohoku.ac.jp
Magnetic nanoparticles (NPs) are attracting special attention because of their unique magnetic properties
different from those of the bulk states. In addition, their magnetic properties are affected by their interactions
dependent on the interparticle distances. Therefore, formation of the array structure based on magnetic NPs
enables us to control their magnetic properties, being still a challenging problem due to strong magnetic
interaction between magnetic NPs in such magnetic NPs-based colloidal crystals. Liquid-crystalline (LC)organic dendron is one of the most representatives to show a thermotropic LC behavior by self-assembling
into columnar and spherical dendrimer-like structures. In our previous studies, we have developed thedendron-modified inorganic NPs to form LC cubic structures by surface modification of NPs with LC
dendrons [1,2]. In the present study, we applied this technique to Fe3O4 magnetic NPs to control the arraystructure based on magnetic NPs. The schematic image of the material design is shown in Fig. 1. A synthetic
procedure for the dendron-modified Fe3O4 NPs is as follows: Firstly, COOH-modified Fe3O4 NPs weresynthesized by a thermal decomposition method
followed by a ligand exchange reaction with aterminal COOH-substituted phosphonic acid. Then,an amidation reaction was carried out between the
COOH group on the surface of Fe3O4 NPs and an
amino group of LC dendrons. Fig. 2 shows TEM
images of COOH- and dendron-modified Fe3O4

Fig. 1 Schematic illustration of dynamic control ofarray structure based on Fe3O4 NPs.

NPs. Since both the particle diameters were
calculated as 6.8 ± 0.6 nm, the size and shape was
scarcely influenced by the reaction. On the other
hand, interparticle distance increased to 12.9 nm
from 8.7 nm and well-ordered hexagonal array wereobserved after the reaction. The self- assemblingproperty was successfully introduced into the Fe3O4
NPs. The self-assembling behavior and the magnetic
property of LC dendron-modified Fe3O4 NPs will be

Fig. 2 TEM images of (a) COOH-modified and (b)dendron-modified Fe3O4 NPs.

discussed.
References[1] K. Kanie, M. Matsubara, X. Zheng, F. Liu, G. Ungar, H. Nakamura, A. Muramatsu, J. Am. Chem. Soc.,
134, 808 (2012).
[2] M. Matsubara, W. Stevenson, J. Yabuki, X. Zeng, H. Dong, A. Muramatsu, G. Ungar, K. Kanie, Chem,
2, 860-876 (2017).

P8

Title ： Synthesis of Polymerizable Tetrabenzocoronene
Mesogen Carrying with Diacetylenic Side Chains
Chun-Jui Chen1*, Huan-Chang Lu1*, Shih-Hsien Yu1, Hsiu-Hui Chen1*,
Yu-Tai Tao2

1 Department of Molecular Science and Engineering, National Taipei University ofTechnology, Taipei 106, Taiwan
2 Institute of Chemistry, Academia Sinica, Taipei, Taiwan 11521, Republic of China

Polymerizable tetrabenzocoronene (TBC) derivatives were designed and synthesized in our work, thestructure is shown as Figure 1. TBC compound have a good electron transport ability caused strong π-πinteraction. All TBCs can be polymerized by UV irradiation and form the homogenous film, which is
proposed to show the greater charge mobility than TBC monomer. Synthetic strategy of TBCs isusing Katz-modified Mallory half-photocyclization method irradiated by 48 W of 365 nm mercury

lamp, using FeCl3 to process the cyclodehydrogenation, and then do esterification withdiacetylenic side chains to obtain final compound. The purity of compounds is investigated by
Nuclear Magnetic Resonance spectroscopy (NMR) and Infrared (IR) spectroscopy. The
characteristics are investigated by differential scanning calorimetry (DSC), X-ray diffraction,
fluorescence spectroscopy, and UV−vis spectroscopy.

Figure 1. The structure of TBC
References[1] Kuo, Y-L.; Tseng, C-Y.; Tseng, C-W.; Chu, K-T.; Liu, Y-C.; Chiang, M-H.; Saeki, A.; Tao, UT.; and Chen, H-H. ACS Appl. Polym. Mater. 2020, 2, 248−255.
[2] Zhang, X.; Jiang, X.; Zhang, K.; Mao, L.; Luo, J.; Chi, C.; Chan, H.S.O.; and Wu, J. J. Org.
Chem. 2010, 75, 8069-8077.

P9

Mechanical Response of Molecular Orientation in Liquid
Crystal Elastomers Controlled by Multi-Layered System
Yudai Fuwa, Kyohei Hisano and Osamu Tsutsumi*

Department of Applied Chemistry, Ritsumeikan University, Japan* tsutsumi@sk.ritsumei.ac.jp

Liquid crystal elastomers (LCEs), in which mesogenic orientation are strongly coupled withpolymer network, have attract much attention to realize stimuli-responsive applications. For example,
the mechanical elongation leads to macroscopic deformation of elastomer in coincidence withmesogenic reorientation and of materials properties. This process is well-known as soft-elastic response.
Typically, the soft-elastic response is very fast when stimulus applied; however, after the stimulus
removal, the macroscopic shape and microscopic orientation exhibits slow recovery due to theviscoelastic behavior based on a molecular structure of CLEs. This means that the limited tunability on
the speed of recovery response has tended to narrow their application range. Very recently, we havefound that a simple materials design concept that is an LCE layered with other films showing desired
mechano-responsive behavior enables to arbitrary tune the speed of recovery response even in the regionof soft-elastic response. This initial finding indicates that microscopic mesogenic orientation is governedby the deformation behavior of other external layers. In this study, we investigated the relationshipbetween the mesogenic reorientation of the inner layer of LCEs and the external other layers underapplied strain. More specifically, we examined the effect of anisotropic deformation of the outer layers
on the three-dimensional mesogenic reorientation behavior of LCEs. To facilely quantify the mesogenic
reorientation with high spatiotemporal resolution, we employed cholesteric liquid crystal medium as aninternal LCE layer. The helically twisted mesogenic orientation in the medium, exhibiting Braggreflection at a certain wavelength matched with the helical pitch, allows us to visualize threedimensional mesogenic reorientation under deformation.
The cholesteric LCEs sandwiched by other layers were fabricated by photopolymerization of
mixtures of a LC monomer, a chiral dopant, a plasticizer, a crosslinker and an initiator in a glass cellattached with the external layers. The multi-layered film exhibited a bright reflection, and the color was
blue-shifted by application of tensile strain. We evaluated the strain in thickness from the reflection
wavelength and investigated the effects of mechanical properties of external layers on the threedimensional mesogenic reorientation behavior.

P10

Two-step fluorescence color change of stress-responsive
polyurethanes that incorporate a flapping molecule
Kensuke Suga1, Takuya Yamakado1, and Shohei Saito1*
1 Graduate School of Science, Kyoto University, Japan* s_saito@kuchem.kyoto-u.ac.jp

We have recently developed flapping molecules, FLAP [1], with various functions andapplications. For example, anthracene-based FLAP works as a ratiometric force probe that shows afluorescence switch at the low threshold (ca. 100 picoNewton) [2]. Relaxed bent conformation of FLAP
emits a blue fluorescence in polymeric environments, while the stressed planar conformation shows agreen fluorescence in stretched polymers. The FLAP force probe reversibly shows the stress-induced
fluorescence change without covalent bond scission, and therefore it realizes quantification of local
stress concentration in entangled polymer chain network before structural damage.
Here we discovered a novel two-step fluorescence color change during the tensile test of FLAPincorporated polymers. A new flapping fluorophore containing phenazine wings (FLAP1) was
chemically doped as a crosslinker of segmented polyurethanes (Figure 1). The fluorescence color
changed from blue to green under lower stress (-12 MPa), and then it further changed to yellow underhigh stress (-57 MPa). Mechanism of the two-step fluorescence change will be discussed (Figure 2).

Figure 1. Chemical structure of the FLAP1-doped segmented polyurethane.

Figure 2. (a) Stress-strain curve of the FLAP1-doped polyurethane. (b) Fluorescence spectral change during thetensile test. (c) Photographs of the stretched specimen showing the two-step fluorescence color change.

References[1] S. Saito et al. (a) J. Am. Chem. Soc. 135 (2013) 8842; (b) Nature Commun. 7 (2016) 12094; (c) J. Mater.
Chem. C 5 (2017) 5248; (d) Angew. Chem. Int. Ed. 59 (2020) 16430.
[2] R. Kotani, S. Yokoyama, S. Nobusue, S. Yamaguchi, A. Osuka, H. Yabu, S. Saito, Nature Commun., inrevision.

P11

Dynamic Coupling in Surfactant Lamellar and Colloid particles
MixturesShingo Yoshioka* and Jun Yamamoto

Faculty of Phisics, Kyoto University of Science, Japan* yoshioka.shingo.44w@st.kyoto-u.ac.jp

Introduction: Water solution of C12E5 forms a lamellar phase in a wide region of concentrations. We
were interested in the dynamic coupling between the undulation fluctuations of lamellae and theBrownian motion of colloidal particles [1]. We investigated the dispersion relations for both modes byusing the dynamic light scattering (DLS). We try to clarify thenature of the dynamic coupling between two motions bychanging the concentration of colloidal particles.
Results: We used of the mixture of the lamellar phase made of
the water solution of C12E5 and water dispersion of colloidal
particles. Lamellar phase consists of the water solution of
C12E5 (φ=6 wt%; inter-membrane distance 62.5nm) andcolloidal particles dispersion (latex beads, Φ=0.15 wt%;
Fig. 1 Autocorrelation function of thediameter 20 nm, negatively charged).
mixture of the lamellar phase andAs shown in Fig.1, two types of relaxation modes were colloidal dispersions. Each line represents
observed simultaneously in the autocorrelation function of the the scattering angle dependences.
mixture. We analyzed the dispersion relation of both fast and slow
modes by changing the scattering angle (Fig.2). Since therelaxation frequency of the fast mode of the mixture (green closed
circles) is very close to that of pure colloid dispersion (blue closed
circles), then fast mode is identified to be Brownian motion ofcolloidal particles. Red circles is the dispersion relation of theundulation fluctuation of the pure lamellar phase. Slow mode canalso be identified to be the undulation fluctuation of the lamellarof mixture. We found that the undulation fluctuation of thelamellar should be slowing down due to the existence of the Fig. 2. Dispersion relation of purecolloidal dispersion, pure lamellar
colloid particles. Finally, we studied effect of concentration of phase, and the mixture.
colloids on the undulation fluctuations of the lamellar (Fig. 3). It
should be noted that the undulation fluctuations of the lamellar isslowing with increase of Φ.
Conclusion: The deceleration of the undulation fluctuations in the
mixture should be caused by decrease of the layer compression
modulus. Namely, the presence of colloidal particles between
membranes prevents direct collisions between adjacent membranes
and weakens the steric interaction between them.
Fig.
3.
ConcentrationΦ
References
dependence of diffusion constants
for fast and slow modes.
[1]J. Yamamoto and H. TANAKA. Nature Materials, 4 (2005) 15.

P12

Columnar Nematic Liquid Crystal of Monodisperse Titanate
Nanosheets Exchanged with Dodecyltrimethylammonium
Yuji Nakashima1, Momoka Miyoshi1, Riki Kato1 , and Nobuyoshi
Miyamoto1*
1 Graduate School of Engineering, Fukuoka Institute of Technology, Japan* miyamoto@fit.ac.jp

Inorganic nanosheets have been highlighted as new-type colloidal liquid crystal (LC) systems since
their rediscovery1 and have been applied for anisotropic and tough gel materials suitable for artificial
muscles.2 However, it was difficult to precisely optimize the nanosheet LC property due to thedifficulty in controlling the particle size and the lack of structural designability. In this situation, we
recently found that monodisperse nanosheets synthesized by bottom-up method2 form a string-likecolumns of stacked nanosheets and columnar nematic liquid crystal phase. In this study, we
synthesizedcolumnsofstackednanosheetstabilizedbylong-chain

alkylammonium(decyltrimethylammonium chloride [C10TMACl]) with the aim of using them as actuator devices.
The wide angle X-ray scattering (WAXS) results of thecolumnsofstackedtitanatenanosheetswithtetramethylammonium (TMA) as the interlayer cation are
shown in Fig. 1a. A sharp peak at d001=1.7 nm is observed,
indicating that the nanosheets are stacked with a period of 1.7
nm. Since the thickness of the titanate nanosheets is 0.75 nm,
the interlayer distance is calculated as 0.95 nm that matches
the size of hydrate TMA. By the addition C10TMA (8.0 times
amount of the cation exchange capacity [CEC] of the titanate
nanosheets) (Fig. 1d), d001 increases to 2.9 nm (interlayer
distance of 2.15 nm). Considering that the length of the
all-trans C10TMA+ is about 1.54 nm, the C10TMA+ isintercalated as a bilayer structure with a 44° tilt in the+interlayer. As the amount of C10TMA increases (Fig.1b, c, d),the full width at half maximum of the d001 peak decreases,

Fig. 1 WAXS patters of the nanosheets
added with C10TMACl. The added
amount is (a) 0, (b) 4, (c) 6, and (d) 8times of the CEC of the nanosheets.

+

indicating the amount of intercalated C10TMA increases.
When the samples added with 8 times CEC of C10TMA was observed with polarized optical
microscope, interference colors due to birefringence. Based on these results, we conclude thatcolumnar nematic LC of stacked nanosheets with interlayer C10TMA+ are formed.
References[1] N. Miyamoto, T. Nakato, Adv. Mater. 2002, 14, 1267-1270.
[2] T. Inadomi, et al., Macromol. Rapid. Commum., 2014, 35, 1741-1746[3] E. L. Tae, et al., J. Am. Chem. Soc., 2008, 130, 6534-6543

P13

Photoreduction Synthesis of Gold Nanosheet in Hyperswollen
Lyotropic Lamellar Phase
Koki Sasaki*, Tsuyoshi Okue, Takuto Nakai, Yoshiaki Uchida, andNorikazu Nishiyama
Graduate School of Engineering Science, Osaka University, Japan* kokisasaki@cheng.es.osaka-u.ac.jp

Nanosheets (NSs) synthesis in lyotropic lamellar phases have attracted attentions because of their highversatility. We have developed the synthesis method of NSs inside bilayers of hyperswollen lyotropic
lamellar phases (HL phases), whose bilayers with several nm thickness are separated from each otherby several hundred nm [1]. We can use them as independent two-dimensional (2-D) reaction fields.
These reaction fields can prevent NSs from aggregation because of the intervals. We named this
synthesis method ‘two-dimensional reactor in amphiphilic phase (TRAP) method.’ We havesuccessfully synthesized hydrophobic NSs inside the hydrophobic TRAPs in aqueous amphiphilicsolutions [2]. We expected that the unexplored hydrophilic TRAPs enable us to synthesize hydrophilic
NSs. As the next target of the NSs synthesis, gold is the suitable because it is synthesized byphotoreduction in the hydrophilic reaction field. Gold has face centered cubic lattice, whose growth isisotropic. Therefore, the synthesis of the gold NSs (AuNSs) acts as a test of new TRAP method
applicable to other materials like other crystalline materials with cubic lattices, organometallic
compounds, and amorphous materials.
Here, we show the facile synthesis of uniformly thin AuNSs in a
sodium 4-octylbenzensulfonete solution by irradiation with UV light.
The horizontal width and thickness of the obtained AuNSs measured
by atomic force microscopy (AFM) are 1500 ± 560 nm and 2.18 ± 0.50
nm, respectively, as shown in Fig. 1. The full width at half maximum(FWHM) of each of the X‐ray diffraction (XRD) peaks of the AuNSs
was broader than that of the Au fine particles synthesized without

Fig. 1 AFM image andTRAPs. The Williamson-Hall plots indicate that the crystallite size ofcross-section analysis

the AuNSs is smaller than that of Au fine particles. Moreover, theof one of the AuNSs.

selected area electron diffraction (SAED) pattern measured by transmission electron microscope (TEM)
also indicates that the AuNSs are polycrystals consisting of small crystals; the SAED pattern showsconcentric circles. These results indicate that the uniformly nanosized Au particles are likely to fuselaterally in the confined thin 2-D reaction field in the HL phase, and they only grow laterally, as shownin Fig.1. The hydrophilic TRAP method could be applied to other hydrophilic NSs because theprecursors are accumulated due to rather physical confinement than chemical specificity.
References[1] F. C. Larche, et al., Phys. Rev. Lett., 56 (1986) 1700–1703.
[2] Y. Uchida, et al., J. Am. Chem. Soc., 4 (2016) 1103–1105.

P14

Fabrication of nematic liquid-crystal necklaces and their
physical properties
Yoshiko Takenaka1*, Miha Škarabot2, and Igor Muševič2

1 Research Institute for Sustainable Chemistry, National Institute of Advanced
Industrial Science and Technology (AIST), Japan.
2 Jožef Stefan Institute, 1000 Ljubljana, Slovenia.
* takenaka.yoshiko@aist.go.jp

Various kinds of self-assembly of liquid crystals, i.e., nematic droplet, nematic shell, cholesteric shelland liquid crystal fiber, are abundantly studied for the applications to a micro-laser, a micro opticalresonator, and so on. Among these self-assemblies, nematic droplets demonstrate Whispering Gallery
Mode (WGM) resonance, which is useful for a micro optical resonator [1]. In this study, we succeeded
to fabricate the connected nematic liquid-crystal droplets with tethers, called as a liquid crystal
necklace [2].
Liquid crystal necklace was made with a microfluidics device [3]. 5 % aqueous solution of polyvinyl
alcohol (PVP 72000, Merck) and 4-cyano-4’-Pentylbiphenyl (5CB; TCI) were used as continuous anddispersed phases, respectively. Necklace structures with various droplet diameters (ca. 20 – 300 m)
were formed by tuning the capillary diameter of a microfluidics device or flow rates of both liquids.
The tether part was so thin that it could not be observed by an optical microscopy, however we could
confirm the connection between tethers and droplets by means of the laser tweezers. The necklace
structure was not broken by the nematic-isotropic phase transition induced by the increase in thetemperature. The structure was also preserved by the change in the molecular alignment of liquid
crystals inside the droplet from parallel to homeotropic alignment.
The detailed structure and the physical properties of tethers were investigated. By the observation ofa confocal microscopy and a polarization microscopy, it was revealed that tethers are made of thecomplex of PVP and 5CB, and in addition, both of them align along the long axis of a tether. The
elastic constant of the tether was determined by using laser tweezers to stretch the tether. It is about 8
kPa, and thus it is similar to the elastic constant of a PVA hydrogel [4].
The WGM circulating inside individual droplets in the necklace structure were also observed.
However, no light could be seen being guided through the tethers. For the light transport to tethers, thestabilization of tethers and usage of chiral nematic liquid crystal will be helpful.

References[1] M. Humar, M. Ravnik, S. Pajk, and I. Muševič, Nat. Photonics 3 (2009) 595.
[2] Y. Takenaka, M. Škarabot and I. Muševič, Langmuir 36 (2020) 3234.
[3] A. S. Utada, E. Lorenceau, D. R. Link, P. D. Kaplan, H. A. Stone and D. A. Weitz, Science 308 (2005)
537.
[4] N. Yang, J. R. Bruyn and J. L. Hutter, Physics in Canada 64 (2008) 141.

P15

Iridescent Colors in Aqueous Solutions of Chromonic Disodium
Cromoglycate Doped with Chiral Additives
Khoa V. Le1*, Hiroki Shibakura1, Tatsuya Shirai1, Yumiko Naka1, Takeo
Sasaki1, Min Shuai2, and Noel A. Clark2
1 Department of Chemistry, Faculty of Science, Tokyo University of Science2 Department of Physics, University of Colorado, Boulder, Colorado, USA* khoa@rs.tus.ac.jp

Understanding the mechanism underlying the self-organization of chromonic molecules into lyotropic
liquid crystals (LCLCs) has drawn much attention in recent years, as it may provide more insights into
the research for biological and medical applications [1]. This is probably because of their similarity to
DNA liquid crystals. This report investigated the phase behavior and the helical twisting powers ofchiral solutions of disodium cromoglycate (DSCG) in water [2-3]. The addition of water-soluble chiraldopants to the nematic phase of DSCG readily turned it into the cholesteric phase. The cholestericpitch was measured by Grandjean–Cano wedge cell method. The microscopic structure wascharacterized by X-ray diffraction and freeze-fracture transmission electron microscopy (FF-TEM). In
general, the twisting power is weak, and the shortest pitch (ca. 2.9 m) was obtained using trans-4hydroxy-L-proline. However, one can still observe the iridescent colors of some of the cholestericsamples at certain viewing angles [4].

Fig. 1 Iridescent colors due to the selective reflections in an unaligned sample ofdisodium cromoglycate in water doped with trans-4-hydroxy-L-proline 26 wt%.

References[1] J. Lydon, Liq. Cryst. 38 (2011) 1663.
[2] H. Lee and M. M. Labes, Mol. Cryst. Liq. Cryst. 108 (1984) 125.
[3] T. Ogolla, S. B. Nashed and P. J. Collings, Liq. Cryst. 44 (2017) 1968.
[4] T. Shirai, M. Shuai, K. Nakamura, A. Yamaguchi, Y. Naka, T. Sasaki, N. A. Clark and K. V. Le, Soft
Matter 14 (2018) 1511.

P18

High-performance liquid-crystal-loaded terahertz wave variable
phase shifter with non-radiative dielectric waveguide structure
Trong Nghia Lang, Yo Inoue, and Hiroshi Moritake*
Department of Electronical and Electronic Engineering,
National Defense Academy, Japan* moritake@nda.ac.jp

To realize ultra high-speed terahertz (THz) wireless communication, antennas that support
transmission/ reception in multiple directions become indispensable, and high-performance phaseshifters are increasingly required. Liquid-crystals (LCs), which have excellent characteristics such aslarge anisotropy even in the THz region and good response to an external electric field, are expected for
THz applications in recent years. In the region of light, most experiments allow light waves to passthrough a free space before arriving at the device. On the other hand, unlike light, the THz waves havea longer wavelength of about 1 mm, and when they are radiated into free space, a large amount of leakywave and diffraction wave arises. In previous study, a transmission-type THz wave phase shifter has
been reported. In this case, the transmission loss is enormous at about -15 dB, and there is an unsolved
problem of satisfying both large phase change and fast response [1]. Furthermore, we have reported atransmission-line-type THz wave phase shifter using a non-radiative dielectric (NRD) waveguide[2]. In
this study, we propose a high-performance LC-load THz wave variable phase shifter with the NRD
waveguide structure, which simultaneously performs short response times and continuous phase control.
Fig. 1 shows the cross-section diagram of the device and a simulation result of propagating electricfield distribution at 350 GHz. In this study, we used high-density polyethylene (HDPE) as low loss
dielectric material for the transmission line and PTFE sheet as spacers for the LC cell. With simulation
results, we can see that the THz wave is radiated from a rectangular waveguide (WR2.2) and completely
confined in the dielectric waveguide without leaky-wave and diffraction wave at the air part or PTFE
spacers. Moreover, as shown in Fig. 2, the THz wave variable phase shifter having response times ofabout 1 s to several ms and phase change near 270 degrees is realized. Detail will be debated on site.

Fig. 1 Cross-section diagram of the device and simulation
result of electric field distribution at 350 GHz

Fig. 2 Response characteristics of the phaseshifter at 350 GHz

References[1] Q. T. Duong, H. Kobayashi, Y. Inoue, and H. Moritake, Jpn. J. Appl. Phys. 56 (2017) 061701.
[2] T. N. Lang, Y. Inoue and H. Moritake, Crystals 10 (2020) 307.

P19

Emitting Color-switching in TN display using transparent UV
range polarizer
Shota Harano1 and Rumiko Yamaguchi2*

1 Electrical and Electronic Engineering Course, Akita University, Japan
2 Graduate School of Engineering Science, Cooperative Major in Life Cycle
Design Engineering, Akita University, Japan* yrumiko@gipc.akita-u.ac.jp

A conventional liquid crystal display (LCD) is non-emissive type and polarizer films with thetransparence of about 45% or less. Recently, Mochzuki and Morita have proposed a novel transparent
emissive LCD which was fabricated by using a UV range polarizer, a TN liquid crystal cell and apolarized blue light emitting film [1]. Both the polarizer and the emitting film have high transmittanceover 85% in the visible region, therefore the LCD shows a blue emission on the transparent background.
In this study, we have proposed the emissive color switching LCD using the polarizer and the emitting
film.
Figure 1 shows a schematic model of the emissive LCD and a principle of the emission color switch.
A small amount of fluorescent dichroic dye is dissolved in the TN cell. In the off-state, the polarization
direction and the absorption axis of the dye in the TN cell is parallel and bright emission from the LC
cell can be obtained. Moreover, the polarization direction of the transmitted UV light is rotated at 90
and is not absorbed in the external blue emitting film, that is “LC emitting state”. In the on-state, theemission light intensity decreases and the UV light passes through without the polarization rotation, thenthe external emission film absolves the UV light and emits a bright light, that is “emitting film excitedstate”. We used Coumarin 6 as a guest of fluorescent dichroic dye [2]. When without the UV irradiation,
the LCD is slightly yellowish because of the absorption of Coumarin 6 in visible region. Using a UVLED ( max =365 nm), the emission spectrum was measured and switching property is shown in Fig. 2.

The peak wavelength changed from 525 nm of Coumarin 6 to 440 nm of the emitting film and theemission color was successfully switched from green to blue. Dichroic ratio (DR) of Coumarin 6 in the

UV rangepolarizer

TN cellemitting
film

Off-state
unpolarized
UV light

absorption axis

On-state

Intensity (a. u.)

LC is about 6 and higher DR might improve the color difference more.
On state
Off state
400

Fig.1 Principle of emission color
switching

500

600

Wavelength (nm)700

Fig.2 Emission spectra in off- and on-state of
LCD.

References[1] N. Mochizuki, R. Morita: Development of Transparent Emissive LCD Using Novel Polarized LightEmitting Film, JSID Vol.26 pp.670-674 (2017)[2] R. Yamaguchi, J. Kishida, and S. Sato: Multicolor Switching Properties in Fluorescent Liquid Crystal
Displays, Jpn. J. Appl. Phys. Vol.39 pp. 5235-5238 (2000).

P20

Continuous rotation of a cholesteric liquid crystalline droplet
by a circularly polarized optical tweezers
Keita Saito*, Yuta Tamura, and Yasuyuki Kimura
Department of Physics, Kyushu University, Japan* saito.keita.599@s.kyushu-u.ac.jp

The manipulation of micrometer-scaled objects is important for utilizing them as micromechanicaldevices and to elucidate their microscopic properties. Optical manipulation methods including opticaltweezers have been intensively studied and one can translate and rotate micro-objects with accuracyof sub-microns. Not only the manipulation of optically isotropic objects but also that of opticallyanisotropic ones has been studied. In case of birefringent objects, one can rotate them via linear andcircularly polarized light [1]. One of typical optical birefringent spherical objects is a liquid crystalline(LC) droplet. The continuous spinning of a nematic LC droplet has been reported under the irradiationof focused circularly polarized laser beam [2,3]. The direction of the rotation is controlled by that of acircular polarization of the beam.
In this research, we studied the opto-mechanical response of a cholesteric liquid crystalline (ChLC)
droplet to a circularly polarized optical tweezers. The micrometer-sized droplets were prepared byvigorous mixing of a nematic liquid crystal and chiral dopant R-811 in water. The ChLC droplets withvarious sizes (diameter d) and helical pitch p (strength of chirality) were trapped by an optical tweezers.
Their response was studied by varying the direction of circularly polarized light (CPL). Although thealignment of LC molecule within a droplet depends on the relative ratio d /p [4], the optically induced
rotation is asymmetric to the direction of CPL irrespective to their inner molecular alignment. Thisasymmetric response enables us to detect the chirality of droplets and separate them within amicrofluidic device.
For a droplets of d/p < 1, a twisted bipolar droplet [4] exhibits asymmetric response: the rotation
appears only for a right-circularly PL (RCPL). For a droplet of d/p > 1, a radial spherical droplet [4] also
rotates only by RCPL. In the case of d/p ~ 1, the rotation is induced by both RCPL and LCPL. Its
direction of the rotation is simply determined by the chirality of ChLC in this case. The intermittent
rotation is also observed for a linearly PL, which has already been reported by Yang et al. [5]This work is supported by JSPS KAKENHI (JP20H02947).
References[1] M. E. J. Friese, T. A. Nieminen, N. R. Heckenberg and H. R. Rubinsztein-Dunlop, Nature 394 (1998) 348.
[2] S. Juodkazis, M. Shikata, T. Takahashi, S. Matsuo, and H. Misawa, Appl. Phys. Lett. 74 (1999) 3627.
[3] T. A. Wood, H. F. Gleeson, M. R. Dickinson, and A. J. Wright, Appl. Phys. Lett. 84 (2004) 4292.
[4] F. Xu, and P. P. Crooker, Phys. Rev. E 56 (1997) 6853.
[5] Y. Yang, P. D. Brimicombe, N. W. Roberts, M. R. Dickinson, M. Osipov, and H. F. Gleeson, Optics
Express 16 (2008) 6877.

P21

Specific molecular orientation and structure induction at theinterface between nematic liquid crystal and azobenzene
polymer film
Chikara Kawakami1, Mitsuo Hara1, Shusaku Nagano2,Takahiro Seki1*
1 Graduate School of Engineering, Nagoya University, Japan
2 College of Science, Rikkyo University, Japan* tseki@chembio.nagoya-u.ac.jp

A monolayer of azobenzene compound or polymer on
the surface can induce reversible alignment switching of
nematic liquid crystals (NLCs) between homeotropic
and planar modes upon visible/UV light irradiation,
which is called the command surface [1]. To gain
insight into the molecular process at the interface,
Ubukata et al. investigated model hybrid LB films
composed of 5CB and an Az polymer [2]. On the otherFigure 1. Structures of P5Az10MA (a)and 5CB(b)hand, we recently fabricated a setup for the in-situ
measurement of grazing incident small angle X-ray
scattering (GI-SAXS) that can evaluate the structure at
the substrate surface. In the present work, this X-ray
analysis tool is applied to evaluate the structure at theinterface between NLC and alignment layer.
In this study, liquid crystal molecules (5CB) wereplaced on an alignment film of side-chain azobenzene
polymer (P5Az10MA) (Figure 1), and GI-SAXS
measurements were performed to evaluate the structurefrom the vicinity of the interface to the bulk (Figure 2).

Figure 2. The glass cell used in
GI-SAXS measurement and the imageof interface structure formed by
P5Az10MA and 5CB.

For the structural analysis, we designed a 35-µm thick glass cell (Fig. 2). A P5Az10MA spin-coatedfilm (thickness: 60 nm) alone gave the out-of-plane peaks, indicating a smectic layer formation in thein-plane direction. Interestingly, after 5CB is injected, the out-of-plane peaks disappeared and thepeaks up to the third order appeared in the in-plane direction (Fig. 2). This result indicates that, upon
5CB injection into the homeotropically aligned P5Az10MA, an orientation inversion to the in-plane
direction accompanied by a highly ordered smectic hybrid layer formation of 5CB and P5Az10MA
occurred at the interface. The details will be reported at the presentation.
References[1] K. Ichimura et al., Langmuir, 4, 1214 (1988); T. Seki et al., Langmuir, 9, 211 (1993).
[2] T. Ubukata et al., J. Phys. Chem., 104, 4141 (2000); T. Ubukata et al., J. Phys. Chem. 104, 4148 (2000).

P22

Ultrafast time-resolved electron diffraction with double-pulseexcitation applied to the light-melt adhesive based on a flapping
triphenylene liquid crystal
Yuri Saida1, Tomoaki Konishi2, Ryuma Sato3, Yumi Nakaike2, Wataru
Yajima4, Ryo Shikata4, Mitsuo Hara5, Shohei Saito2, and Masaki Hada3,6*

1 College of Engineering Science, University of Tsukuba, Japan
2 Graduate School of Science, Kyoto University, Japan
3Cellular and Molecular Biotechnology Research Institute, National Institute ofAdvanced Industrial Science and Technology (AIST), Japan
4 Graduate School of Science and Technology, University of Tsukuba, Japan
5 Graduate School of Engineering, Nagoya University, Japan
6 Tsukuba Research Center for Energy Material Science (TREMS), University of Tsukuba, Japan* hada.masaki.fm@u.tsukuba.ac.jp
We performed ultrafast time-resolved electron diffraction measurements with single-pulse-excitationand double-pulse-excitation to investigate the mechanism of the photoinduced melting phenomena of
the light-melt adhesive, which is composed of a flapping triphenylene liquid crystal (TP-FLAP).
Ultrafasttime-resolved

electrondiffraction

measurements enable us to directly monitor themolecular-levelstructuraldynamics

underphotoexcitation on the femto-to-picosecond
timescales [1]. The method with single-pulseexcitation monitors the photoinduced event
starting from the ground state (with all molecules
taking a bent from), which does not necessarily
represent the photoinduced behavior of the TPFLAP molecules under continuous irradiation. In
this study, we compared the time-evolution of thedifferential electron diffraction patterns from themolecules excited by single near-ultraviolet(UV) pulse and double near-UV pulses. Note thattime-resolved electron diffraction measurementswith double-pulse-excitation can monitor thephotoinduced event starting from the excitedstate (with some excited molecules taking aplanar form). Consideration of these excitation
conditions leads to further understanding of thephotoinduced melting behavior of the TP-FLAP
liquid crystal.

Fig. 1 TP-FLAP molecule shows an ultrafast
bent-to-planar conformational change in the
excited state (top). In the columnar packing
structure, a fraction of the molecules areplanarized by a single pulsed near-UV
photoexcitation,
which
modulatesthedifferential electron diffraction patterns(bottom).

[1] M. Hada, S. Saito et al., J. Am. Chem. Soc. 2017 139, 15792-15800.

P23

Development of a photoreversible adhesive with two adhesion
states using poly(methyl methacrylate) containing anazobenzene liquid-crystal plasticizer showing smectic E phase
Mioka Koike1,2, Miho Aizawa3, Hiroyuki Minamikawa3, Atsushi Shishido1, andTakahiro Yamamoto3*
1 Laboratory for Chemistry and Life Science, Institute of Innovative Research,
Tokyo Institute of Technology, Japan
2 Department of Chemical Science and Engineering, School of Materials andChemical Technology, Tokyo Institute of Technology, Japan
3 Research Institute for Sustainable Chemistry, National Institute of Advanced
Industrial Science and Technology, Japan* takahiro.yamamoto@aist.go.jp

We investigated the photoplasticization behavior and photoinduced adhesion properties of poly(methyl
methacrylate) mixed with azobenzene liquid-crystal plasticizers exhibiting different phase structures,i.e., nematic, smectic E, and crystalline phases. It was found that photoplasticization, which is thephotoinduced reduction of glass transition temperature and hardness of polymers,1,2 could be
repeatedly induced by alternate irradiation with ultra-violet (UV) and visible light, regardless of thephase structures of the photoresponsive plasticizers. Upon photoplasticization under UV-lightirradiation, all samples exhibited the first adhesion state with weak adhesion strength, namely apressure sensitive adhesion (PSA) state. Upon irradiation of the photoplasticized samples with visible
light, the samples exhibited a second adhesion state by recovering their elastic moduli to the initiallevels.

The adhesion strength of the samples in the second adhesion state was significantly

influenced by the phase structures of the photoresponsive plasticizers. When a photoresponsive
plasticizer exhibited the smectic E phase, which is a highly ordered liquid crystalline phase, theadhesion strength was remarkably larger than that of the case using the plasticizers showing nematicand crystalline phases. This result was reasonably explained in terms of the suppressed bleed-out ofthe photoresponsive plasticizers from the polymer, and the good mechanical properties of the sample
stemming from the characteristics of the smectic E phase. Through the reversibility of aphotoplasticization process, we achieved a photoinduced reduction of the adhesion strength by UV
irradiation of the samples in the second adhesion state. Thus, a photoreversible adhesive with two
adhesion states could be developed by the photoplasticization of poly(methyl methacrylate) containing
an azobenzene liquid-crystal plasticizer showing the smectic E phase.

References[1] T. Yamamoto, R. Hasegawa, Y. Kawata, H. Kihara, N. Naga, Chem. Lett. 47 (2018) 272.
[2] M. Koike, M. Aizawa, N. Akamatsu, A. Shishido, Y. Matsuzawa, T. Yamamoto, Bull. Chem. Soc. Jpn.
93 (2020) 1588.

P24

Precision polymerization of a degradable block copolymer
containing a nematic liquid-crystalline polymer block
Daisuke Taguchi1,2, Atsushi Shishido1,2*, Shoichi Kubo1,2*

1 Laboratory for Chemistry and Life Science, Institute of Innovative Research,
Tokyo Institute of Technology, Japan
2 Department of Chemical Science and Engineering, School of Materials andChemical Technology, Tokyo Institute of Technology, Japan*ashishid@res.titech.ac.jp , kubo@res.titech.ac.jp

Block copolymers have attracted great attention as nanotamplates by using sub-100 nm structures
formed by microphase separation. It is necessary to control the alignment of microphase-separated
structures to obtain desired functions. Directed self-assembly of block copolymers have been developed
to obtain well aligned nanostructures along physical or chemical guide patterns [1,2]. We have recently
proposed a simple method for unidirectionally aligning microphase-separated structures simply byintroducing a nematic liquid-crystalline polymer block, where the molecular alignment of liquid crystals
induces the aligned nanostructures without fine guide patterns [3]. In this study, we designed a block
copolymer consisting of degradable polymer and nematic liquid-crystalline polymer blocks towards
developing hollow nanotemplates. We present the synthesis of the block copolymer and evaluation of
their fundamental properties.
Polylactic acid (PLA) was selected as a degradable polymer. Polymethacrylate having a phenyl
benzoate moiety as a side-chain mesogen, PMA(4OPB), was used as a nematic LC polymer. A block
copolymer PLA-b-PMA(4OPB) was synthesized by atom transfer radical polymerization (ATRP) using
a PLA macroinitiator and a methacrylate monomer. A homopolymer PMA(4OPB) was also synthesized
by ATRP for comparison. Gel permeation chromatography analysis indicated that PLA-b-PMA(4OPB)
and PMA(4OPB) with narrow molecular weight distributions were successfully obtained. The
homopolymer PMA(4OPB) exhibited a nematic phase according to differential scanning calorimetry
and polarized optical microscopy. The block copolymer PLA-b-PMA(4OPB) also showed LC properties
similar to the homopolymer. The degradation behavior of the polymers was investigated by immersing
polymer films in a solution of trifluoroacetic acid and subsequently monitoring the changes in themolecular weights. PLA was completely degraded, while PMA(4OPB) almost maintained the molecularweight. Furthermore, the molecular weight of PLA-b-PMA(4OPB) was decreased. These results suggestthat the PLA block in the block copolymer was selectively degraded.
References[1] D. Sundrani, S. B. Darling, and S. J. Sibener, Langmuir 20 (2004) 5091.
[2] E. W. Edwards, P. F. Nealey, et al., Macromolecules 40 (2007) 90.
[3] S. Kubo, M. Nakagawa, et al., Jpn. J. Appl. Phys. 53 (2014) 06JC04.

P25

Two-dimensional molecular orientation directed by scanningwave photopolymerization with digital light processor
Hirona Nakamura1,2, Yoshiaki Kobayashi1,2, Megumi Ota1, Miho Aizawa3,
Shoichi Kubo1,2, Atsushi Shishido1,2*

1 Laboratory for Chemistry and Life Science, Institute of Innovative Research,
Tokyo Institute of Technology, Japan
2 Department of Chemical Science and Engineering, School of Materials andChemical Technology, Tokyo Institute of Technology, Japan
3 Research Institute for Sustainable Chemistry, National Institute of Advanced
Industrial Science and Technology, Japan*ashishid@res.titech.ac.jp

The key for designing high-performance optical devices is the fine and precise control of molecularorientation in liquid-crystalline (LC) materials. In particular, cycloidal molecular orientation in the LC
films enables the fabrication of diffractive optical elements [1]. So far, cycloidal patterns are generally
induced by the polarization holographic technique based on photoalignment processes using theinterference of orthogonally polarized beams [2]. However, this technique has challenges such as low
processability, necessity of polarized laser beams, and difficulty of large-area patterning. Recently, we
have developed a novel method for molecular orientation, termed scanning wave photopolymerization(SWaP)[3,4].

This

methodutilizes

molecular

diffusion

triggeredbyspatiotemporalphotopolymerization, and thus allows us to direct large-area and two-dimensional (2D) molecularorientation without polarized light. In this study, we present the fabrication of LC polymer films with
2D patterns by SWaP with a digital light processor and investigate the optical property of the resultant
films.
As a photopolymerizable sample,
a mixture of an acrylate monomer
A6CB, a crosslinker HDDMA, and aphotoinitiator Irgacure 651 was used

O

O
O

O

CN
O

6

O

O

A6CB

O

O

HDDMA

O

Irgacure 651

Fig. 1 Chemical structures of compounds used for(Fig. 1). The glass cell was preparedphotopolymerization.

by adhering a pair of ultrasonically cleaned glass substrates with 2-µm-thick silica spacers. The sample
mixture was injected into the glass cell and irradiated with UV light by scanning the rod-shape patterns
by digital light processor to carry out SWaP. The polarized optical microscopy revealed the cycloidal
molecular orientation was induced in the LC films. Moreover, the LC film with the cycloidal orientation
exhibited selective diffraction of circularly polarized light.
References[1] S. R. Nersisyan, N. V. Tabiryan, D. M. Steeves, and B. R. Kimball, Opt. Photon. News 21 (2010) 40.
[2] L. Nikolova and P. S. Ramanujam, Polarization Holography, Cambridge University Press, Cambridge(2009).
[3] K. Hisano, M. Aizawa, M. Ishizu, Y. Kurata, W. Nakano, N. Akamatsu, C. J. Barrett, and A. Shishido,
Sci. Adv. 3 (2017) e1701610.
[4] K. Hisano, M. Ota, M. Aizawa, N. Akamatsu, C. J. Barrett, and A. Shishido, J. Opt. Soc. Am. B 36 (2019)
D112.

P26

Patterning Topological Defects in Nematic Liquid Crystals
Using Area-Selective Surface Modification
Ryota Mikami1*, Takuho Kikkawa1, Yuji Sasaki1, and Hiroshi Orihara1

1 Division of Applied Physics, Faculty of Engineering, Hokkaido University,Japan* mikami.ryota.s6@elms.hokudai.ac.jp

The control of the director field is crucial for liquid-crystal-based optical applications. Utilization of
spontaneous pattern formation is an interesting approach, while it is usually difficult to expand theuniform domain in the macroscopic scale. In this regard, it is expected that the assistance of surface
fabrication is useful for producing highly self-organized patterns. [1] In this study, we explore an
efficient approach for controlling self-organized pattern formation of topological defects in nematic
liquid crystals (NLCs). A typical result is shown in Fig. 1. By selectively modifying the surface, we
prepare two homeotropic regions with different anchoring strength which are also capable of generating
a square array of topological defects. (Fig. 1A) Here, a standard transmission electron microscopy(TEM) grid is tested as a mask in modifying the surface. The NLC used is MBBA. Under no electricalvoltage, the whole area shows a homeotropic alignment. (Fig. 1B) On the other hand, when the electricfield is increased, we observe square arrays of umbilical defects. We obtain a quite uniform domain in
the area where the surface is modified, while the outside area shows multiple domains. (Fig. 1C) Since
the diameter of TEM grids is around 3 mm, it provides a sufficiently large area for optical experiments.
In this presentation, we show experimental results which are obtained by changing the sample thickness
and the size of TEM grids.

Fig. 1 (A) Schematic illustration of surface modification. (B) A homeotropic
texture under no electric field (C) A highly self-organized pattern of defects
arrays induced by an electric field obtained by the assist of surface
modification. Scale bar, 1 mm.
References[1] M. Kim and F. Serra, Advanced Optical Materials 8 (2020) 1900991.

P27

Enhanced electric field tunability and thermal stability ofphotonic crystal fibers filled with gold nanoparticles-doped
cubic blue phases liquid crystals
Kamil Orzechowski*1, Wiktor Lewandowski2, Olga Strzeżysz3, Martyna
Tupikowska2, Tomasz R. Woliński1
1 Faculty of Physics, Warsaw University of Technology, Warsaw, Poland
2 Faculty of Chemistry, University of Warsaw, Warsaw, Poland
3 Institute of Chemistry, Military University of Technology, Warsaw, Poland* kamil.orzechowski@pw.edu.pl

Blue phase liquid crystals (BPLCs) are interesting materials that create unique self-assembling cubic
structures in two phases BP I and BP II or occur as an isotropic-like ‘fog phase’ BP III. BPLCs exist
between cholesteric and isotropic phases in a very narrow range of temperatures (~0.1-5.0 K) and arecharacterized by outstanding properties such as 3D Bragg reflections, optical isotropy, andpolarization insensitivity in a macroscopic scale for the wavelengths outside their resonance bands [1,2]. Currently, BPLCs belong to the most promising materials for perspective applications not only infast-switching LC displays, but also in advanced photonic structures such as photonic crystal fibers(PCFs) [3, 4]. However, so far only a few papers have focused on studies in the latter field,
considering mainly characterization of spectral properties of BPLC-filled PCFs. Moreover, thesecomplex photonic structures still have significant limitations in optical communication such as not fastenough response times as well a necessity to use high driving voltage due to a relatively large cladding
diameter of the PCF.
This work expands our preliminary observations by carrying out studies of optical properties of gold
nanoparticles-doped cubic BPLCs infiltrating PCFs. It has been shown that the examined photonic
system can provide promising tunable properties, enhancing the external electric field sensitivity andtemperature stability. This is due to the presence of gold nanoparticles with an appropriate organic
coating in a liquid crystal matrix. The presented results indicate lowering the threshold voltage andincreasing the operating temperature range of the investigated photonic system. Furthermore, it turns
out that a control of the light intensity for specific wavelengths can be obtained. Moreover, a range of
wavelengths corresponding to low transmission (photonic bandgap) depends on the input lightpolarization and can be controlled by an external electric field.

References[1] H. Yoshida et al., Phys. Rev. E 94, 042703 (2016).
[2] K. Orzechowski et al., Opt. Mater. 69, 259–264 (2017).
[3] C.-H. Lee et al., Appl. Opt. 52, 4849–4853 (2013).
[4] K. Orzechowski et al., Opt. Express 27(10), 14270-14282 (2019).

P28

Observation of three-dimensional structure in electrohydrodynamic convective patterns of cholesteric liquid crystals
by fluorescent confocal microscopy
Kentaro Tanaka*, Takahiro Takada, and Yasuyuki Kimura
Department of Physics, Kyushu University, Japan*tanaka.kentaro.497@s.kyushu-u.ac.jp

Electrohydrodynamic convective (EHC) patterns in nematic liquid crystal (NLC) have been studied asa typical non-equilibrium open system. Since cholesteric liquid crystal (ChLC) exhibit helicalstructure due to chirality, the convective patterns in ChLC are expected to be more complex than thosein NLC. Various kinds of characteristic patterns have been reported: stripe, square lattice, eddy
ones1,2). The ratio of a helical pitch p to the cell thickness d is the parameter which governs the type ofthe observed patterns. A pattern which appears first depends on p/d: a stripe pattern appears first forsmall value of p/d, and a square lattice pattern for large p/d.
EHC patterns are usually observed under a polarizing microscope. However, the obtained images
are averaged ones of the three-dimensional pattern along vertical direction. Recently, fluorescentconfocal polarizing microscopy (FCPM) has been developed and applied to three-dimensional
observation of local orientation in LC3). In this study, we observed the three-dimensional structure of the
stripe pattern and the square lattice pattern in ChLC by FCPM.
FCPM makes it possible to acquire local orientation of LC in three-dimension under a polarized laser
by adding small amount of fluorescent dye which orients parallel to the LC. The used ChLC in this study
is a mixture of a chiral dopant, an NLC with negative dielectric anisotropy and a surfactant. The pitch
was adjusted by the concentration of the chiral dopant. This sample was sealed in a planar cell and an
AC electric field was applied perpendicular to the cell surfaces.
In the absence of electric field, the structure exhibits a stack of flat layers of ChLC parallel to the cellsurfaces. The one layer corresponds half helical pitch. Above a certain threshold voltage, the layers
begin to undulate in a sinusoidal form. Their magnitude increases and the layers become rectangularform with increase of electric field. Further increase of layer deformation results in the increase of thenumber of layers. Such deformation occurs in one dimension for the stripe pattern and in two
dimensions for the square lattice pattern. In addition, we dispersed micrometer-sized particles in ChLC
and tracked their positions to visualize the convective flow. For example, they rotate around the lattice
points with a constant angular velocity in the square lattice pattern.
This work is supported by JSPS KAKENHI (JP20H02947).
References[1] H. Miike, T. Kohno, K. Koga and Y. Ebina, J. Phys. Soc. Jpn. 43, (1977) 727.
[2] S.V. Belyaev and L.M. Blinov, JETP Lett. 30, (1979) 99.
[3] I. I. Smalyukh, S.V. Shiyanovskii, O. D. Lavrentovich, Chem. Phys. Lett. 336, (2001) 88.

P29

Photoinduced Charge Behaviors in a Liquid Crystal Mixture
on Different Measurement Frequencies
Masaru Inoue1*, Sudarshan Kundu2 and Hiroshi Yokoyama2

1 TOYOTech LLC, USA
2 Advanced Materials and Liquid Crustal Institute, Kent State University, USA* masaru.inoue@toyotechus.com

We proposed a photoinduced charge measurement of Liquid Crystal (LC) mixtures by irradiating alight which is a selected wavelength by monochromator [1]. In this research, we investigated a changeof photoinduced charge in an LC mixture by changing the measurement frequency.
Figure 1 shows the block diagram of the measurement. We irradiated the light from Xe lamp to cells
through the monochromator that can scan the wavelength from 280 nm to 780 nm by 10nm step. We
applied ±10 V triangular waveform voltage to an LC cell by changing the measurement frequency
from 10 Hz to 0.1 Hz and measured the displacement current to obtain the total charge which is
calculated from the entire area of voltage versus current curve in an LC cell on each wavelength. A
photoinduced charge was calculated from the difference of total charge between with and without light
exposure conditions. We prepared MLC2132 (Merck) as an LC mixture which was injected into an
empty cell having the SiN on ITO glass substrates.
Figure 2 shows the wavelength dependency of photoinduced charge of the LC cell by changing themeasurement frequency. We found that the photoinduced charges of each frequency suddenly started
to increase at 360nm, and the photoinduced charge amount increased by decreasing measurement
frequency. We also could see the obvious peak wavelength of 330 nm on 0.1 Hz. The results suggestthat the photoinduced charges are mobile ions which have a mobility in an LC mixture and the light
exposure of 330 nm is a sensitive wavelength for a degradation of the LC mixture.

Fig. 1 Block diagram of photoinduced charge
measurement

Fig. 2 Wavelength dependency of photoinduced
charge on different measurement frequency

Reference[1] M. Inoue, S. Kundu and H. Yokoyama, Proc. IDW’20, LCTp2-3L (2020) 129-130.

P30

Charge Transport Property of Butterfly-like Shape Liquid
Crystals Based Fused-Thiophene as Organic Semiconductors
Hirosato Monobe1*, Tao Ma2, Yu-Jie Zhong2, Hai-Feng Wang2, Ke-Qing
Zhao2, Bi-Qin Wang2, Ping Hu2, and Bertrand Donnio3
1 NMRI, National Institute of Advanced Industrial Science and Technology(AIST), Japan; 2 Col. of Chem. and Mater. Sci., Sichuan Normal University, P.
R. China; 3 IPCMS, CNRS-Université de Strasbourg, France* monobe-hirosato@aist.go.jp

In recent decades, great advances in the chemistry of carbon- and heteroatom-based π-conjugatedsystems have contributed substantially to the emergence of organic electronics and optoelectronics
research domains,[1] as evidenced by the large quantity of synthesized semiconducting molecular andmacromolecular systems for a variety of technological and medical applications. To improve themobility of charges in discotic systems, research attentions have focused on modifying the periphery(nature and type of chains) and/or changing the molecular-core symmetry and size. Beside disc-likemolecules, there have been recently few reports on board-like molecules, pseudo-discs also possessing
large extended π-systems and being able to stack, exhibiting high electronic charge transport mobility
competing with those from conventional DLCs.[2] Structurally related butterfly-like shape molecules
specifically made from fused-thiophene aromatics also stack up into columnar mesophases, and were
found to exhibit outstanding optical properties as well as enhanced electron-conducting properties.[3]In this study, mesomorphous butterfly-like shape molecules based on
cyclopentadithiophen-4-one

andbenzodithiophene-4,8-dione

ROOR

spontaneously self-organize into columnar hexagonal mesophase. The

S

RO

OR
OR
RO

consistent with the high degree of ordering and stability of theOnemesogeninparticularwithbenzodithiophen-4,8-dione core (BDTD) shows outstanding ambipolarcharge carrier transport with both high electron (μe = 6.6×10-3 cm-2 V-1s-1) and hole (μh = 4.5×10-3 cm-2 V-1 s-1) mobility values.[3]

OR
OR

CDTO

photocurrent technique in the mesophases. They display hole-transport

superstructures.

S

RO

charge carrier mobility was measured by time-of-flight transient
performances with positive charge mobility in the 10-3 cm-2 V-1 s-1 range,

OR

O

core

moieties were synthesized. These butterfly-like shape molecules

columnar

RO

OR
O

S

S

O

RO
OR

OR
OR

BDTD

Fig. 1. Board-like and butterfly-shaped
fused-thiophene
columnarliquidcrystalline semiconductors synthesizedby successive Suzuki (bonds in red)and Scholl (bonds in blue) tandem
reactions, BDTD and CDTO, thiswork (R is alkyl chain, CnH2n+1).

References[1] C. Wang, H. Dong, W. Hu, Y. Liu, and D. Zhu, Chem. Rev. 112 (2012) 2208.
[2] Y. Yang, H. Wang, H. F. Wang, C. X. Liu, K. Q. Zhao, B. Q. Wang, P. Hu, H. Monobe, B. Heinrich,and B. Donnio, Cryst. Growth Des. 18 (2018) 4296.
[3] K. C. Zhao, J. Q. Du, H. F. Wang, K. Q. Zhao, P. Hu, B. Q. Wang, H. Monobe, B. Henrich, and B.
Donnio, Chem. Asian J. 14 (2019) 462.
[4] T. Ma, Y. Zhong, H. Wang, K. Zhao, B. Wang, P. Hu, H. Monobe, and B. Donnio, Chem. Asian J.
DOI: 10.1002/asia.202100173.

P31

Viscosity probing function of flapping fluorophores and their
optical properties in a nematic liquid crystal
Ryo Kimura1, Hidetsugu Kitakado1, Hiroyuki Yoshida2, and Shohei
Saito1*
1 Graduate School of Science, Kyoto University, Japan
2 Graduate School of Engineering, Osaka University, Japan* s_saito@kuchem.kyoto-u.ac.jp

Fluorescentmolecular

viscosity

probes are widely used in materials
science and cell biology.[1] We haverecently reported flapping fluorophores,
FLAP, that show viscosity-probing
functions by the analyses of ratiometricfluorescence(FLAP0)[2]and

fluorescence lifetime (FLAP1) (Figure1).[3] These molecules take a V-shaped
conformation as a stable form in the S0
ground state, and they show a V-shapedto-planar conformational change in the S1
excited state. Since the excited-state

Figure 1. (left) Chemical structures of FLAP0 and FLAP1(right) Excited state dynamics of each FLAP.

planarization dynamics is considerably suppressed in highly
viscous media, local viscosity can be estimated by the
analyses of fluorescence properties.
Here we demonstrate that these flapping viscosity probes
are more sensitive than BODIPY-C12[4], a well-studied
molecular rotor working as a fluorescence viscosity probe[3b],particularly in a low viscosity range of 0.3-3 cP. Moreover,
local viscosity of a nematic crystal, 5-CB, has been analyzed
by using these flapping fluorophores, and compared theresults with the reported bulk viscosity of 5-CB (Figure 2). Figure 2. Flapping viscosity probe
dispersed in 5-CB.
Temperature-dependent viscosity change will be also
discussed in relation to the phase transition behavior of 5-CB.
References[1] (a) M. A. Haidekker, E. A. Theodrakis, J. Mater. Chem. C, 2016, 4, 2707. (b) M. K. Kuimova, Phys.
Chem. Chem. Phys., 2012, 14, 12671.
[2] S. Saito et al. (a) J. Am. Chem. Soc. 2013, 135, 8842; (b) J. Mater. Chem. C 2017, 5, 5248.
[3] (a) R. Kimura, H. Kuramochi, P. Liu, T. Yamakado, A. Osuka, T. Tahara, S. Saito, Angew. Chem. Int.
Ed. 2020, 59, 16430. (b) R. Kimura, H. Kitakado, A. Osuka, S. Saito, Bull. Chem. Soc. Jpn. 2020, 93, 1102.
[4] M. K. Kuimova, K. Suhling et al., J. Am. Chem. Soc. 2008, 130, 6672.

P32

Comparison of Characteristics between
Cholesteric Droplets and Cholesteric Cell

Electro-splayed

Ryotaro Ozaki1*, Masashige Manabe1, and Kadowaki Kazunori1

1 Graduate School of Science and Engineering, Ehime University, Japan* ozaki.ryotaro.mx@ehime-u.ac.jp

In recent years, a different approach of utilizing liquid crystal which is in droplet form has received
much attention from researchers in various fields. In this study, we compare the characteristics ofcholesteric liquid crystal (CLC) droplets using electrospray method with CLC in a conventional cell,and investigate the temperature induced phase transition of the droplets. To fabricate the CLC droplets,
we prepared CLC which was a mixture of nematic LC (E44) and 30 wt% of chiral dopant (S-811). We
then set up an electrospray apparatus in which a glass substrate treated with coating agent was placedin between a needle electrode connected to a high voltage source and an earthed plate electrode, as
shown in Fig. 1. About a drop of CLC was applied to the tip of the needle electrode and a negative DC
high voltage of −5kV. The CLC was sprayed to the glass substrate and droplets that were formed werethen observed using a polarized microscope. Figure 2 shows transmittance spectra of CLC in aconventional cell and CLC droplet at 28°C. Although both samples show selective reflection in theirtransmission spectra, the center wavelengths are different. A more detailed approach to the results anddiscussion will be presented at the venue.

Transmittance (%)

100

High voltage

80(a) CLC cell

60
40
20
0
400

50 μm

Transmittance (%)

Glass substrate

100

500

600
700
800
Wavelength (nm)

900

1000

(b) CLC droplet

80

no polarizer

60

right

40

left

20
0
400

Fig. 1 Schematic of fabrication of electro-sprayed
CLC droplets

500

600
700
800
Wavelength (nm)

900

1000

Fig. 2 Transmission spectra of CLC celland CLC droplet.

P33

Phase transition mechanism of liquid crystal revealed
by patterned-illumination time-resolved phase microscope
Nozomi Sato1, and Kenji Katayama1*

1 Department of Applied Chemistry, Chuo University, Tokyo 112-8551, Japan*kkata.@kc.chuo-u.ac.jp

Abstract:

Liquid crystals (LCs) possess long-range molecular interactions, which can be utilized for
macroscopic structural change and motion. Due to this macroscopic change, LCs has been regarded as a good
platform for an active matter in recent years. Although there have been various studies on the structure, thedynamics information on the LC motion is still lacking. We studied how fast and how long this molecularinteraction propagates during a phase transition by observing a change in a refractive index with a high time
resolution. [1] Here, we clarified the initial dynamics of the molecules leading to the phase transition by thepatterned-illumination time-resolved phase microscopy (PI-PM), which could be used for the observation of
the dynamic processes via the images of the refractive index change with a high time resolution.
A sample was N-(4-methoxybenzylidene)-4-butylaniline (MBBA) used as purchased and was put
into an LC cell (E.H.C) with a rubbed polyimide films inside for the planer alignment. By matching apolarization of an illumination light shined onto the sample and the direction of LC orientation, we could
obtain an image of the change in the extraordinary refractive index (∆𝑛e ), and the change in the ordinaryrefractive index (∆𝑛o ) can be imaged by making them vertical.
Figure 1(a) and (b) show the sequences of images for each change in the refractive index. The
white regions in the stripe pattern in Fig. 1(a) corresponds to an increase of the refractive index, while adecrease of the refractive index was observed in the stripe pattern in Fig. 1(b). Fig. 1(c) shows the averagetime responses for each refractive index change obtained by analyzing the images. ∆𝑛e response rose
quickly after the pulse irradiation, on the other hand, ∆𝑛o response started to rise from around 10 ns,
respectively. Both of the signals increased rapidly up to 20 ns followed by an further slow increase up to 2
s. In the previous study, spatially inhomogeneous LC phase transition was reported in photo-induced phasetransition. [2] Based on the above results and reference, we suppose that the 1st rising components until 20 ns
correspond to a local phase transition process caused by a molecular disordering in the direction parallel tothe liquid crystal orientation, and the subsequent 2nd rising components until 2 s correspond to an expansion
process of the phase transition region.

Fig.1

Time sequences of the phase imaging for (a) ∆𝑛e and (b) ∆𝑛o and (c) the corresponding
average time responses.

References:[1] T. Sato and K. Katayama, Sci. Rep. 2017,7, 44801.
[2] A. Shishido, T. Ikeda, et al. JACS. 1997, 119, 7791

P34

Polymerization Induced Fluorescence Enhancement ofAggregation-Induced Emission Dye-Doped Liquid
Crystals
Zijian Fan1*, Hiroyuki Yoshida1, Tsuneaki Sakurai2, and Masanori Ozaki1
1 Graduate School of Engineering, Osaka University, Japan
2 Faculty of Molecular Chemistry and Engineering, Kyoto Institute ofTechnology, Japan* zfan@opal.eei.eng.osaka-u.ac.jp

Introduction: Aggregation-induced emission enhancement (AIEE) is a phenomenon where thefluorescence intensity of a dye increases on becoming a solid [1]. Recently, a class of liquid crystalline
AIEE dyes based on 2-(2-hydroxyphenyl)benzothiazole (HBT) have been synthesized that show highquantum efficiencies with large Stokes shifts due to excited-state intra-proton transfer [1]. Considering
the AIEE nature of the dye, further enhancement of the fluorescence can be expected by polymerizing
the liquid crystal (LC) host. Here, we employed a photo-polymerizable LC as the host material andperformed in-situ measurements of the fluorescence intensity as the host was polymerized.
Fabrication method: The molecular structure of the AIEE dye, HBTC5Ph is shown in Fig 1. A polymerizable LC mixture was prepared bymixing a nematic mixture (LCC, E7), a reactive mesogen (BASF,
LC242), and HBT-C5Ph at a ratio of 69:30:1. A reference materialFig.1 Structure of HBT-C5ph

without the reactive mesogen was also prepared. The LC precursor was
filled in a sandwich cell with uniform homogeneous alignment and acell-gap of 10µm. The fluorescence intensity was measured as a UVLED with peak intensity at 385 nm (Thorlabs, M00268607) was
irradiated on the cell.
Results and discussions: Figure 2 shows the evolution in the
fluorescence spectrum upon irradiation of UV light. The fluorescenceintensity of the polymerizable sample (Fig. 2(a)) shows an increase byapproximately 18 % with a time constant of 4.5 s, which is not observedin the non-polymerizable reference (Fig. 2(b)). The increase is attributed
to the increased viscosity in the polymerized material, which inhibits themolecular motion that causes non-radiative dissipation of energy.
Conclusion: A liquid crystalline AIEE dye was found to increase its
fluorescence intensity when the host LC was polymerized.
Acknowledgment: This work was partly supported by MEXT
KAKENHI (19H02581, 20H00391, 20K21154) and MEXT LEADER
Program.
Reference: [1] W. Zhang et al., Adv. Opt. Mater., 7, 1801349 (2019).

Fig. 2 (a) Fluorescence spectrumof HBT-C5ph doped in thepolymerizable LC and (b) nonpolymerizable.

P35

Title：Detecting Soft Mode in Liquid Crystal Elastomers by
Dynamic Mechanical Tests in Stretched State
Takuho Naraoka 1*, and Kenji Urayama1

1 Department of Material’s Properties Control, Kyoto Institute of Technology,Japan* takuho1998@icloud.com

Introduction
Ideal liquid crystal elastomer (LCE) is theoretically expected to deform at no energy cost when the
director rotates because of the coupling of LC alignment and rubber elasticity, which is called “softelasticity”. Real nematic elastomers(NEs) can be elongated uniaxially at very small constant force whenstretched at large oblique angles relative to the initial director,[1] which has been considered as anindication of soft elasticity. However, the details of the soft elasticity feature in real NEs remain to be
characterized. We investigate the dynamic mechanical properties of the NEs to which a static strain
close to the onset of the plateau regime is applied.
(a)Experiment
The thiol-acrylate main-chain NEs with planarand polydomain alignments (designated as
C6CT-M and C6CT-P, respectively) wereprepared by using the method in Ref [1]. The
rectangular monodomain NEs (C6CT-M- )were cut out from the sample sheet so that thelong axis had an angle () with respect to theinitial director.
The dynamic mechanicalmeasurements were performed in the stretchedstate with various degrees of static elongation
(s).
(b)
Results and discussion
Figure 1(a) shows the quasi-equilibrium stresselongation relationships of C6CT-M-90 and C6CTP. Both specimens indicate quasi-plateau regime
over finite strain range which results from theaccompanying director rotation toward thestretching axis. Figure 1(b) displays the angularfrequency dependence of loss tangent (tan  ) for
each specimen at s = 1.01 and 1.05. In the linear
viscoelasticity regime (s =1.01), tan  for eachspecimen exhibits a definite peak at a characteristicfrequency which reflects the dynamics of director.
Importantly, a small increase in s induces aconsiderable increase in the peak height (tan  max)
for each specimen, and the tan  max values reachFig. 1 (a) Nominal stress-elongation
almost unity. This marked increase in energy dissipation relation (b)  dependence of tan  ofproperty indicates the soft mode feature of NEs becomes C6CT-Poly and C6CT-Mono at various s.
more obvious as the applied stretch approaches the onset The numerals indicate the values of s.
value of the stress-plateau regime.

References[1] Okamoto, S., Sakurai, S., Urayama, K., Soft Matter (2021).

P36

Realization of a Room-Temperature Ferroelectric Columnar
Liquid Crystal by Introducing Branched Alkyl Chains.
Azumi Akiyama1*, Michinari Kohri2, and Keiki Kishikawa2*

1 Graduate School of Science Engineering, Chiba University, Japan
2 Faculty of Engineering, Chiba University, Japan* kishikawa@faculty.chiba-u.jp

Ferroelectrics are materials in which polarization caused by displacement of atoms/molecules oralignment of dipoles is switched by an external electric field and maintained after removal of the field.
Though ferroelectrics are applied to actuators, sensors, non-linear optics, most of them are currently
based on crystalline materials. Some of them contain toxic lead or rare metal elements. On the other
hand, organic ferroelectric columnar liquid crystals (FCLCs) are promising materials that are more
eco-friendly and highly processable, and show lower power consumption compared to crystalline
materials. Achieving FCLCs is still challenging because electrostatic repulsion occurs between
adjacent polar columns in a syn-parallel manner after removal of the field. Further, the temperature
ranges exhibiting FCLCs were
mostly above 100 °C. In ourprevious study, thermodynamicallystable FCLC compound 1 was
generated by introducing chiral alkyl
chains because a tightly woundhelical structure promotes thepolarization maintenance (Fig. 1a).
However, the interactions that were
too strong inhibited its polarization
switching at room temperature [1]. In
thisstudy,
torealizeroom-temperature
FCLCs,
we
focusedonachievingbothpolarization
maintenanceandswitching at room temperature.
Introducing
branched
alkyl
chains is an effective approach for
Fig. 1 (a) Molecular structures of 1–3. (b) Polarization
lowering
liquidcrystalline
maintenance behaviors of compounds 2 and 3.
temperatures and expected tosuppress the molecular thermal motion and prevent the depolarization. The polarization-switchable
temperatures of columnar liquid crystalline compounds 2 (63–143 °C) and 3 (20–165 °C) were lower
compared to that of 1 (105–150 °C). Further, second harmonic generation (SHG) measurements
revealed that induced polarization after removal of a direct current 100 V was partially maintained,
indicating lower-temperature FCLCs (2: 63–103 °C and 3: 20–60 °C) (Fig. 1b). Notably, compound 3
shows an unprecedented room-temperature FCLC and maintains the polarization for at least 18 h.
Dynamics of depolarization in compounds 2 and 3 were further investigated by switching current
measurement, and depolarization activation energies of 2 and 3 were calculated to be 111 and 104 kJ
mol–1, respectively. These energies correspond to that of an FCLC benzene-1,3,5-tricarboxamide (108kJ mol–1) [2]. Thus, we concluded that 2 and 3 generated kinetically stable (slow relaxation) FCLCs.
References[1] A. Akiyama, K. Jido, M. Kohri, T. Taniguchi, and K. Kishikawa, Adv. Electron. Mater. 6 (2020)
2000201.
[2] C. F. C. Fitié, W. S. C. Roelofs, P. C. M. M. Magusin, M. Wübbenhorst, M. Kemerink, and R. P.
Sijbesma, J. Phys. Chem. B 116 (2012) 3928.

P37

Synthesis of nanosheet liquid crystal/elastomer nanocomposite
by using gel template
Akira Shiiyama¹, Toshiki Furukawa¹, Yutaka Ohsedo², Nobuyoshi
Miyamoto¹*
1 Department of Life and Environmental, and applied Chemistry, Graduate
School of engineering, Fukuoka Institute of Technology, Japan
2 Faculty Division of Human Life and Environmental Science, Nara Women’s
University, Japan*miyamoto@fit.ac.jp

Silicone elastomers are important elastomeric materials in rubber industries. Due to its heat resistanceand chemical stability, it is used as a medical device and sealing material. To improve mechanicalproperties and gas barrier properties, compounding inorganic fine particles with silicone elastomers has
been investigated.1-3 Especially, the inorganic nanosheets obtained by exfoliation of a layered material
is attracting attention as anisotropic nanofillers.4-9 However, it is generally difficult to obtain completely
exfoliated nanosheets in a non-aqueous solvent that is required for ideally compounding with silicone
elastomer. Here, we investigated the synthesis of liquid crystalline nanosheet/silicone elastomer
nanocomposite by using the nanosheet liquid crystal composite gel as a template.
An elastomer sample without nanosheets was synthesized by heating the mixture of monomer(diethoxydimethylsilane, tetraethoxysilane) and the catalyst (water, dibutyltin diacetate). As a result, atransparent, strong, and elastic sample was obtained. To synthesize the liquid crystalline
nanosheet/silicone elastomer nanocomposite, a composite gel of nanosheet liquid crystal andpolydiethylacrylamide (pDEAA) was first prepared. The gel was then impregnated with the monomer
solution. The gel remained transparent at this stage, indicating that the introduction of the silicone
monomer into the gel was successful. The polymerization of silicone monomer in this monomerimpregnated gel is now underway and the results will be presented at the poster session. The formationof homogeneous composites is expected after optimization of polymerization conditions.
References[1] Xue, Y.; Li, X.; Wang, H.; Zhao, F.; Zhang, D.; Chen, Y. Mater. Design. 2019, 165, 107580[2] Ismail, N.I.N.; Ansarifar, A.; Song M. Polym. Eng. Sci. 2013, 53, 2603-2614[3] Chen, L.; Chen, G.; and Lu, L. Adv. Funct. Mater. 2007, 17, 898–904[4] Miyamoto, N.; Nakato, T. Adv. Mater. 2002, 18, 1267-1270.
[5] Usuki, A. J. Netw. Polym. Jpn. 2004, 25, 1[6] Inadomi, T.; Ikeda, S.; Okamura, Y.; Kikuchi, H.; Miyamoto, N. Macromol. Rapid Commun. 2014, 35,
1741−1[7] Wong, M.; Ishige, R.; White, L. K.; Li, p.; Kim, D.; Krishnamoorti, R.; Gunther, R.; Higuchi, T.; Jinnai,
H.; Takahara, A.; Nishimura, R.; Sue, H. Nat. Commun. 2014, 5, 3589
[8] Pielichowska, K.; Bieda, J.; Szatkowski, P. Renew. Energ. 2016, 91, 456-465[9] Shahzadi, K.; Mohsin, I.; Wu, L.; Ge, X.; Jiang, Y.; Li, H.; Mu, X. ACS Nano. 2017, 11, 325-334

P38

Self-organization in a nematic phase of Au nanorods modified
with liquid-crystalline organic dendrons
Riko Horiai1, Masaki Matsubara1,2, Takehiro Yachi1, Hideyuki Mitomo3,
Atsushi Muramatsu1, Kiyoshi Kanie1*

1 Institute of Multidisciplinary Research for Advanced Materials, Tohoku
University, Japan
2 National Institute of Technology, Sendai College, Japan
3 Research Institute for Electronic Science, Hokkaido University, Japan* kanie@tohoku.ac.jp
Gold nanorods (AuNRs) show a unique localized surface plasmon resonance (LSPR) depending on
their sizes, aspect ratios, and interparticle interactions. The absorption of AuNRs derived from LSPR
changes when AuNRs are aligned in an ordered structure, which can result in an enhancement of electricfield between AuNRs. On the other hand, liquid-crystalline (LC) organic dendrons are one of therepresentative materials to form self-organized LC structure. Therefore, we focused our attention on thedendron modification of AuNRs to form AuNRs-based thermotropic LC structure,1,2) showing structuredependent dynamic control of their optical properties, by introduction of the self-assembling property
into AuNRs.
Dendron-modified AuNRs were synthesized in a following two-step procedure. Firstly, cethyltrimethyl
ammonium bromide-stabilized AuNRs (CTAB-AuNRs) were prepared. Then, CTABs on the surface of
AuNRs were exchanged by 16-mercaptohexadecanoic acid (MHA) having a COOH-moiety to produce
COOH-modified AuNRs (COOH-AuNRs). Fig. 1 shows a molecular structure of NH2-substituted
dendron used in this study. Secondly, surface modification of the COOH-AuNRs with the dendrons
were performed by forming an amide bond between the COOH-groups on the surface of the AuNRs andNH2-moieties at the terminal of the dendron molecules in the presenceof a condensation agent. The resulting dendron-modified AuNRs(dendron-AuNRs) were characterized by TEM, UV-Vis and SAXS.
Fig. 2 shows TEM images of CTAB-AuNRs and dendron-AuNRs.
The size of AuNRs was 34.6 ± 3.9 nm in the longer axis direction
and 12.9 ± 1.4 nm in the shorter axis direction. Here, the surface-tosurface distance of CTAB-AuNRs was 3.5 nm, while that of dendron- Fig. 1 A molecular structure of
AuNRs expanded to 4.2 nm by dendron-modification. Therefore, the NH2-substituted dendron.
(b)(a)
dendron-modification of AuNRs successfully proceeded, maintaining
the mainlining the rod shape. For the evaluation of thermally orientationof dendron-AuNRs, temperature-dependent SAXS measurements werecarried out. Three broad scattering peaks (d1, d2, and d3) derived fromthe shorter axis of the AuNRs were observed at 30 ℃. As the temperature
Fig. 2 TEM images of (a) CTABrose, they were shifted to the small angle side. Because the reciprocal AuNRs, (b) dendron-AuNRs. The
ratio of d1, d2, and d3 at 150 ℃ is found to calculate as 1: 2: 3, our scale bar in (a) is common to (b).
dendron-AuNRs must form a nematic phase above 150 ℃.
References
1)

K. Kanie, M. Matsubara, X. Zeng, F. Liu, G. Ungar, H. Nakamura, A. Muramatsu, J. Am. Chem. Soc., 134, 808 (2012).

2)

M. Matsubara, W. Stevenson, J. Yabuki, X. Zeng, H. Dong, K. Kojima, S. F. Chichibu, K. Tamada, A. Muramatsu, G. Ungar,
K. Kanie, Chem., 2, 860-876 (2017).

P39

Optical Properties of Cholesteric-Liquid-Crystal Elastomers
with Precisely Controlled Molecular Orientation by
Photopolymerization
Maki Yanagihara1, Kyohei Hisano1, and Osamu Tsutsumi1*

1 Department of Applied Chemistry, Ritsumeikan University, Japan* tsutsumi@sk.ritsumei.ac.jp

Cholesteric liquid crystals (CLC) intrinsically form a helically twisted molecular orientation.
Based on the helical orientation, CLC have a periodic distribution of refractive index; thus, they show
unique optical properties such as reflection and diffraction. So far, we fabricated elastomers with athree-dimensional polymer network using CLC to create strain responsive optical materials, exhibiting
both selective reflection and rubber elasticity. This would have a great potential to be used asmechanosensing materials. For furtherly extending our concept, we have focused on the molecularorientation patterns of cholesteric liquid crystal. In this study, we found that the irradiation of a
spatially patterned light to prepare the CLC elastomer by photopolymerization induced a structurewith a periodic change of in-plane refractive index, and that the obtained CLC elastomer showed
diffraction. Here, we report that the optical and mechanical properties of the CLC elastomer films.
Figure 1 shows the molecular structure of the compound used for fabrication of elastomers.
A mixture of liquid crystal monomer (HAB), chiral monomer (CHA), crosslinking agent (HDDA),
plasticizer (5CB), and initiator (Irgacure 651) was sealed in a glass cell with 6-µm cell gap, and theelastomerwas

preparedbyphotopolymerization. The molecularorientation in the elastomer wasobserved by a polarizing optical
microscopy (POM). In the elastomer
films, we observed a striped periodic
structure (Figure 2a). When tensile
strain was applied to the film, thestructural

periodFigure 1. Molecular structures of materials used in this study.

increased.

Diffracted light measurements of the
CLC

film

revealed

that

the
in

diffraction

angle

decreased

proportiontotensilethestrain(Figure 2b).
Figure 2. (a) POM images of the CLC elastomer underapplied strain. (b) CCD images of the transmitted anddiffracted beams incident on the CLC film.

P40

Cholesteric-Liquid-Crystal Polymer Particles with Controlled
Orientation of Helical Axis and Their Application to
Deformation Analyses
Naoya Fukui, Tomoki Shigeyama, Kyohei Hisano and Osamu Tsutsumi*
Department of Applied Chemistry, Ritsumeikan University, Japan* tsutsumi@sk.ritsumei.ac.jp

Flexible, stretchable soft materials have attracted much attention for realizing soft robots,
wearable electronics, etc. One of the large issue for the development of soft materials is quantitative
analysis of deformation with large strain region. Recently, digital image correlation (DIC) technique iswell-known as a practical method to analyze the deformation behavior. In DIC, a random pattern,called a speckle pattern, is formed by spraying particles on a surface to be analyzed; and then, one canvisualize deformation behavior with high spatiotemporal resolution by monitoring the displacement of
the speckle patterns. Nowadays. two-dimensional analysis by DIC enables to quantitatively investigate
deformation behaviors even with complexed shape changes such as bending and twisting. For further
development, three-dimensional analysis of deformation has been highly desired.
As an origin of speckle patterns, cholesteric liquid crystals (Cho LCs) might be useful. The
Cho LCs form helically twisted molecular alignment, and exhibit selective reflection at a certain
wavelength depending on its helical pitch. Since the helical pitch of Cho LCs can be easily controlled,
Cho LCs have a potential application to multi-colored speckle pattern, allowing us to monitor thethree-dimensional deformation of soft materials by the DIC technique. However, typical Cho LCs
show angular-dependent reflection; thus, the color of speckle patterns depends on viewing angles,
interfering with monitoring the three-dimensional deformation by the multi-color DIC. Recently, we
have succeeded in preparing a monodispersed polymeric Cho-LC particles with radial orientation of
the helical axis. The particle with the radially oriented helix exhibited omni-directional selective
reflection, and the speckle pattern formed by the Cho-LC particles can be visualized without any
angular-dependence. In this study, the Cho-LC polymer particles were dispersed in a film ofpolydimethylsiloxane, and deformation behavior of the film was observed. We demonstrated that the
Cho-LC polymer particles with the radial helical-axis orientation is useful for the multi-color DIC tomonitor the three-dimensional deformation of soft materials.

P41

Liquid crystallinity of silylated niobate nanosheets synthesized
by using a degradable polymer gel
Kazuki Tanaka1, Shinya Anraku1, and Nobuyoshi Miyamoto*1

1 Graduate School of Engineering, Fukuoka Institute of Technology, Japan* miyamoto@fit.ac.jp

Inorganic nanosheets are plate-like particles having a high aspect ratio and a large specific surface area.
They are obtained by exfoliation of an inorganic layered crystal and it is used as a polymer filler, etc.
Silylation of nanosheets is effective to modify the property and functions of nanosheets. However, it isstill challenging to precisely control the modification ratio and to obtain highly exfoliated modified
nanosheets.1 Here, we demonstrate a novel silylation process of nanosheets to overcome these
problems by using a degradable polymer gel.
According to the previous report, 0.5wt% hexaniobate nanosheets/water colloids were synthesized.2
The monomer (acrylic acid; 6.44×10-3 mol), degradable cross-linker (3,9-divinyl-2,4,8,10tetraoxospiro[5.5]undeane; 6.44×10-4 mol) and photopolymerization initiator (2-hydroxy-4’-(2hydroxyethoxy)-2-methylpropiophenone; 5.47×10-4) mol were dissolved in hexaniobate/water colloid,
followed by photopolymerization to immobilize the nanosheets in the polymer hydrogel. The solventof the hydrogel was exchanged with 0.01M HCl to exchanged the original counter cation of thenanosheets

propylammonium

N,N-dimethylformamide

to(DMF).

proton.
Then,

The
the

solvent

DMF

wassolution

then
of

a

exchangedwithsilylating

agent(3-mercaptopropyl(dimethoxy)-methylsilane) was introduced into the gel, and the silylation reaction
was allowed to proceed by heating at 100℃ for 7 days. After the reaction, the gel was sealed in apressure-resistant container with water and heated at 140℃ for 6 h to decompose the gel and recover
the sylilated nanosheets.
In the IR spectrum of the unmodified nanosheet (Fig. 1a), the peaks due to propylammonium (the thecounter cation of the nanosheet) is observed.
After the proton-exchange, silylating reaction anddecomposition/removal of the acrylic acid gel(Fig. 1b), stretching vibrations of Nb-O-Si(●:1016cm-1), Si-O-Si (○:1085 cm-1), Si-CH3(◎:1259 cm-1) and C-O (◉:1463cm-1), while theamide group C=O stretching vibration (1720
cm-1) due to acrylic acid gel disappeared. The
peak of PA+ disappeared due to ion exchange.
Thus, grafting of the silylating agent and gel

Fig.1 IR spectra of (a) original PA+-Nb6O17

degradation were confirmed.

nanosheet (b) H+-Nb6O17 silylated nanosheet

References[1] Nakato,T.; Hashimoto,S. Chem. Lett. 2007,36, 1240-1241[2] Miyamoto, N.; Nakato,T. J.Phys. Chem. B. 2004, 108, 6152-6159

P42

Title ： Novel Liquid Crystal Droplets for the Detection ofBacterial Toxins
Adele. A Parry1*, Daniel. A Paterson1, Peng Bao1, Cliff Jones1, Sally. A
Peyman1, Jonathan Sandoe2, Richard Bushby1, Stephen. D Evans1, andHelen. F Gleeson1.
1 School of Physics and Astronomy, University of Leeds, UK
2 Leeds Institute of Biomedical and Clinical Science, University of Leeds, UK* py14ap@leeds.ac.uk

Typically, liquid crystals (LCs) are most well known for their use in LC displays (LCDs). In recent years
however, LC droplets have received increased exposure as a result of their numerous applications,
including biosensing. Research into LCs as biosensors is driven by several factors, namely the sensitivityof LCs to physical and chemical reactions at the surface and the resultant change in anchoring strength,
leading to changes in the optical properties of the LC¹. Additionally, the birefringent properties of LCs
mean that no labelling of the target biomolecule is required to produce an optical signal. Their potential
for low-cost, sensitive sensors make them extremely interesting to study².
Here we describe a biosensing system incorporating phospholipid-coated nematic LC droplets
immobilised in a 1wt% agarose gel. Monodisperse lipid-coated LC droplets of the order of ~10µm areproduced using microfluidic devices with a flow-focusing configuration. Disruption of the lipid
monolayer produces an alignment switch from homeotropic (radial) to planar (bipolar). Such switchingof the LC alignment produces a measurable optical response when observed using POM as demonstrated
in Fig 1. We describe said switching of LC droplets when suspended in an agarose gel matrix, whichtakes us a step closer to our goal of a dipstick biosensor. Furthermore, we describe the immoblisation ofchiral LC droplets in the same gel matrix, with the view to utilise the selective reflection properties ofchiral LCs to create biosensors capable of producing colour changes visible with the naked eye.

Fig. 1 Switch in alignment of an LC droplet from homeotropic (radial) to planar(bipolar) upon disruption of the lipid monolayer.

References[1] T. Cronin, Handbook of Liquid Crystals, J.W Goodby, P.J Collings, T. Kato, C. Tschierske, H.F Gleeson& P. Raynes. Wiley (2014)[2] P. Bao, D.A. Paterson, P.L Harrisons, K. Miller, S. Peyman, J.C Jones, J. Sandoe, S.D. Evans, R.J. Bushby& H.F. Gleeson, Lab-on-a-Chip, (2019)

P43

Synthesis of Asymmetric Liquid-Crystalline Viologen Salts
Satoshi Arai1, Yusuke Ohgi1, Khoa V. Le2, Takeo Sasaki2, and YumikoNaka2*
1 Graduate School of Science, Tokyo University of Science, Japan
2 Faculty of Science, Tokyo University of Science, Japan* naka@rs.tus.ac.jp

A viologen salts are functional compounds that
responds to various external stimuli such as electric field
and light, and may exhibit liquid-crystalline (LC)properties depending on their molecular design. In

particular, the ionic site in viologen salts have a large
effect on the LC properties since the ionic LCs undergo
phase formation under the influence of both van der
Waals forces and electrostatic interactions [1]. Therefore,
the molecular structure of ionic site must be carefully
designed. Recently, it has been reported that π-extended
viologens exhibit a SmA phase [2], and that a large
difference in the length of the alkyl chains at both ends ofthe mesogens results in a decrease in the LC-isotropic
phase-transition temperature (TLC-Iso.) [3]. We havesynthesized two kind of viologen salts, as shown in Fig. 1

Fig. 1. Structures of viologen
compounds. (a) 12NN12Tf2N, (b)12NPN12Tf2N, and (c) nNNP12Tf2N.

(a) and (b), for application in photoresponsive materials.
12NN12Tf2N and 12NPN12Tf2N which have symmetricmolecular structures, exhibited SmB phase. In this study, we
designed and synthesized asymmetric viologens to obtain
extended viologens with low order in the LC phase.
An asymmetric 12NNP12Tf2N obtained in this study
exhibited SmA and SmC phases. The crystalline-LC
phase-transition temperature (TCryst-LC) of 12NNP12Tf2N was
confirmed to be below room temperature. nNNP12Tf2Ns (nFig. 2. A polarized optical
micrograph of 12NNP12Tf2N films
before and after UV irradiation (60°C, 19 mW/cm2, 180 min).

= 8, 10, 12, 14, 16) varied the length of the alkyl chain attached to the pyridine to increase theasymmetry were synthesized. SmA and SmC phases were observed in the nNNP12Tf2Ns (n = 8, 10,
12, 14, 16). UV light was irradiated on 12NNP12Tf2N sandwiched in a glass cell. When
12NNP12Tf2N was irradiated with UV light above 60°C, which is the temperature of the LC phase, adark field was observed in the polarized optical microscopy.
Acknowledgment This work was supported by JST CREST Grant Number JPMJCR2095, Japan
References [1] Karel Goossens, et. al., Chem. Rev. 116 (2016) 4643. [2] Pradip K. Bhowmik, et. al.,
Molecules 25 (2020) 2435. [3] Valerio Causin, et. al., J. Mater. Chem. 19 (2009) 9153.

P44

Ratiometric fluorescent force probe that works in organogels
Takuya Yamakado1 and Shohei Saito1*

1 Graduate School of Science, Kyoto University, Japan* s_saito@kuchem.kyoto-u.ac.jp

Flapping molecule (FLAP) has a force-probing
function with a reversible fluorescence spectralchange (Figure 1). This function of FLAP isbased on a ground-state conformational change
without covalent bond cleavage, and themechanical response has been studied in
crystalline[1] and polymeric[2] environments.
However, conventional anthracene-based FLAP (FLAP1) cannot probe local force in the presence ofsolvent molecules (namely, in solution or gel) due to spontaneous planarization in the excited state.[3] In
this study, we synthesized a new FLAP force probe bearing two pyrene units (FLAP2) that showed adual fluorescence even in solution, emitted from both the bent and planar forms.
First, FLAP2 was chemically incorporated into main chains of a polyurethane elastomer without
solvents, and the stretch-induced fluorescence response was demonstrated during tensile testing up to
8.7-MPa stress (Figure 2a,b). Next, an organogel were prepared by swelling the polyurethane elastomer
with mesitylene. Although the breaking stress of the organogel was low (0.57 MPa), stretch-induced
fluorescence response of FLAP2 was observed (Figure 2c,d). These findings will offer a new approachto quantification of local stress concentration in soft materials.

References[1] T. Yamakado, K. Otsubo, A. Osuka, S. Saito, J. Am. Chem. Soc. 140 (2018) 6245.
[2] R. Kotani, S. Yokoyama, S. Nobusue, S. Yamaguchi, A. Osuka, H. Yabu, S. Saito, Nature Commun., in revision.
[3] T. Yamakado, S. Takahashi, K. Watanabe, Y. Matsumoto, A. Osuka, S. Saito, Angew. Chem. Int. Ed. 57 (2018) 5438.

P45

Uniformly oriented cast film of hydroxypropyl cellulose liquid
crystalSadahito Uto* and Risa Matsuura

Faculty of Engineering, Osaka Institute of Technology, Japan* sadahito.uto@oit.ac.jp

It is known that HPC aqueous solution has a cholesteric liquid crystal phase in which the light of acertain wavelength can be reflected selectively. The molecules in the cholesteric phase align as a spiralstructure that gives rise to the selective reflection. The dominant wavelength of the reflection
coincides with the pitch of the spiral. And a bright and colored reflection depending on the pitch canbe observed.
One of the main problems is how to make a sample with uniformly well-oriented molecules. So far,samples have been prepared by applying pressure to the liquid crystal, injecting it into a test-cell andaligning it with rubbing stress with surface of the cell. This conventional cell is made of glass. The
reflected light of this cell, however, was not circularly polarized and the orientation of the cell was notvery good.
In this study, liquid crystal cast films with high crystallinity and good alignment was prepared andcompared with the conventional cells. By drawing the liquid crystal on the slide glass slowly using
gravity, a sample with very good orientation was obtained. The reflected light of this cast film iscircularly polarized and shows clear optical activity. Furthermore, as a result of polarization analysis,
uniform and large optical anisotropy was observed throughout the cast film. The observation resultswith a polarizing microscope are shown in Fig.1. The left photos are the result of a sandwich cell andthe right photos are the result of a cast film, respectively.
Clearly uniform anisotropy isobserved in the cast film. From theseresults, it was found that theorientation of the cast film was very
good.
Since cast film is open on one side,
addition and removal of additive ionscan be easily performed, so application
to variable color devices can also be
expected.

Figure 1: Polarized microscope observation of the films.

P46

Improvement of Switching Speed in Liquid Crystal Millimeter
Wave Phase Shifter Under Bias Magnetic Field
Rentaro Yuri1, Ryota Ito1, Michinori Honma1, and Toshiaki Nose1*
1 Akita Prefectural University, Japan* t_nose@akita-pu.ac.jp

Millimeter-Wave (MMW) is expected to be used for next generation high speed wireless communication
standard. Since the MMWs are extremely high frequency region, they have physical characteristic of strong
straightness like a light beam. Then, control devices such as phased array antenna are indispensable for
MMW applications. Phase shifter is the most important element for phased array antenna. Some liquid crystal(LC) MMW phase shifters have been reported, which are expected as low power consumption and low costdevice.[1,2] We have investigated LC MMW phase shifter that has simple structure by replacing a part ofdielectric of microstrip line (MSL) with liquid crystal.[3] However, since this devise has very thick LC layer
with several hundred μm , it has very long recovery time. In this study, we investigated operating
characteristics of the LC MMW phase shifter under bias magnetic field to improve the recovery speed.
Fig.1(a) shows the structure of LC MMW phase shifter. This device consists of MSL substrate anddielectric substrate including electrode. After combine both substrates, LC material is injected into the cavity
fabricated in the MSL substrate. Fig.1(b) shows LC molecular orientation state under bias magnetic field andelectric field, which corresponds to ON or OFF state. ON and OFF states are switched by electric field undera constant and small enough bias magnetic field. Magnetic field is applied parallel to the initial orientation
direction of the liquid crystal molecules, and electric field is applied perpendicular to the magnetic field.
Fig.2 shows the phase change properties of LC phase shifter from ON state (7.9V) to OFF state (0V) undervarious magnetic biases. It is seen that the recovery speed of this devise is improved by increasing appliedmagnetic field. Recovery time of 290 seconds under 0 gauss magnetic field decreases to 26 seconds under1000 gauss magnetic field.
References[1] H. Maune, M. Jost, R. Reese, M. Nickel, E. Polat, R. Jakoby, IDW’18, LCT7-1 (2018). [2]Tien-Lun Ting, Optics EXPRESS, Vol. 27, No.
12, 10 Jun (2019). [3]K.Iiyama et al, The Japan Society of Physics, 17p-P6-31(2018).

P47

Generation of Focused Vortex Beam by Liquid Crystal
Spiral Zone Plate with Homeotropic and PlanerPatterned Alignment Layer
Yuji Tsukamoto1*, Hiroyuki Yoshida1, and Masanori Ozaki1
1 Graduate School of Engineering, Osaka University, Japan* ytsukamoto@opal.eei.eng.osaka-u.ac.jp

Introduction: Liquid-crystal-based diffractive optical elements (LC-based DOE) are attractive as active
and flat optics [1]. LC-based DOEs with patterned alignment such that the azimuthal orientation of the
LC rotates around a specific point on a substrate (i.e., q-plates) can generate optical vortices (OVs) for
circularly polarized light incident on the device. On the other hand, LC-based DOEs with the LC
orientation patterned in the polar angle direction can generate OVs for linearly polarized light. Here, we
demonstrate homeotropic and planar alignment patterning on a substrate by depositing a silane coupling
agent through a photolithographic approach. A LC spiral zone plate (SZP) is fabricated, and the device
is confirmed to show a clear dependence on linear polarization, in contrast to standard q-plates.
Methods: A spiral zone pattern was patterned on a photo-resist film (TOK, OFPR-800 LB) coated onan ITO glass substrate by photolithography. A self-assembled monolayer (SAM) of a silane coupling
agent (TCI, Octadecyltrimethoxysilane) was vapor-deposited on the substrate, after which the photoresist was removed to create regions with and without the SAM. A planer alignment layer (DIC, LIA03) was then coated on the region without the SAM. A counter substrate with the SAM coated on theentire surface was prepared, and sandwiched to a cell-gap of ~9.0 µm. A nematic LC material (LCC,
E7) was injected into the LC cell.
Results: Figure 1 shows a polarization microscope (POM) image of thesample, which clearly shows regions of homeotropic and hybridalignment. A linearly polarized light with a wavelength of 532 nm wasincident on the sample, and the diffraction image at the focus of the SZP
was observed by a CCD camera (Fig. 2). A vortex beam reflecting theFig.1 the POM image of
the LC SZPtopological charge of the SZP was generated when the azimuth directionof incident linearly polarized light was parallel to the long axis of thehybrid-aligned LC. For perpendicular polarization, the diffraction
disappeared, leaving the light unaffected.
Conclusion: A LC SZP with homeotropic and hybrid patternedalignment was fabricated, and used to generate a focusing OV for linearlypolarized light.
Acknowledgment: The authors thank DIC Corporation for providing
materials. This work was partly supported by MEXT KAKENHI(20H00391), and Osaka University Innovation Bridge Grant.
Reference: [1] A. M. Shaltout and et. al, Science, 364, 6441 (2019)

Fig. 2 the diffraction
image from the sample

P48

Reverse mode smart window by UV irradiation through holepatterned photomask
Teruki Ito1, and Rumiko Yamaguchi2*

1 Electrical and Electronic Engineering Course, Akita University, Japan
2 Graduate School of Engineering Science, Cooperative Major in Life Cycle
Design Engineering, Akita University, Japan* yrumiko@gipc.akita-u.ac.jp

A reverse mode LC cell which is clear in a voltage-off state and a light scattering state in a
voltage-on has been proposed. Some mechanisms of the light scattering have been reported, one is bya microlens array system by using hole patterned electrode [1]. Another is a refractive index
mismatching between a polymer matrix and liquid crystal domains. Light scattering properties havebeen also reported by using both light scattering mechanisms [2]. In this study, we have improved areverse mode property by using two-step UV irradiation method [3] with a hole patterned photomask.
An n-type LC (n = 0.237,  = −5.07) of 95wt% and reactive mesogen of 5wt% were mixed
and the mixture was homeotropically aligned in the cell with the thickness of 9 μm. The hole diameterwas 20 μm and the holes occupy 50% of the photo mask area. The first UV irradiation (365 nm, 20
mW/cm2, 2 J) was performed through a hole patterned photomask. Following, the second UV
irradiation (4 J) was uniformly performed without the photomask. A concentration difference of apolymer matrix in the LC cell is caused by two-step UV irradiation, as shown in Fig. 1. The
electro-optical property was measured and compared to that in the cell by conventional one-step UV
irradiation (6 J). Threshold voltage of the LC cell using photomask was lower than that of a LC cellwithout photomask, as shown in Fig. 2. The polymer poor region causes the low threshold voltage.
Moreover, threshold voltage difference between polymer rich and poor regions causes the micro lensarray effect, which might supply the light scattering.
cell thickness : 9 μm

Fig. 1 Schematic of UV irradiation withphotomask

References

Fig. 2 Electrooptical properties of reverse
mode LC cell[1] T. Nose and S. Sato, Liq. Cryst. 5, 5, 1425 (1989).
[2] Y. Rumiko, S. Kousuke and Y. Satoshi, J. Photopolym. Sci. Technol., 33, 4, 369 (2020).
[3] Y. Rumiko and S. Ryousuke, ILCC, P2-C1-30 (2018).

Elastic constant of Hydrogen Bonded Liquid Crystals Fashioned
Between 4-m-Alkyl Cyclohexane Carboxylic Acids and 4-nalkylbenzoic Acids (nBA)

P49

Rumiko Yamaguchi1* and Hikari Kameko2

1 Graduate School of Engineering Science, Cooperative Major in Life Cycle
Design Engineering, Akita University, Japan
2 Electrical and Electronic Engineering Course, Akita University, Japan* yrumiko@gipc.akita-u.ac.jp
Recent years, hydrogen bonded liquid crystals (H-bonded LC) have been applied to millimeterwave and terahertz applications due to a small absorption coefficient or its anisotropy in those regions[1]. The H-bonded LC cell is used by applying AC (∼ kHz) voltage as well as a conventional LC device.
However, there are a very few papers reported physical properties of H-bonded LC which are required
for the electrical driving. In this study, we have investigated physical properties especially bend, twistand splay elastic constants, K11, K22 and K33, of H-bonded LCs from the viewpoint of the device
application.
A series of H-bonded LCs fashioned between 4-m-alkyl cyclohexane carboxylic acids (CCA) and
4-n-alkylbenzoic acids (nBA) are used, as shown in Table 1. The concentration of H-bonded LC
mixtures is controlled to be a nematic phase in room temperature. The LC with n of 3 only showed asmectic phase. Dielectric constant and transmittance were measured in both homogeneous and twistedoriented cell as a function of applied voltage (1 kHz), then the theoretical curve was fitted tomeasurement results to obtained physical properties, for example of n=5 as shown in Fig. 1, in which
fitting parameters of ∆n, ∆ε, K11, K22 and K33 were 0.13, 0.74, 20, 8 and 29, respectively. All ∆ε showed
positive and was lower than 0.8. We obtained K11, K22 and K33 of H-bonded LC mixtures with different
alkyl chain length n, as shown in Fig. 2. K11 and K33 showed odd-even effect of alkyl carbon number.
K33/K11, decreases with n. K22 slightly increases with n and odd-even effect did not clearly show. K22/K11
is about 0.3-0.5, which is small compared to usual LCs of about 0.5-0.7.
Table 1 H-bonded LC mixtures with mCCA and nBA

3CCA
16.6̇

4CCA
16.6̇

5CCA
16.6̇

fitted curve

80

K11, K22, K33 [pN]

Transmittance %100
experimental
data

60
40
20
0

0

5

10

15

20

Voltage (V)Fig. 1 Theoretical VT curve fitted to measurement resultin the TN cell with n of 5.

2BAnBA (n=2, 4-10)

20

30

wt%
Homo cell

30

K33

20

TN cell

K11

10
0

K22

R2

R3

R4

R5

R6 R7

R8

R9

R10

Fig. 2 K11, K22, K33 of H-bonded LC mixture with different
alkyl chain length n.

[1] R. Ito, M. Honma and T. Nose, Appl. Sci. 8, 2487 (2018).
[2] T. Nose, R. Ito and M. Honma, IEEE Mmicrow. Wireless. Compon. Lett, (in press).

P50

Electrically and optically-tuned LC:PDMS photonic devices
Katarzyna A. Rutkowska1*, Piotr Sobotka1, Szymon Baczyński1, Kasper
Marchlewicz2, Artur Dybko2, and Marcin Juchniewicz3
1 Faculty of Physics, Warsaw University of Technology, Poland
2 Faculty of Chemistry, Warsaw University of Technology, Poland
3 Centre for Advanced Materials and Technologies CEZAMAT, Warsaw,
Poland* katarzyna.rutkowska@pw.edu.pl

Polydimethylsiloxane (PDMS), characterized by high optical transparency and low surface energy is
widely recognized as an interesting, high-quality organic material for micro- and opto-fluidic functional
systems. Another advantage of applying PDMS is its cheap and easy processing. PDMS-based photonic
devices are typically fabricated with use of standard soft-photolithography. In this way, complex
microstructures can be successfully manufactured at much lower cost when compared to traditional glassor semiconductor-based components for integrated optical systems. Moreover, air-channels formed in
PDMS can be easily filled with liquid materials, what is a principle of optofluidics. In our work traditional
fluids are replaced with liquid crystals (LCs) and advantage of proposed solution stems from highanisotropy of such materials, whose properties can be easily tuned by external electric field (due to highelectrooptic effect), as well as by high-power optical fields (due to their significant optical nonlinearity). In
this context electrical and optical tuning along with specific polarization properties of LC:PDMS elements
are easy to be demonstrated. In this communication several designs and practical realization of LC:PDMS
tunable devices together with different cheap and efficient methods for mold fabrication are presented. In
addition, possibility of eutectic liquid electrodes application is shown.

References[1] A.R. Hawkins, H. Schmidt, Handbook of Optofluidics, CRC Press (2010).
[2] S. Baczyński, P. Sobotka, K. Marchlewicz, A. Dybko, K. Rutkowska, Phot. Lett. Poland 12(1) (2020)
22.
[3] K.A. Rutkowska, T.R. Woliński, R. Asquini, L. Civita, L. Martini, A. d’Alessandro, Phot. Lett. Poland
9(2) (2017), 48.

P51

Molecular liquid crystal adhesive that melts by light:
Mechanism elucidation of the photomelting function
Tomoaki Konishi1, Yumi Nakaike1, Mitsuo Hara2, Ryuma Sato3, Yuri
Saida4, Wataru Yajima4, Ryo Shikata4, Masaki Hada4, and Shohei Saito1*

1 Graduate School of Science, Kyoto University
2 Graduate School of Engineering, Nagoya University
3 Cellular and Molecular Biotechnology Research Institute, AIST
4 Graduate School of Pure and Applied Science, University of Tsukuba*s_saito@kuchem.kyoto-u.ac.jp
Recently we have demonstrated a new application of photoreactive columnar liquid crystals, that is,
temporary adhesive that melts by light.1 Here, we have developed a new light-melt adhesive composedof a flapping triphenylene (TP-FLAP)-based columnar liquid crystal.2 Unlike the previously reported
light-melt adhesive based on anthracene units,1 the TP-FLAP adhesive does not require any
photoreaction for the photomelting event, but shows excited-state aromaticity. The adhesive strength isrecovered simply by stopping the light irradiation. Here, molecular-level mechanism of the macroscopic
photomelting behavior is discussed based on the method of the ultrafast electron diffraction analysis.3

Fig.1 Light-melting diagram by flattening of TP-FLAP.

Fig. 2 UV-pulse-induced electron diffraction analysis of the TP-FLAP adhesive.

References[1] S. Saito, M. Hara et al. Nat. Commun. 2016, 7, 12094; JP-Patent 6284184 (registered).
[2] S. Saito, Y. Nakaike et al. JP-Patent application 2019-154772.
[3] M. Hada, S. Saito et al. J. Am. Chem. Soc. 2017, 139, 15792.

P52

Calamitic-discotic bimesomorphic azobenzene-triphenylene
liquid crystals : photo-induced phase transitions of the alkyl
homologues
Hikaru Sanada1 Hiroto Nakamura1, Koji Kitagawa1, Daisuke Tanaka1,
Tsuyoshi Kawai2, Kingo Uchida1*, Yo Shimizu2*,
1 Graduate School of Science and Technology, Ryukoku University, Japan
2 Graduate School of Science and Technology, Nara Institute of Science andTechnology (NAIST), Japan* yo-shimizu@ms.naist.jp, uchida@rins.ryukoku.ac.jp

A

triphenylene

derivative

which

has

six

4-

RO

OR

tetradecyloxyazobenzene units connected via propyleneester linkages exhibits both calamitic and discotic LC
ROphases [1, 2]. Furthermore, it is so interesting that thisbimesomorphy of LC phase transitions is realized in aphotonic as well as a thermotropic manner. Therefore, Sm-

O

R=

OR

RO
(CH2)3Col phase transition mechanism is so much important toORNN

O CnH2n+1

1-Cn-3consider its functional properties. Recently, it
was found that by synchrotron radiation XRD
at SPring-8 for the aligned samples, the Sm-toCol phase transition takes place in relation to aface-to-face interaction among triphenylene
rings within a layered structure of Sm phase andthis indicates that it is strongly affected by thelength of alkyl chains as shown in Fig. 1 [3]. In
this communication, phase transition behavior

Fig.1 Indicated Sm-Col phase transition withmolecular con-formation change.

of the alkyl homologues is shown to compare tothat of the thermal phase transitions.
Fig. 2 shows phase diagram of 1-C12-3 and1-C14-3 under the photoirradiation (= 365 nm).
For 1-C12-3 no specific temperature was found
at

which

Col-SmA-Iso

isothermal

phasetransition is controlled by photo-intensity and

Fig.2 hase diagram of (A) 1-C12-3 and (B) 1C14-3 under the photoirradiation (= 365 nm).

only Col-Sm phase transition was observed,
while 1-C14-3 exhibits such an isothermal photo-induced phase transition sequence.
References[1] D. Tanaka, Y. Shimizu, et al., J. Mater. Chem., 22, 25065(2012).
[2] D. Tanaka, K. Uchida, et al., Mol. Cryst. Liq. Cryst., 2014, 594, 105(2014).
[3] Y. Shimizu, H. Sanada, K. Uchida et al., submitted.

P53

Synthesis of Liquid-Crystalline
Photo-Responsive Properties

Viologens

Exhibiting

Yumiko Naka1*, Riki Saito2, Minami Takahashi2, Satoshi Arai2, Khoa V.
Le1, and Takeo Sasaki1
1 Faculty of Science, Tokyo University of Science, Japan
2 Graduate School of Science, Tokyo University of Science, Japan* naka@rs.tus.ac.jp

Viologens exhibits a reversible redox reaction withcolor change when an electric field is applied. The moststable state of a common viologen is a colorless dication,
which can be reduced to a blue-violet radical cation by
one-electron reduction and to an orange quinoid state by
two-electron reduction. The one-electron reduction can also
be induced by UV irradiation. In other words, viologens alsofunction as photo-responsive sites. Moreover, several cases
have been reported in which liquid crystalline (LC) phase
was observed by designing the molecular structure such as
the length of alkyl chains and the counter anions [1]. If
viologens are given LC properties, the change in alignmentof mesogens may be induced due to the changes inintermolecular interactions by photoirradiation. In this study,
we synthesized the LC viologens (nNPNn-X (n: length ofFig. 1 Chemical structures of LC
viologens (a) and viologen-containing
polymers (b) synthesized in thisstudy.

alkyl chain, NPN: rigid moieties in viologen, X: counter anion)) shown in Fig. 1(a), in which anaromatic ring was introduced between two pyridine rings, in order to obtain LC viologens with both
high birefringence and photo-responsive properties.
The obtained nNPNn-Tf2Ns (n = 10, 12, 14, 16, 18, 20) exhibited a SmB phase. 12NPN12-Tf2N
films in a glass cell were observed by a polarized optical microscope (POM) before and after UV
irradiation. Under cross polarized light, no change in texture was observed after UV irradiation atroom temperature in the crystalline state, but UV-light irradiation at 175°C, which is the temperature
range of the LC phase, resulted in a dark-field image. It was found that a decrease in the LC-isotropic
phase-transition temperature was observed by photoirradiation. However, the blue-violet color causedby the formation of radical cations was not observed. Next, we prepared a polymer with the NPN
moieties in the main chain (Fig. 1(b)). NPN-polymer with a large molecular weight was prepared.
NPN-polymer did not show LC phase. The films were changed from colorless to purple whenirradiated with UV light even in air.
Acknowledgment
This work was supported by JST CREST Grant Number JPMJCR2095, Japan
References[1] Y. Haramoto, M. Yin, Y. Matsuzaka, S. Ujiie, and M. Nagasawa, Liq. Cryst. 19 (1995) 319. V. Causin
and G. Saielli, J. Mater. Chem. 19 (2009) 9153.

P54

Ultrafast Time-Resolved Electron Diffraction Capturing Layer
Stacking Dynamics of Graphene Oxide
Yuki Yamamoto1, Satoshi Ohmura2, Yoshiya Kishibe1, Wataru Yajima1,
Ryo Shikata1, Keishi Akada1, Shoji Yoshida1, Jun-ichi Fujita1, Shin-ya
Koshihara3, Yuta Nishina4, Masaki Hada1*

1 Faculty of Pure and Applied Sciences, University of Tsukuba, Japan
2 Faculty of Engineering, Hiroshima Institute of Technology
3 School of Science, Tokyo Institute of Technology
4 Research Core for Interdisciplinary Sciences, Okayama University* hada.masaki.fm@u.tsukuba.ac.jp

We demonstrated ultrafast time-resolved electron diffraction measurements on a nanosheet liquid
crystal, graphene oxide (GO), to understand their layer stacking dynamics.
Layer stacking of two-dimensional nanosheet materials, e.g., graphene andtransition metal

dichalcogenides, is critical in controlling their physical and transport properties. GO also undergoes
layer stacking along with its photo- and thermal-induced reduction process; however, the mechanismand dynamics during the layer stacking have not been clarified yet. In previous study, we have reported
the ultraviolet (UV) photo-induced reduction mechanism (removal of epoxy-group oxygen) of GO using
ultrafast time-resolved electron diffraction measurements [1]. In the present study, we demonstrated
ultrafast time-resolved electron diffraction to monitor the structural dynamics during the layer stackingof GO induced by UV photoexcitation. The experimental results are combined with the density
functional theory calculations, which reveals that AB-stacking of graphitic domains of GO layers
coincides in ~40 ps on photo-induced removal of the epoxy-group oxygen from the basal plane of GO
via overlapping of the π-electronic orbits of GO layers (Fig. 1).
~40ps

UV Photoexcitation

Epoxy removal

Graphene oxideFig. 1 Electron diffraction pattern from GO thin film (left) and the schematic illustration of thephoto-induced layer stacking of GO (right).
References[1] M. Hada, et. al., ACS Nano 13 (2019) 10103–10112.

P55

Scanning wave photopolymerization: effect of molecular
diffusion of liquid-crystalline monomers on polymerization
behavior
Takuto Ishiyama1,2,
Atsushi Shishido1,2*

Yoshiaki

Kobayashi1,2,

Shoichi

Kubo1,2,

1 Laboratory for Chemistry and Life Science, Institute of Innovative Research,
Tokyo Institute of Technology, Japan
2 Department of Chemical Science and Engineering, School of Materials andChemical Technology, Tokyo Institute of Technology, Japan*ashishid@res.titech.ac.jp

Control of molecular alignment in liquid-crystalline (LC) polymer films is key to developing highperformance devices with optical, electronic and mechanical functions. As a molecular alignment
method, application of mechanical stress is the simple and powerful way for fabricating one-dimensionalalignment over large area. On the other hand, a photoalignment method has attracted much attention due
to its clean and non-contact processes. Photoirradiation with linearly polarized light causes a
photochemical reaction of photoresponsive dyes and induce the alignment of the dyes and surrounding
LCs depending on the polarization direction [1]. This advanced technology has already achieved various
applications such as state-of-the-art displays. Recently, we have proposed a novel photoalignment
method based on molecular diffusion caused by the polymer concentration gradient, termed scanningwave photopolymerization [2-4]. In this study, we report a specific polymerization behavior in scanningwave photopolymerization. The effect of molecular diffusion on the photopolymerization behavior wasinvestigated by measuring the molecular weight of the polymers obtained under various
photopolymerization conditions.
We prepared a photopolymerizable sample by mixing aOmethacrylate monomer M6BACP and a photoinitiator

O

O

Polarized optical microscopy and polarized UV-vis absorption

monomer conversion of the resultant polymers were evaluatedOO

made glass cell, and irradiated with a scanned UV slit light.

to the light scanning direction. The molecular weight andCNO

M6BACP

Irgacure 651 (Fig. 1). The sample was injected into a hand-

spectroscopy revealed LC moieties in the films aligned parallelO
O

Irgacure 651
Fig. 1 Chemical structures of thesample used in this study.

by gel permeation chromatography (GPC). The polymer films fabricated by scanning wave
photopolymerization and static photopolymerization showed different conversion and molecular weight
distribution. These results suggest that molecular diffusion caused a specific polymerization behavior.
References[1] T. Seki et al., Polymer 54, (2013) 6053.
[2] K. Hisano, A. Shishido et al., Sci. Adv. 3 (2017) e1701610.
[3] K. Hisano, A. Shishido et al., J. Opt. Soc. Am. B 36 (2019) D112.
[4] M. Aizawa, A. Shishido et al., J. Opt. Soc. Am. B 36 (2019) D47.

P56

Controlled Formation of Topological Defects of Liquid Crystalsin Micro-Chambers
Haruka Sakanoue,1 Tomoki Murakami,2 Hiroaki Suzuki,2, and Kenji
Katayama1*
1 Department of Applied Chemistry, Chuo University, Japan
2 Department of Precision Mechanics, Chuo University, Tokyo 112-8551, Japan* kkata@kc.chuo-u.ac.jp

Topological defects are structural singular points, and they have attracted much attention in the field of
liquid crystal (LC) these days. Although the topological defects themselves occupy a small portion of
an LC in structure, they could control the overall structure, motion, and activity.[1,2] They have beenstudied in terms of the physical properties and extended for practical applications for optics. Since
biological cells form their alignment to make topological defects, the concept was extended forunderstanding the structure and motion of biological phenomena.
We have studied the molecular alignment change of LCs around topological defects from theinterests in the molecular interactions there. For a double emulsion made of an LC as a shell, the photoinduced phase transition was induced from a topological defect center.[1] We have recently developed
a new microscope to study the micro-scale behavior of the molecular orientation changes around
topological defects and found that the molecular orientation angle and ordering occurred step-by-step,
instead of changing them at the same time.[2] For the basic understanding of the topological defects, it
is desired to have an isolated topological defect in a controlled manner. Inspired by the works by Kim
and Serra works,[3,4] there is a possibility that the
topological defects could be stabilized by microstructures, and we have developed a more robust andsimple method to produce isolated topological defects

10 μm

20 μm

20 μm

8 μm

20 μm

20 μm

with high reproducibility by using pre-designed
microfabricatedpolydimethylsiloxane(PDMS)

chambers. The micro-chambers were prepared by
capping a glass substrate on PDMS. The topologicaldefects were stabilized by optimizing the size and theshape and satisfying the boundary conditions insideeach chamber, which was controlled by the air-plasma
treatment on the surfaces. We found the optimal

Figure The demonstration of the isolated
topological defects using micro-chambers. The
number indicated was the diameter of thechamber for each row. The depths weredifferent for each column.

conditions for the reproducible and stable formation of topological defects; a circular shape with its
diameter <10 μm and its depth <15 μm and the glass side was treated by air-plasma, providing a rightbalance of the elastic force to form topological defect at the center. (Figure)
References[1] Y. Dogishi, et al, Entropy 2017, 19, 669. [2] H. Sakanoue, et al, ACS Omega 2019, 4, 13936.
[3] D. S. Kim, et al, Sci. Adv. 2018, 4, eaau8064. [4] F. Serra, et al, Adv. Opt. Mater. 2020, 8, 1900991.

P57

Isotropic-nematic phase transitions in binary mixtures ofbanana-shaped liquid crystalline molecules
Kodai Miyagi and Akihiko Matsuyama

Department of Bioinformatics, Kyushu Institute of Technology Graduate School,
Iizuka, Fukuoka, Japanmiyagi.kodai772@mail.kyutech.jp

Banana-shaped liquid crystalline molecules are attracting attention as molecules with ferroelectricity
and antiferroelectricity. Many theoretical and simulation studies have predicted phase diagrams on thetemperature-bent angle plane [1-3]. However, the phase diagrams of binary mixtures of banana-shaped
liquid crystalline molecules with different bent angles have not been reported yet. In this paper, basedon the previous theory [3] for nematic ordering of a banana-shaped molecule, we construct amean-field theory for the two-component systems of banana-shaped molecules.
We calculate the orientational order parameters of the banana-shaped molecules and study thenematic-isotropic phase transitions, depending on the concentration (volume fraction) and temperature.
We find novel phase diagrams on the temperature (τ) and concentration (𝜙! ) plane. We also discuss
uniaxial and biaxial nematic phases by calculating biaxial order parameters.

Figure1. Phase diagram on thetemperature-concentration plane for thebinary mixture of banana-shaped
molecules with the bent angle θ1 = 90°
and θ2 = 180°. The solid curve show
the first-order isotropic (I)-uniaxial
nematic phase (NUi ,i= a, b, c)transitions [3]. The closed circle shows
the Landau point (LP). Below the LP, thefirst-order phase transition between two
uniaxial nematic phases appears.
Fig.1
References[1] Luckhurst, G. R. Thin solid films, 393, 1 (2001).
[2] To, T. B. T., T. J. Sluckin, and Geoffrey R. Luckhurst. Liq. Cryst., 43, 1448 (2016).
[3] Matsuyama, A., et al. Liq. Cryst., 46, 1672 (2019).

P58

Electroconvection controlled by patterned electrodes
Takumi Fujiwara1,2*, Yutaka Sumino1, Yoshiko Takenaka2

1 Graduate school of Science, Tokyo University of Science, Japan
2 Research Institute for Sustainable Chemistry, National Institute of Advanced
Industrial Science and Technology, Japan* 1520541@ed.tus.ac.jp

Liquid crystal, such as N-(4-Methoxybenzylidene)-4-butylaniline (MBBA), under AC voltage is an
excellent showcase of pattern formation [1]. Close to the bifurcation point, the parallel roll pattern isobserved whose typical length scale is determined by the gap width of a cell, and the pattern with larger
wave number is excited while increasing the applied voltage. However, we found that they can becontrolled by spatial modulation of the electric fields induced by patterned electrodes. Appropriate
spatial modulation of convection will be useful for active smart devices. In this talk, we explore therelationship between the pattern of an electrode and the electroconvection pattern of MBBA.
The pattern of insulated region was given by photoetching of ITO layer, as shown in Fig. 1(a). Here,the diameter of the circles without ITO layer was 50 μm and the lattice constant, the distance between
the centers, was 55 μm. We also prepared the pattern with different lattice constants. We used a cellcomposed of an unetched and a patterned plates, while the gap width was 27 µm. Some regions of thepatterned plate were homogeneously coated with ITO. This region is denoted as H-region and used as areference for the patterned region denoted by P-region. The electrode had uniform planer alignment of
MBBA. MBBA layer was sandwiched in the cell, then, AC voltage (peak-to-peak voltage 𝑉pp ) with
100 Hz was applied. In our condition, a steady parallel roll pattern appeared at 𝑉pp = 19 V at H-region.
When 𝑉pp = 26 V, the roll pattern showed spatial as well as temporal modulation at H-region, i.e., defectturbulence, as shown in Fig. 1(b). On the contrary, the lattice-like convective pattern was formed at Pregion while the temporal modulation was suppressed as shown in Fig. 1(c). This suppression of defectturbulence was effective for the smaller lattice constant of the electrode pattern. In this talk, we willshow the effect of the different patterned electrodes on the electroconvection, and will describe possible
mechanisms and their applications.

Figure1: Electroconvection patterns. (a) Schematic image of the patterned ITO glass slide.
Microscope images of the electroconvection with 𝑉pp = 26V at (b) H-region and (c) P-region.
Reference[1] K. Hirakawa and S. Kai, Mol. Cryst. & Liq. Cryst. 40 (1977) 261.

P59

Nonlinear optical molecular reorientation of oligothiophenedoped fluorinated liquid crystals
Junki Yokota1,2, Kohsuke Matsumoto1,2, Koji Usui1,2, Shoichi Kubo1,2,Atsushi Shishido1,2*

1 Laboratory for Chemistry and Life Science, Institute of Innovative Research,
Tokyo Institute of Technology, Japan
2 Department of Chemical Science and Engineering, School of Materials andChemical Technology, Tokyo Institute of Technology, Japan*ashishid@res.titech.ac.jp

Liquid crystals (LCs) are functional materials that exhibit unique properties such as fluidity andoptical anisotropy [1]. Their optical properties vary by controlling the molecular orientation using
external stimuli such as light and electric fields. In particular, the oligothiophene dye-doped LCs reorient
parallel to the incident polarization direction upon irradiation with a high-intensity laser beam [2-5].
This process, called a photophysical process, occurs only when the LCs are irradiated above a thresholdintensity; thus it has attracted much attention for applications as optical switching and light dimming.
However, the threshold intensity for the molecular reorientation is so high that practical applications are
greatly restricted. In this study, we investigate the effect of host LCs on the nonlinear optical molecularreorientation using fluorinated LCs, which aims to enhance the sensitivity of molecular reorientation.
Host LCs were prepared by adding a fluorinated liquid crystal to 5CB with various ratios. An
oligothiophene dye was doped into the host LCs. The mixtures were injected into glass cells whose
surfaces were treated with a homeotropic alignment layer. Polarized optical microscopy and polarized
ultraviolet-visible absorption spectroscopy confirmed that the LC and dye molecules were
homeotropically aligned. When a laser beam was incident on the cells, diffraction rings appeared on ascreen based on the molecular reorientation. We revealed that adding the fluorinated liquid crystal to
5CB decreased the light intensity at which the first ring appears, indicating that the sensitivity for thephotoinduced molecular reorientation was successfully enhanced.
References[1] T. Kato, et al., Angew. Chem. Int. Ed. 57 (2018) 4355.
[2] H. Zhang, A. Shishido, et al., Adv. Mater. 12 (2000) 1336.
[3] Y. Aihara, A. Shishido, et al., Adv. Opt. Mater. 1 (2013) 787.
[4] J. Wang, A. Shishido, et al., Sci. Rep. 5 (2015) 538.
[5] K. Usui, A. Shishido, et al., ACS Appl. Mater. Interfaces (2021) in press.