UTokyo-IIS Bulletin
Vol.11 April 2023

Institute of Industrial Science,
The University of Tokyo

Feature

Developing
A Young Frontrunner Defying

0

ur lives are surrounded by several electronic devices, such as smartphones, PCs, and dazzling
digital billboards. Most people do not question the conventional school of thought that suchdevices are meant to be rigid. However, Associate Professor Naoji Matsuhisa of UTokyo-IIS haschallenged this thought and seeks to develop soft and stretchable electronics.

Associate Professor
Naoji Matsuhisa

A Future Forged by Soft Wearable Devices

Wearable devices have gained a lot of
attention as extended applications offlexible electronics.
Currently, wearable devices such as
smart watches are becoming increasingly popular.
Data that could only be obtained once a week oronce a month previously, can now be obtained 24
hours a day. The obtained data can facilitate thedetection of diseases such as atrial fibrillation and
Alzheimer's disease at early stages with highaccuracy. However, as the benefits of wearable
devices are becoming increasingly apparent, so too
is a major barrier to their adoption, i.e., their"rigidity." There are only a limited number oflocations on the body where rigid devices can beplaced, such as the wrists, fingers, and ears.
Furthermore, many people may feel uncomfortable
wearing such devices.
A soft wearable device that has the samemechanical properties as that of the skin, can stickto the body surface, significantly reducing

discomfort. It is expected that even those who
struggle to understand the implications of wearing
such devices, such as babies and people withdementia, will be able to wear them without
discomfort.
Another key advantage is improved adhesion to theskin, which can dramatically improve the quality ofthe bio-signals that the device acquires. Softelectronic devices can conform to small wrinkles ofthe skin, resulting in a large contacting surface area
between the device and the skin. A larger contact
area results in a stronger adhesive force, which inturn increases the device's ability to track the
movements of the skin surface. This will significantly
reduce the signal noise caused by exercise andother activities.
The COVID-19 pandemic has stressed, yet again,
the importance of at-home medical care. As the
population continues to age, it is expected that the
number of people who will have difficulties visiting
medical institutions will also increase. This will also

increase the number of locations where medicalcare cannot be secured. Hence, soft wearable
devices are expected to become increasingly
important in the future, as the demand forhigh-precision healthcare monitoring and reduced
burden on medical staff increases.

Progressive Utilization in the Field of Robotics

S

tretchable electronics will potentiallyalso play an active role in the field of
robotics.
Soft robots are new types of robots
that are mechanically as soft as humans or animals.
This kind of technology may also play a significant

Reference2role at disaster sites. Unlike factory robots that
handle parts with a fixed shape, robots at disastersites require adaptable responses, such as grabbing
debris and waste, turning valves and levers, or
lifting injured people. Arms made of soft andstretchable materials are able to grab objects

Tokihiko Shimura, Shun Sato, Peter Zalar and Naoji Matsuhisa“Engineering the Comfort-of-Wear for Next Generation Wearables”
Advanced Electronic Materials (2022), DOI: 10.1002/aelm.202200512

UTokyo-IIS Bulletin 2023 April

adaptively and gently. The installation of a soft
sensor on the robotic hand surface will enable therobot to determine the hardness and the textureof the object that needs to be grabbed. This willallow it to gauge important information, such as
the amount of grip strength required.

Further information

Matsuhisa Laboratory
https://www.naojimatsuhisa.com/

Feature

Soft Electronics

Conventional Notions in The Field of Electronics

Revolutionizing How Electronics and Humans ConnectAssociate Professor Matsuhisa is also
exploring novel ways to bring joy topeople using soft electronic devices.
"We are currently developing a displaythat adheres to the skin, which we think can beused for applications such as digital makeup. It will
have the ability to automatically adjust its color
according to the brightness of its surroundings, orcreate facial expressions, such as when one is
nervous. We are unsure if it will be useful, but wehope that people will find it amusing. If we actually
succeed in attaching these devices,high-performance biosensors can be installed
together. Such devices can obtain high-accuracy
biometric information and lead to social impact ona large scale."
Associate Professor Matsuhisa has indicated thatsoft electronics, which defy the conventional ideathat electronics must be hard, have the potential tochange the very way that people view electronics.
"For example, people may feel like hugging stuffedanimals because they are soft, but they may not
feel the same way toward a hard PC. People
perceive rigid devices to be cold and non-living andcannot help but consider them as foreign objects.

However, we believe that when electronic devices
become soft, just like living things, then we willdevelop a sense of familiarity toward them, just like
we do toward stuffed toys. We believe that suchfeelings will change our relationship withcomputers, how we connect with electronics, andhow we think about the data obtained fromelectronics."

ON

OFF

A display that adheres to skin wrinkles (under development). The color becomes darker when the power supply is turned on.

Wide-Ranging Research, from Basic to Applied Research: Forging the Future of Stretchable Electronics

Due to the collaborative research he has
conducted with researchers acrossvarious fields, Associate Professor
Matsuhisa has presented a variety of
results that are not limited to a single field. Whathe prioritizes most in collaborative research is forhis collaborators to feel a mutual bond and senseof connectedness with each other.
"I feel that a strong human bond and the desire to
conduct research specifically with another person
leads to great results. When I was a post-doctoral
researcher at Stanford University, I became goodfriends with a battery researcher at a house party.
The joint research we conducted afterwards led toresearch on stretchable lithium-ion batteries."t
Shor ueg
Dialo

Associate Professor Matsuhisa conducts a varietyof research that ranges from the development ofbasic materials to the construction of devices withfull-scale practical applications. The following areresearch topics that he is currently working on.
"Semiconductors are usually hard silicon materials,
but flexible semiconductors have recently been put
to practical use. Ever since then, we havedeveloped next-generation semiconductors thatare stretchable, and are focusing on thedevelopment of electronic devices that utilize
these semiconductors.
"Another topic is the development of electronic
devices that one would not even perceive uponseeing or touching. We are applying a special
fabrication process that integrates with the skin tocreate a device that feels like it isn't there but isactually there."

Associate Professor Matsuhisa's policy is to use any
material as long as it stretches. He spoke about his
desire to further develop stretchable electronics.
He adds, "For example, inorganic materials arehighly stable, but not soft. Meanwhile, organic
materials have limited stability. Achieving
stretchable electronics requires using the rightmaterials in the right place. Hence, we would beinterested in using a variety of materials."

Associate Professsor
Matsuhisa

Flexible wireless sensor and display system

Professsor Tatsuma
P4-5

I think that a wonderful aspect of this research is that it is not only interesting, but also useful.
In our laboratory, we are conducting research on translucent solar cells,
photodetectors, and quantum dot LED displays.
It would be interesting to add flexibility to such devices in the future too.
That is exactly one of the research themes that we are working on currently.
I believe that there are various methods to achieve this,such as mixing soft organic materials with inorganic quantum dots.
If the variety of materials used increases, so too will the range of their applications.
We are always happy to provide the metal and semiconductor nanoparticles
that we are currently developing, if they will be useful.

UTokyo-IIS Bulletin 2023 April

3

Feature

Mastering Light
Manipulation throughNanomaterials
Advancing Photonic Science and Technology
Through the Discovery of Novel Interactions Between Nanoparticles and LightJ

apan is one of the world leaders inmaterials science—an area of research that
integrates knowledge from various
disciplines, including chemistry andphysics, to design, develop, and evaluate newmaterials that contribute to society. The country has
made invaluable contributions toward
photocatalysts, carbon fibers, carbon nanotubes,
and blue LEDs, all of which are widely usedmaterials in our daily lives. Our institute—
UTokyo-IIS—has also contributed significantly
toward such developments.
One of the core techniques in modern materials
science is the ability to control substances at thenanoscale. At our institute, Professor Tetsu Tatsuma
Plasmonic
is conducting research aimed at developing
Nanomaterials
nanomaterials with unprecedented functions.

Professor
Tetsu Tatsuma

Plasmon-Induced Charge Separation Transfers Electrons
from Nanoparticles to Semiconductors

Prof. Tatsuma focuses on the ability tomanipulate light at will. A variety offunctions can be realized by controllingand utilizing the interaction between
light and nanostructures.
Prof. Tatsuma mainly deals with very small metal
particles, called metal nanoparticles, which areless than 100 nm in size. These metal
nanoparticles are smaller than the wavelength ofvisible light (approximately 380 nm to 750 nm).
Light is a type of electromagnetic wave, and it
propagates through space as a vibration of electricand magnetic fields. When light hits metal, it istypically reflected by the metal's free electrons.
However, metal nanoparticles absorb light owing toa phenomenon called "plasmon resonance,"
whereby the oscillation of the free electrons in themetal nanoparticles resonates with the oscillationof the light's electric field. Depending on the sizeand shape of the nanoparticle, different
wavelengths of light can resonate. This is similar to
how violins produce high-pitched(short-wavelength) sounds, whereas double
basses produce low-pitched (long-wavelength)
sounds. This means that it is possible to create
nanoparticles that resonate with specific colors oflight by controlling their size and shape.
In 2003, Prof. Tatsuma's group discovered a newphenomenon involving plasmon resonance. It was

Reference

Photocatalysts

First plasmonic photocatalyst

UTokyo-IIS Bulletin 2023 April

Tatsuma Group

Chemical Sensing

Direct electrical output
LCP

Rewritable Materials

First multicolor Photochromism

UV

Vis

Photovoltaics

RCP

First PICS cell

UV

100 nmNanophotonic Fabrication

First chiral plasmonic materials
prepared by polarized light

Photomorphing Gels

First photo-swellable / shrinkable gelfound that upon combining metal nanoparticles
with semiconductors, plasmon resonance causes
electron transfer from the nanoparticles to thesemiconductor, resulting in the separation of““PolarizedLight: A Simple Route to Highly Chiral Materials””

Further information

4

Applications of PICS

positive and negative charges. This phenomenon
was named "plasmon-induced charge separation"(PICS) by Prof. Tatsuma, who continues to study themechanism and its potential applications.

https://www.iis.u-tokyo.ac.jp/en/news/2896/

http://www.iis.u-tokyo.ac.jp/~tatsuma/

Feature
Development of Solar Cells and Photocatalysts with Novel Operating Mechanisms

O

dioxide. However, this material can only absorb
ultraviolet light. Metal nanoparticles could allow
the utilization of various other wavelengths of lightfor photocatalysis.
Essentially, PICS uses light energy to separate
positive and negative charges, thereby allowing
the induction of oxidation and reduction reactions,
respectively, using visible light. Additionally, if

ne of the main applications of PICS isphotocatalysis. Photocatalysts arematerials that can trigger chemical
reactions using energy from light. This
concept is based on a phenomenon discovered at
our institute by the distinguished Prof. Akira
Fujishima of the University of Tokyo. Currently,
many practical photocatalysts use titanium

these positive and negative charges are collected
separately, they can be converted into electricity.
Prof. Tatsuma and his team have alreadycombined gold or silver nanoparticles withsemiconductors such as titanium dioxide to
develop "plasmon photocatalysts," solar cells, andphotodetectors, thereby laying the foundation forvarious applications.

Creating Complex Nanomaterials from the Bottom UpP

ICs can further be used to create
intricate nanostructures. In
conventional light-based processing,
there is a limitation called the"diffraction limit," which prevents the
manipulation of features smaller than the
wavelength of light. However, by using plasmon
resonance, light can be confined as "opticalnear-field," around particles smaller than the
wavelength of light. Optical near-field is similar tolight, but it does not propagate and is present
around the surface of an object at a distance ofless than one wavelength of light.
For example, when silver nanocubes are placed ontitanium dioxide and illuminated with light of a
specific wavelength, their position can be selected
such that the optical near-field is confined. When
positive and negative charges are separated at theconfined position, the positive charges can be used
to induce oxidation reactions. In this manner,
metal oxides can be attached to specific positionsby oxidizing metal ions in a solution. By placing
metal oxides that promote chemical reactions at
advantageous positions, we can improve theefficiency and selectivity of plasmon photocatalysts.

The technique of creating nanostructures bystacking atoms or molecules through chemical
synthesis is called the bottom-up method.
Currently, the most widely used nanofabrication
techniques are top-down methods, which involve
processing large materials to create the desired
nanomaterial. However, such methods requirelarge and expensive equipment, resulting insignificant costs, time, and energy consumption.

Discussing the advantages of the bottom-up
method, Prof. Tatsuma says, "Top-down methods
require high cost and energy, and it is difficult toachieve fine and complex three-dimensional
structures beyond the diffraction limit. Using thebottom-up approach, we can achieve low-cost
fabrication of nanoscale three-dimensional
structures, making mass production mucheasier."Yearning to Discover Applications Unique to Each PhenomenonProf. Tatsuma has collaborated with many
universities and companies through joint
research. He believes thatcollaborations are not only a shortcut topractical applications and commercialization but
also an opportunity to understand one's role inresearch and academia.
Tatsuma spoke about his motivation for research,saying, "Rather than taking it upon ourselves to
produce practical applications, I believe that it is
our job to find new phenomena and elucidate themechanisms behind them to pave the way for
applications. I yearn to discover new materials andt
Shor ueg
Dialofind applications unique to these phenomena."
Prof. Tatsuma expects that nanomaterials capableof controlling light will have potential applicationsin the future as metamaterials. Metamaterials arematerials with properties beyond those found innatural materials, such as the ability to control
light freely. They have drawn attention as atechnology that can lead to ultra-high-resolutionlenses, glasses that overlay artificial images on
actual views, and transparent spaceships thatappear in science fiction, among others. Although
the use of metamaterials to control visible light,
which has a relatively short wavelength ascompared to other electromagnetic waves, isdifficult at present, the goal of discovering
potential applications is what drives Prof.
Tatsuma. His efforts aim to create
nanomaterials that interact more strongly withlight by utilizing the interaction between visible
light and metal nanoparticles and connecting
them to metamaterials.
Prof. Tatsuma shares his aspirations for the
future, stating, "It may take time to bringmetamaterials to practical fruition, but I am,
nevertheless, committed to continuing myresearch while I determine the most effective
path forward to ensure that my research willlead to such new technologies."

Professsor Tatsuma

Associate Professsor
P2-3
Matsuhisa

Nowadays, smartphones are equipped with highly advanced cameras.
We could use them to create a practical ultra-high-sensitivity sensor by combining themwith nanomaterials that change color depending on the surroundings.
By the way, I have recently noticed a strong trend toward demanding practical applications of researchin a short amount of time. What are your thoughts on this current situation?
I believe that it is ideal to leave researchers to work diligently on research topics they are genuinely interested inand let potential practical applications arise as a natural consequence.
It is concerning that funding seems to be focused on several research fields with practical applications.
Each researcher's pursuit of their unique interests contributes towards gradual advancement of the research field,
and thereby leads to novel discoveries, one step at a time.
It has been a year since I took up my position at the Institute of Industrial Science,and I feel that the environment here is conducive to conducting in-depth research on topics of interest.
Giving a serious thought to what you just said, Professor Tatsuma,
I intend to thoroughly enjoy the research journey that lies ahead.

UTokyo-IIS Bulletin 2023 April

5

News
Why is the formationof the first hub of One
Health, One worldin Asia significant?
onre changes impact
How does temperatu
h?
ards in Banglades
haz
d
late
t-re
hea
health risk to

The One Health, One World Organization (OHOW) held The 1st International Symposiumon One Health, One World in Pattaya, Thailand from December 8 to 10, 2022.

Professor Kimiro Meguro

Project Professor Chieko Kai

Associate Professor Tsukasa Mizutani

Professor Wataru Takeuchi
Members of OHOW from UTokyo-IIS"O

ne Health, One World," proposed as
the Manhattan Declaration in 2004, isrecognized as a comprehensive
scientific concept that encompasses humanand animal health, the global environment,
urban safety, and urban environmental
management.
This symposium was organized by the
Regional Office for Urban Safety (RNUS),
which was established at the Asian Institute ofTechnology (AIT) in 2002 to improve urban
disaster prevention in the Asian region and tobuild a human network for the purpose, andhas continued for 20 years.
OHOW took over the International Symposium
on New Technologies for Urban Safety of Mega
Cities in Asia (USMCA), which had been heldfor 20 years.

Reference

OHOW: The 1st International Symposium on One Health, One World

Further information

6

The three-day symposium featured six
keynote speeches and 76 researchpresentations on such topics as natural
disasters and infectious diseases,transportation and human mobility, structuraland geotechnical engineering for humansafety, infrastructure health monitoring, publichealth and climate change, and ecosystemmonitoring using remote sensing and GIS.
There were 101 participants from 15
countries including Japan, Thailand, Nepal,
India, Bangladesh, Myanmar, Indonesia,
Cambodia, Philippines, Vietnam, China,
Pakistan, Iran, Sweden, and New Zealand.
Among 44 presentations by young
researchers and students, four were awarded
as the best presenters.

OHOW

UTokyo-IIS Bulletin 2023 April

https://ohow.iis.u-tokyo.ac.jp/

It was the first time in three years since the19th USMCA that the conference was held
face-to-face, providing an opportunity toreunite with old acquaintances and meet
researchers in new fields, while at the sametime providing a meaningful discussion forthe comprehensive and coordinateddevelopment of related academic fields toaddress the various risks facing society fromhuman, animal and global environments that
OHOW targets.
The second meeting is scheduled to be heldin Dhaka, Bangladesh, in December 2023.
ers in Japand from recent disast
How lessons learnermeasures?
nte
cou
er
ast
dis
contribute to future

https://ohow2022.sciforum.net/

News
Project Researcher
Tomomi Sayuda,
UTokyo-IIS

Coral
Rescue Conserve
Together

Research Affiliate
Tai Chong Toh,
National University of Singapore

Research Associate
Sam Shu Qin,
National University of Singapore

Coral Rescue is an experience design project to encourage the general public in coral conservation.
The self-growing coral kit helps to grow corals at home and bring the home-grown corals back to the ocean.
This encourages new interactions with nature to protect marine biodiversity.

On 8 December 2022, DLX Design Lab,
Institute of Industrial Science (IIS),The University of Tokyo (UTokyo) and
The Division of Industrial Design (DID) under
the College of Design and Engineering as wellas the Tropical Marine Science Institute (TMSI)of the National University of Singapore (NUS)
released “Coral Rescue - Conserve Together”.
The project’s aim is to encourage the generalpublic to engage in coral conservation thereby
contributing to maintaining marine biodiversity,
now and in the future.
This will be achieved through a mixture ofdesign artifacts and activities enabling us toreach a wide range of people. We havedesigned a self-growing coral kit (which would
be publicly accessible) that enables anyone tocultivate coral at home. The self-growing coral

Further information

kit is a water tank with a designed rig to help
with coral nurturing. Different coral species
should be used in reef restoration initiatives
to maximize the recovery of marine
biodiversity and ecosystem functioning.
Corals are slow growing. Depending on thecoral’s species, they can take approximately
3 - 6 months to reach a suitable size fortransplantation to the reefs. Once thehome-grown coral reaches an appropriate
size it can be returned to the sea byexperienced divers. We have also developed aworkshop format to educate people about theissues and encourage engagement. For this,we have created support tools such as
displays of local Singapore corals andflashcards related to coral research. In the
future, we would like to build an online
network to enhance activities between
researchers and local volunteers.

Design-Led X Platform https://www.designlab.ac/
Coral Rescue - Conserve Together - / Open Access Coral Conservation

The main challenges faced by researchers incoral conservation include the cost of coral
restoration, climate change impacts and thelack of support from the general public. In
Singapore, the existence of corals is notwidely recognized because of the lack ofseawater transparency. Singaporeans areaccustomed to city life and they are not reallyaware of the existence of coral reefs nearby.
With this Coral Rescue project, we are hoping
to enhance the general public's awarenessand support for the conservation process.
The lead design researcher is Tomomi Sayuda
from the DLX Design Lab at UTokyo-IIS, who
has been kindly hosted at NUS by the DID and
the Keio-NUS CUTE Center. The project has
been informed and inspired by the coralconservation research activities of TMSI at
NUS, in particular those undertaken by
Dr Tai Chong Toh and Sam Shu Qin.

https://youtu.be/HAgyZzuPwyE
UTokyo-IIS Bulletin 2023 April

7

Research Highlights

Radical new treatment systemlights up cancer therapy
Researchers from UTokyo-IIS have developed a streamlined photo-uncaging systemfor photodynamic cancer therapy, using a pulse of light for tumor-specific activation of a cancer-fighting agent.

One approach to treating cancer isphotodynamic therapy using
photo-uncaging systems, in whichlight is used to activate a cancer-fighting agent
in situ at the tumor. However, suitable agents
must be stable under visible light, have ananti-tumor effect in low-oxygen environments,and have the ability to be activated by
low-energy tissue-penetrative red light – a
combination of properties that is difficult toachieve. Now, a team from IIS has developed a
new platform that uses, for the first time,organorhodium(III) phthalocyanine complexes
to achieve this combination of traits.
Conventional photodynamic techniques dependon the formation of reactive oxygen species todestroy tumor cells, but many tumors containenvironments that lack oxygen. Photo-uncaging
systems, where the agent is administered in an
inactive form and then activated, or “uncaged”,
in the location of the tumor, address this issue.
They uncage alkyl radicals, which are known tobe capable of inducing cell death both with andwithout the presence of oxygen. Alkyl radicals
are converted into terminal aldehydes in thepresence of oxygen, and these terminal
aldehydes can also induce cell death. The teamused molecules called “organorhodium(III)phthalocyanine (Pc) complexes” to develop, forthe first time, a novel platform forphoto-uncaging therapy.

They went on to show that the compounds
that were released after the organorhodium(III) phthalocyanine (Pc) complexes wereactivated showed toxicity to HeLa cells, a cellline developed from cancer, indicating thatthese compounds would have the ability tofight cancer if released inside a tumor.

Research Associate
Kei Murata“Our new technology could allow thephotochemical generation of a wide variety ofalkyl radicals and aldehydes, making possible
the site-selective release of various bioactive
molecules,” says senior author Kazuyuki Ishii.
As an improvement on other photo-uncaging
systems, it opens an exciting new avenue forthe treatment of cancer by phototherapy.

“The organorhodium(III) phthalocyanine (Pc)complexes we developed are highly stable
under ambient light during the processes ofsynthesis, purification, and measurement, but
can be activated by a laser that gives out
nanosecond pulses of red light,” explains leadauthor Kei Murata. These nanosecond-pulsing
lasers (pulsing for a billionth of a second) are
relatively easy for medical staff to handle.

Pulsed laser Drug release via bond cleavageof red lightCell
Two-photon
attackabsorption
Alkyl
Alkyl groupradicalO2
Aldehyde

Tumor cells

Organometallic phthalocyanine(Metal center : Rhodium)

Reference

8

Kei Murata*, Yuki Saibe, Mayu Uchida, Mizuki Aono, Ryuji Misawa, Yoshiho Ikeuchi, and Kazuyuki Ishii*“Two-Photon, Red Light Uncaging of Alkyl Radicals from Organorhodium(III) Phthalocyanine Complexes”
Chemical Communications (2022), DOI: 10.1039/d2cc03672j

UTokyo-IIS Bulletin 2023 April

Research Highlights

Professor
Yusuke Kajihara

A Rough Start
Can Lead to a
Researchers at UTokyo-IIS develop a simple but effective method of bonding polymers
with galvanized steel, a material ubiquitous in the automobile industry, to cheaply
and easily create a lightweight and durable product.

T

he manufacturing industry is constantly on
the lookout for more efficientmanufacturing materials, but most new
methods to develop such materials created in
the lab are not suited for industrial-scale use.
Now, investigators from UTokyo-IIS havedeveloped a cheap and simple method ofbonding polymers to galvanized steel—steel witha coating of zinc layered over it—to create alightweight and durable material that canfeasibly be produced on an industrial scale.
As the manufacturing sector becomesincreasingly incentivized to think about theenvironmental impact of their processes, newtechniques are needed to ensure that parts canbe made both sustainably (with a minimum ofharsh chemicals and waste) and with a long
lifetime before needing to be replaced.
Galvanized steel is widely used in the automobile
industry owing to its excellent mechanicalproperties and corrosion resistance. However,
200nm

because of its weight, polymer-metalcomposites are being increasingly applied asalternative lightweight materials with highdurability. Unfortunately, traditional techniques
to bond polymers to galvanized steel are
unsuited for mass production as they often
require harsh chemicals or specialized
equipment.
In a study published recently in the Journal of
Manufacturing Processes, a team ofresearchers at IIS demonstrated a method bywhich a polymer can be bonded to galvanizedsteel simply by pre-treating the steel with anacid wash and dipping it in hot water. The acidwash strips the outer “passive layer” on thezinc coating of the steel which allows the hotwater to form rough nanoscale needle
structures on the true surface. The
researchers discovered that when a polymer
was applied to the treated metal (in a process
called injection-molded direct joining), it filledin the tiny gaps and ridges between and within
the needle structures creating very strong
mechanical linkages. “We found thatimmersion in hot water was a simple andeffective method for producing nanoscale

treated metal surface

polymerstructures on the zinc coating for the polymer
to adhere to, but that prior acid-washing to
remove the passive layer was a necessary stepfor this to occur,” explains lead author Weiyan
Chen.
The group also showed how the tensile-shear
strength, which indicates how much force thepolymer can withstand before being torn off
the metal, increased with the complexity of thenanoscale structures on the galvanized steel
surface. By optimizing the hot watertemperature and treatment time to achieve
peak complexity in the nanoscale structuring,
the team was able to significantly increase thetensile-shear strength compared withuntreated metal. “Our process can be adapted
for a wide range of hybrid joining applications,in which metal and plastic parts need to bepermanently bonded,” says senior author
Yusuke Kajihara. “Furthermore, our method
does not use harsh chemicals or complicatedprocedures and thus is suited to the scale-up
required for industrial application”. This work
could lead to optimization of polymer-metal
joining which would be a significant asset tothe manufacturing industry.

polymer
Metal

Reference

Weiyan Chen*, Fuminobu Kimura, and Yusuke Kajihara“Effect of nanostructured zinc coating on high joining strength of polymer/galvanized high-strength steel composite via injection molding”
Journal of Manufacturing Processes (2023), DOI: 10.1016/j.jmapro.2022.11.044
UTokyo-IIS Bulletin 2023 April

9

Research Highlights

Simulations are Starting to Gel

Feeling Out of Equilibrium in a Dual Geometric World:
A novel theory for nonlinear dissipasive phenomenaA

research team led by Kyohei Takae modified simulations for
aggregation of colloidal particles by including hydrodynamical effectsof the solvent. They revealed that the final structure was different comparedwith older predictions, which may help in designing self-assembling “smart
materials” such as artificial muscles.

Physical Review Letters (2022), DOI: 10.1103/PhysRevLett.129.248001

Further information

https://www.iis.u-tokyo.ac.jp/en/news/4059/

Nerves on the spot: Sensory Neurons
in Human Skin Play Key Role in PigmentationA

research team led by Tetsuya J. Kobayashi extended the utility ofchemical reaction network theory beyond systems in equilibrium using
a mathematical dual geometrical representation. This work may shed light on
the nonequilibrium behavior of reaction networks in chemistry and biology.

Physical Review Research (2022), DOI: 10.1103/PhysRevResearch.4.033208
Physical Review Research (2022), DOI: 10.1103/PhysRevResearch.4.033066

Further information

https://www.iis.u-tokyo.ac.jp/en/news/3976/

Upgrading your Computer to QuantumA

research group led by Yoshiho Ikeuchi has found that sensory neurons
play an important role in human skin pigmentation and physiology.
Specifically, the neurons secrete a protein known as Repulsive Guidance
Molecule B (RGMB), which stimulates melanocytes (the cells in skin that
produce melanin, which is responsible for skin coloration). This study could
lead to the development of new drugs to treat pigmentation disorders.
Cell Reports (2022), DOI: 10.1016/j.celrep.2022.111366

Further information

https://www.iis.u-tokyo.ac.jp/en/news/3977/

A

research team led by Atsushi Kobayashi has demonstrated how ananoscale layer of superconducting niobium nitride (NbNx) can begrown directly onto aluminum nitride (AIN). The arrangement of atoms,
nitrogen content, and electrical conductivity were found to depend on growth
conditions, particularly temperature, and the spacing of atoms in the twomaterials was sufficiently compatible to produce flat layers. The structuralsimilarity between NbNx and AIN will facilitate the integration ofsuperconductors into semiconductor optoelectronic devices.
Advanced Materials Interfaces (2022), DOI: 10.1002/admi.202201244

Further information

10

UTokyo-IIS Bulletin 2023 April

https://www.iis.u-tokyo.ac.jp/en/news/3984/

Professor Toru H. Okabe, Director General

Message from the Director General / Scope

The Covid-19 pandemic has transformed our lives, making us realize
the limits of science and technology against formidable viruses. At thesame time, through remote work and online lectures, we have become
more aware of the importance and the future potential of digitaltransformation (DX). Many issues cannot be solved by technology
alone. However, engineering is expected to play an increasingly
important role in meeting the challenges of modern society, which has
become ever more complicated and diversified.
The Institute of Industrial Science (IIS) at the University of Tokyo is
the largest university-affiliated research institute in Japan. With acommitment to pursuing academic truth, the UTokyo-IIS carries out awide range of educational and research activities, such as
cross-disciplinary research that transcends academic boundaries —which is a traditional feature of the UTokyo-IIS — as well as practicalindustry–academic collaboration, international collaboration, andhands-on research aimed at social implementation.
In 2019, we celebrated our 70th anniversary. During the past 70 years,
there have been significant research accomplishments and we havesucceeded in producing many outstanding members of society.

The UTokyo-IIS is a comprehensive engineering research institute that covers
almost all fields of engineering, consisting of five research divisions. It has
approximately 120 laboratories overseen by professors, associate professors,and lecturers. More than 1,300 personnel, comprising approximately 250
faculty members, 150 support members, and 900 graduate students andpostdocs participate in educational and research activities that are responsible
for producing excellent research outcomes and fostering outstanding talent.
Furthermore, there are 3 affiliated research centers that span multiple research
departments, 7 internal centers, 2 collaborative research centers, and aninternational collaborative research center that pursues international joint
research. In addition to promoting original research in specialized fields, eachlaboratory systematically engages in interdisciplinary or international
activities by using organizations such as the cross-disciplinary research
centers.
In 2017, the Chiba Experiment Station was relocated from its original site in
Nishi-Chiba to the Kashiwa Campus, and since 2020, the facility is operating
as a Large-scale Experiment and Advanced-analysis Platform (LEAP). In
addition, a completely new facility called the “Design-Led X Platform,” thefirst of its kind, has also begun operations in 2017.
Since the foundation of the UTokyo-IIS, we have been acutely aware that thesignificance of academic research in engineering lies in its real-world
implementation. Not only have we created new academic fields throughenhanced specialization and collaboration across disciplines, but we have also
developed and deployed technologies that can contribute to solving problems
in the real world. In addition, we have made it our mission to develop
individuals who will shoulder the responsibility of developing anddisseminating technology in the industrial world.
The spirit and the sense of mission of the UTokyo-IIS since its establishment
still live on, and we tackle various engineering-related issues in a practicalmanner as a pioneering organization advocating industry–academic
collaboration.
Such achievements and such a proactive stance are widely recognized, alongwith the name SEIKEN (short name for IIS in Japanese).
We seek to create a new “SEIKEN style” as we continue to pursue academic
truth as a university research institute, contribute to the creation of new value
through innovation, and aim for a multidisciplinary approach integrating
humanities and sciences for implementation in the real world.
Although the UTokyo-IIS is the largest university research institute in Japan,
it maintains a strong sense of unity as an organization. Using its agility andcomprehensive capabilities, the UTokyo-IIS will continue to fulfill its role as
one of the world’s top research institutes in the field of engineering. We
believe that we will continue to make great contributions to society throughresearch and education.

Five Research Departments and Research Centers

Institute of Industrial Science, The University of Tokyo (UTokyo-IIS)
https://www.iis.u-tokyo.ac.jp/
Komaba Research Campus（Komaba Ⅱ Campus）
4-6-1 Komaba Meguro-ku, TOKYO 153-8505, JAPANE-mail：koho.iis@gs.mail.u-tokyo.ac.jp

Kashiwa Campus
5-1-5 KASHIWANOHA KASHIWA-SHI, CHIBA 277-8574, JAPAN (Kashiwa Campus)
6-2-3 KASHIWANOHA KASHIWA-SHI, CHIBA 277-0882, JAPAN (Kashiwa Ⅱ Campus)
E-mail : kashiwa.iis@gs.mail.u-tokyo.ac.jp

Publications
https://issuu.com/utokyo-iis

UTokyo-IIS Bulletin 2023 April

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UTokyo-IIS Bulletin
Institute of Industrial Science,
The University of Tokyo
pro@iis.u-tokyo.ac.jp
https://www.iis.u-tokyo.ac.jp/©2023 Institute of Industrial Science, The University of Tokyo