UTokyo-IIS Bulletin
Vol.7 February 2021

Institute of Industrial Science,
The University of Tokyo

Ca

Featureaptivated by

W

Professor Kim tackles COVID-19 with innovative
microneedles for testing and delivering vaccines.

ith the COVID-19 pandemic having entered its second year, researchers across the globe are racing to develop technologies
to stop further spread of the potentially deadly virus. Professor Beomjoon Kim of the Institute of Industrial Science, theUniversity of Tokyo (UTokyo-IIS) is no exception: He is applying his research on microneedles to easy-to-use, safe, rapid andcheaper approaches to antigen/antibody testing and vaccine delivery.

Research Associate Jongho Park

Professor Beomjoon Kim

Inspection of active pharmaceutical ingredient molecules inside biodegradable micro needle arrays with ﬂuorescence microscopyProfessor Beomjoon Kim of
UTokyo-IIS’s Center forInterdisciplinary Research on
Micro-Nano Methods became
captivated by the microworld after enrolling at
the institute for a master’s degree upon
graduation from Seoul National University in
1993. “In those days, Japan was amanufacturing superpower and had started tofollow in the footstep of the United States on
research into Micro-Electro-Mechanical
Systems,” Kim said, referring to miniaturized
devices with tiny sensors, actuators andmicroelectronics on silicon wafers. “I initiallyintended to stay at UTokyo-IIS only for mymaster’s degree, but my research was so
exciting that I carried on for a doctorate insteadof going to the United States, which was norm
for South Korean students.”
After researching about tiny sensors at France’s
National Center for Scientific Research (CNRS)
and Twente University in the Netherlands, Kim
returned to UTokyo-IIS in 2000 as an associate
professor. Since then, his dedication to the tiny
world has culminated in the development of
microneedles, including porous microneedles
for diabetes diagnostics that can penetratehuman skin painlessly and extract interstitial
2

UTokyo-IIS Bulletin 2021 February

fluid, a biofluid between blood vessels and cells.
The extraction is done by capillary action, or the
movement of fluid within the spaces of a porous
material due to the forces of adhesion, cohesion
and surface tension. The microneedles arebiodegradable, making them safe to use even if
they break inside the body.

once its development is complete, this will be arevolutionary delivery method because thevaccine does not need to be kept at freezing
temperatures: the vaccine will be freeze-driedfor storage. A person can then simply apply amicroneedle patch to their skin, without the helpof medical professionals.”

As COVID-19 swept the globe during
2020, Kim wondered if his invention
could help the battle against the raging
pandemic. “Luckily for me,
UTokyo-IIS researchers are developing
a diagnostic sensor for COVID-19
antigens/antibodies as well as a
vaccine,” he said, referring to Project
Professors Chieko Kai and Misako
Yoneda. These researchers are
conducting mouse experiments
involving the antigen/antibody testing
kit for COVID-19. The results of theseexperiments are expected to beannounced soon.
“It might take a few years before we
can use microneedles to deliver thevaccine being developed at UTokyo-IIS
because vaccine development requires
testing on humans,” Kim said. “But500 ㎛

Featurea tiny world
How can porous microneedles be useful?

“W

hen a mosquito bites you, it
doesn’t hurt but the area
becomes itchy later,” Kimsaid. “This is because the tipof the mosquito’s sharp, straw-like mouth thatpierces the skin is about 60 micrometers indiameter. Even the tiniest metal injection needle
available for insulin injections is 180
micrometers in diameter, which can be painfulfor patients.”
Kim’s team developed microneedles less than
50 micrometers in diameter at the tip and 0.8
millimeters long, enough to reach the epidermis,
where interstitial fluid can be found. The teamfocused on interstitial fluid as a biomarker
because 95 percent of its constituents are thesame as the blood plasma normally used forsuch a purpose.

addressed microneedle strength and structure
problems. Microneedles for diabetic diagnostics
kits must be strong enough to penetrate into theepidermis, and holes in the needle adjusted
properly to extract the biofluid.
This mechanism can directly be applied to
COVID-19 testing and vaccine delivery. The
sensor under development uses fluorescentmolecules so antigens and antibodies – which aresometimes difficult to detect because of their low
concentration – can be detected about 10 times
more accurately. Antibody tests, unlike PCR
testing, are not suitable for determining if aperson is infected with SARS-CoV-2 (the virus
triggering COVID-19) because people take days
or weeks to develop antibodies. But these tests
could play a key role in determining the overall

prevalence of COVID-19 in general
populations, which is an epidemiologicallysignificant task. After clearing a few technicalhurdles, the tests will likely go on the market.
Using microneedles for vaccinations has muchwider implications. “We can deliver not only
vaccines for COVID-19 but also other vaccines
when our research is successfully completed. It
is painless, easy for lay people to use, and canbe stored without freezing, so they are very
affordable,” Kim said. UTokyo-IIS is currently
conducting joint research with medical
institutions and private firms to put
microneedles to practical use, which is expected
to take a few years. “We will be able to deliver
vaccines to children in Africa very easily, which
would be a huge contribution to society,” Kim said.

Competition to make innovative microneedles
has intensified in recent years, but Kim’s
microneedles still stand out. His diabetic
diagnostics kit was the first to have porous
needles using biodegradable polymers on apaper substrate, by which biofluid in theepidermis is extracted and delivered to thesensor on the paper’s reverse side through a tiny
channel to precisely gauge the glucose level.
The sensor’s color changes depending on the
glucose concentration, and getting a result takes
only a few minutes.
While 90 percent of Kim’s competitors use
metal molds to cure polymers to makemicroneedles, his microneedles can be madewith a 3D printer, allowing the formation of any
shape desired. Intensive research has already

Ultimate goal is to use microneedles for preventive medicineGoing forward, Kim plans tocontinue researching
microneedles for preventive
medicine. “It’s said that one-thirdof the world’s population is prediabetic,” Kimsaid. “Of them, 80 percent are unaware they are
prediabetic. People could use a microneedle
patch at home and at any time so they canregularly monitor their glucose levels.” Kim isconducting research on a microneedle patch
Further information

capable of simultaneously gauging levels ofother heath indicators, such as cholesterol.
“Medical professionals are increasingly
focusing on preventive medicine,” Kim said.
“Microneedles will certainly be crucial for
preventive treatments.”
Away from his research lab, Kim wants tomaster several foreign languages. “When I firstcame here, I could not speak Japanese because

Kim Laboratory
http://www.kimlab.iis.u-tokyo.ac.jp/english/index.html

studying in Japan was not my initial plan. I
learned the language by watching TV,” he said.
“I want to learn Chinese next, and also become
more fluent in Japanese when I retire because
the grammar still sometimes trips me up.
Learning a foreign language is vital as that
opens the door to learning about a country’s
history and culture.”

UTokyo-IIS Bulletin 2021 February

3

Feature

Proj

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ko Yoneda

Project Professor Yoneda takes a step closer to producing a much more
effective COVID-19 vaccine available with a groundbreaking approach.

While conducting experimentsa few years ago, Yoneda
realized how effective a
recombinant measles virus
was in preventing Nipah virus infection, azoonotic illness found mostly in
Bangladesh and India. As the COVID-19
pandemic raged in 2020, Yoneda
decided to apply genetic engineering
technology that uses the measles virus
as a vector to develop a live vaccine
against COVID-19.
In September 2020, Yoneda’ s researchteam started experiments on engineering
a suitable virus for the vaccine at ahigh-level biosafety lab with a grant fromthe Japan Agency for Medical Researchand Development. Within a couple ofmonths, the team succeeded insynthesizing a recombinant measles virus
expressing S protein, a COVID-19 antigen(the pathogen we are trying to vaccine
against). Experiments using hamsters
have proven the recombinant measles
virus’ effectiveness in preventing
COVID-19 infection. Production of an
actual vaccine using the virus isscheduled to begin soon, with the aim ofstarting animal testing in 2021 andPhase-1 clinical trials by early 2022.
“A live vaccine can induce virtually
lifelong immunity against COVID-19,”
Yoneda said. “So, people don’t have toget vaccinated regularly – say once
every six months or every year – asrequired to maintain immunity withinactivated vaccines.”
Live vaccines, which use a version of theliving virus that has been weakened, are
known to induce both antibodies (blood
proteins produced in response to an
antigen) and cell-mediated immunity,
which can provide long-lasting
protection against an antigen.
Cell-mediated immunity is an immune
response in which certain cells aremobilized to destroy antigens in the4

On the other hand, inactivated vaccines
induce only antibodies, resulting in weak
and temporary effects.

Anti-CoV-S antibody titerin vaccinated hamsters
25000
20000

5000
0

2

3

4

5

Days post vaccnine

Induce only antibody

1. Development

Takes time for safety testing

Capable of rapid preparation

2. Effectiveness

Strong immune response
Long-term vaccine efficacy

Weak, transient
Short-term vaccine efficacy
Titer of antibody

Inactivated vaccine

Induce antibody andcellular immune response

1st vac

2nd vac

3rd vacz

Protection level

3. Safety

Potential reversion to virulence

Non-replicating

4. Economical aspect

Lower cost of manufacturing

Need Large number of vaccine

UTokyo-IIS Bulletin 2021 february

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Hamsters were vaccinated twice with measles
vaccine (MV) or Covid19-S expressing measles
vaccine (MV-CoV-S). Anti-S antibodies wereincreased highly in the hamsters vaccinated with
Covid19-S expressing vaccine. The data ofantibody titer was shown as average of 5
hamsters. This result suggested our recombinantvaccine can induce immune response to COVID-19
strongly.

Inactivated form of virus, protein etc.
Non-replicating in the hostProtection level

MV-CoV-S

10000

Attenuated virus
Replicate in the host

1st Vac

MV

15000

Titer of antibody

Live vaccine

infected cells. So far, the only live
COVID-19 vaccine authorized for use isan adenovirus-vectored vaccine, which
Yoneda said is safer, but less effective,
than the vaccine she is developing.

Antibody titerS

ince the global outbreak of
COVID-19 in 2020, hundredsof drug makers have been
racing against time to makesafe, effective vaccines
available to stop the pandemic, which
has claimed over 2 million lives. Whilemost of the vaccines being administeredor tested are inactivated, Project
Professor Misako Yoneda, an appliedveterinary science specialist at
UTokyo-IIS, is taking a unique approach:developing a live, recombinant vaccine
by using the measles virus as a vector.

Titer of antibody is decreased
in a short period.
Seasonal vaccination is
also required.

Feature

Overcoming shortfalls of live vaccinesL

ive vaccines are not without
drawbacks, however. They use
living viruses that canpotentially turn toxic once
they enter the human body. It therefore
takes a longer time to ensure their safety
than inactivated vaccines, whose virus
particles have no disease-producing
capability.
Yoneda’ s research team has alreadyaddressed the safety issue. “The measles
virus has been used for measles
vaccination around the world since the1960s,” she said. “Since its safety has
long been established, there is no
problem in using it as a vector.” A vector

is a means of delivering an antigen that
invades human cells to insert the
antigen’ s code. In fact, the Nipah
vaccine Yoneda was involved indeveloping was confirmed safe, and isscheduled to be put to practical use
shortly in collaboration with the
Coalition of Epidemic Preparedness
Innovations (CEPI), a global partnershipto accelerate the development ofvaccines against emerging infectious
diseases.
Another technical issue is how to insert
the S protein, the main antigen
component in SARS-CoV-2 (the virus
triggering COVID-19), into the vector

through genetic engineering.
Yoneda used the same techniquedeveloped at UTokyo-IIS that was usedin developing the Nipah vaccine. “Until
recently, it was considered difficult tomake genetically engineered viruses
from negative-strand RNA viruses likethe measles virus,” she said. But
UTokyo-IIS succeeded several years ago
in synthesizing a recombinant virus frommeasles virus genes with the help of
so-called supporting plasmids (genetic
structures in a cell that can replicate
independently of chromosomes). That
made genetic engineering much easier.

Trying to clear last hurdleY

oneda said the last hurdle –which could be the biggest
one – for her team’ s
COVID-19 vaccine is to find a
pharmaceutical company that is willingto market the vaccine when all clinical
trials are completed. “It costs much more
to develop live vaccines because wehave to make sure they are safe forpeople,” she said.
Also, the number of vaccine doses
required for the global population ismuch smaller than that for inactivatedvaccines, because live vaccines canprovide lifelong immunity with a few
shots. This sounds like good news, but
for many drug makers it means live
vaccines are not commercially viable.
“We might need a philanthropic
organization like the Bill & Melinda Gates
Foundation to make this vaccine
available to society,” Yoneda said,
adding that several attempts topersuade drug makers to produce andmarket her team’ s COVID-19 vaccine
have failed.
She also hopes the Pharmaceuticals andMedical Devices Agency (PMDA),

Japan’s drug approval authority, willquickly approve her team’ s vaccine,
because the merits of making it widely
available outweigh any attendant risks.
The United States and many othernations have approved COVID-19
vaccines made by drug makers such as
Pfizer/BioNTech and Moderna for
emergency use. “We are conducting
conversations about our vaccine with
PMDA,” Yoneda said, adding that her
team expects to finish Phase 1 of
three-stage clinical testing in a few
months after it starts.

Making contributions to society with her researchYoneda began research on
viruses when she was adoctoral student at UTokyo’ s
Graduate School of
Agricultural and Life Sciences. Her
original interest was not in vaccines, but
in how viruses are host-specific, meaning
how viruses can cause sickness in certain
animals, but not others. She became

deeply involved in developing a vaccine
after studying the Nipah virus. Yoneda
visited an epidemic area in Bangladesh
on a separate project to develop a quick
test kit for the virus. “I was astonished tosee the hygiene and health conditions in
the area,” she said. “I really wanted tohelp them with the vaccine we havedeveloped.”

Yoneda believes she can also make adifference for people in developing
nations with the COVID-19 vaccine she isdeveloping. “It is a huge chance for me
to contribute to society,” she said. “Iwant to build on the technologies andknowledge I have acquired so that I canhelp make the world a better place tolive in.”

UTokyo-IIS Bulletin 2021 february

5

News

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Intern es undercontinusity of, Univer
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Twente:On October 5, 2020,
UTokyo-IIS signed a
Memorandum ofUnderstanding with the
University of Twente’s MESA+
Institute, which is a leading
nanotechnology research institute in
the Netherlands and one of thelargest of its kind in the world.
“This MoU aims at making the tie
between MESA+ and UTokyo-IIS
stronger, particularly in the field ofnanoscience andnanotechnologies,” says Prof.
Kazuhiko Hirakawa, professorof Quantum Semiconductor
Electronics at UTokyo-IIS.

Professor Toshiharu Kishi,
Director General

Netherlands in Japan, in a very
friendly atmosphere. Professor
Albert van den Berg, ScientificDirector of MESA+, andProfessor Kishi signed the MoU
simultaneously and had avirtual handshake while being
physically more than 9,000 kmapart.

According to Prof. Toshiharu
Kishi, Director General of
UTokyo-IIS, “Nanotechnology is
becoming an essential basis formodern electronics, chemistry,
biology, and various other fields.
Indeed, nanotechnology has
become a significant portion of
our research activities at
UTokyo-IIS.”
Prof. Wilfred van der Wiel,
professor of Nano Electronics
and Director of the Center for
Brain-Inspired Nano Systems at
MESA+, used to be a postdoctoral
fellow at UTokyo as well
as Sakigake Fellow(PRESTO Fellow) of theJapan Science andTechnology Agency(JST). His desire tocontinue working withnanotech researchers at
UTokyo has helped to
grow the relationship.

3㎛

As a surprise gift for theoccasion, UTokyo-IIS received
a heap of tulip bulbs from
MESA+. The planting
ceremony was organized on
November 26, 2020 as an
UTokyo-IIS International
Mixer event, where some 40
international andJapanese students,
faculty and staff
gathered on abeautiful sunny day
and worked side byside to plant the tulips
in front of the main
research building of
UTokyo-IIS.

UTokyo-IIS and MESA+“We believe they will be
Topological photonic crystal:
have in common an
blooming beautifully in
A novel way to manipulate photons
interdisciplinary
based on topology
spring as a symbol of ourapproach, which brings
friendship,” says Satoshi
together researchers
Iwamoto, professor ofacross disciplines such as physics,
to further strengthen the
Quantum Nanophotonics at
chemistry, bioscience,collaboration between the two
UTokyo-IIS.
nanoeletronics and nanophotonics.
institutes, by facilitating exchange of
UTokyo-IIS and MESA+ researchers
researchers and students as well as
On March 24 and 25, 2021,
already collaborate in a EU-Japan
sharing of important infrastructures
UTokyo-IIS and MESA+ plan to host
project called EUJO-LIMMS
for nanotechnology research.
an online technical workshop. Even
(Europe-Japan Opening ofthough Tokyo has returned toLaboratory of Integrated Micro
The signing ceremony was conducted emergency mode under COVID-19
Mechatronic Systems), as well as inonline in the presence of His
pandemic in January 2021,
nanophotonics research at a more
Excellency Mr. Peter van der Vliet, the international collaboration will findindividual level. The MoU is expected Ambassador of the Kingdom of the
new ways to go on.
Further information

6

https://www.iis.u-tokyo.ac.jp/en/news/3380/

UTokyo-IIS Bulletin 2021 february

Research Highlights

Associate Professor Oishi
breathes new life into
Tutankhamun artifacts withuse of 3D measurement
and image processing
technologies

Cyber-archaeology, which creates a digital simulation of the past,is revolutionizing how archaeologists preserve and restore
ancient artifacts. Associate Professor Takeshi Oishi of
UTokyo-IIS, an expert in 3D measurement and image
processing, is working closely with the Grand Egyptian Museum
to devise a cutting-edge way to showcase a chariot that might
have carried ancient Egyptian king Tutankhamun.

Ateam led by Associate
Professor Takeshi Oishi of the
Department of Informatics andElectronics has used
cutting-edge technology to substantiatea hypothesis that one of six chariots
excavated from Tutankhamun’s tomb
originally had an overhead canopy. The
discovery makes it the world’s oldest
known chariot – a two-wheeled,horse-drawn vehicle generally used in
racing or warfare – with a canopy.
Oishi’s team digitally reconstructed thechariot with the canopy, which had long
been considered unrelated artifacts andthus displayed separately, for exhibitionat the Grand Egyptian Museum
scheduled to open in Cairo in 2021.

can do is helping make new archaeologicaldiscoveries,” Oishi said.
The museum is considering introducing
augmented reality and virtual reality
technologies that would enable museum
visitors that have smartphones to see how
the chariot might have been used inancient Egypt. The team plans tocooperate with the museum to develop
suitable content for the display.
This project is part of the Grand EgyptianMuseum Joint Conservation Project totransport artifacts stored elsewhere to thenew museum. Under this project,sponsored by the Japan International
Cooperation Agency, the project group,
including archaeologists, trains local staff
tasked with conserving and restoring
artifacts in Egypt. Oishi’s team has also
trained local staff how to conduct 3D
measurements with a structured-lightscanner, which uses projected patterns
and a camera system to measure an
object’s 3D shape. The project’s
achievements were recognized in
November 2020 by the 27th Yomiuri
International Cooperation Awards
sponsored by The Yomiuri Shimbun
newspaper.

“Based on 3D data we gathered from thechariot and the wooden canopy, we tried
to digitally connect both artifacts bystretching the four poles supporting the
canopy. The poles perfectly fit with four
cavities on the chariot,” Oishi said.
Conducting such a project using the realartifacts – which date back to around1330 B.C. – would be extremely difficult
given their fragility, but the team’s 3D
digital reconstruction unlocked amystery that emerged many years after
Oishi has been researching technologies tothe tomb was discovered in 1922. “It isreally satisfying that a technique only we help conserve and restore archaeologicalsites and artifacts since he was a graduate
Further information

Associate Professor
Takeshi Oishi

school student 20 years ago. He has
participated in many archaeologicalprojects including those involving theGreat Buddha statue in Nara, Japan;
Roman temples in Italy; and the Angkor
Thom temple complex in Cambodia.
Oishi’s lack of expertise in archaeology
is actually an advantage of sorts
because he has the freedom to enter
any area of this academic field, be it inEurope, Asia, or the Middle East. “It is
fascinating that computer-assisted
calculations let us see things otherpeople have never seen before,” Oishi
said, adding that the team’s 3D
analytical and image-processing
technology has no parallel in the world.

Nara Great Buddha Mar. 2001

Going forward, Oishi plans to focus ondeveloping automated 3D
measurement technologies with theuse of robotics. “We are measuring thetreasures of humankind,” Oishi said.
“Developing advanced analytic tools
and robots that can measure artifacts
safely and automatically will be
crucial.”

Oishi Laboratory
https://www.cvl.iis.u-tokyo.ac.jp/
UTokyo-IIS Bulletin 2021 february

7Research Highlights

Professor Teruyasu Mizoguchi

Looking Inside the Glass
Scientists at The University of Tokyo study
aluminosilicate glass to determine its complex
local structure with unprecedented detail. This
work may lead to tougher and more inexpensive
glass for touchscreens and solar arrays.

A

team of researchers from
UTokyo-IIS used advanced electron
spectroscopy and computer
simulations to better understand theinternal atomic structure of aluminosilicate glass.
They found complex coordination networks among
aluminum atoms within phase-separated regions.
This work may open the possibility for improved
glasses for smart device touchscreens.

As the demand for smartphones, tablets, and solar
panels increases, so too will the need for morehigh-quality, tough, transparent glass. One of thecandidate materials for these applications is called
aluminosilicate glass, which is made of aluminum,
silicon, and oxygen. As with all amorphous
Reference

8

materials, the glass does not form a simple lattice
but exists more like a disordered “frozen liquid.”
However, intricate structures can still form between
that have not yet been analyzed by scientists.
Now, a team of researchers at UTokyo-IIS haveused electron energy loss fine structure
spectroscopy with a scanning transmission electron
microscope to reveal the local arrangement of atoms
within a glass made of 50% aluminum oxide (Al2O3)
and 50% silicon dioxide (SiO2). “We chose to study
this system because it is known to phase separate
into aluminum-rich and silicon-rich regions” firstauthor Kun-Yen Liao says. When imaging with anelectron microscope, some emitted electrons
undergo inelastic scattering, which causes them tolose some of their original kinetic energy. The
amount of energy dissipated varies based on thelocation and type of atom or cluster of atoms in
the glass sample it hit. Electron loss spectroscopy
is sensitive enough to tell the difference between
aluminum coordinated in tetrahedral as opposed tooctahedral clusters. By fitting the profile of theelectron energy loss fine structure spectra pixel by
pixel, the abundance of the various aluminum
structures was determined with nanometer
precision. The team also used computer
simulations to interpret the data. “Aluminosilicate
glasses can be manufactured to resist hightemperatures and compressive stresses. This
makes them useful for a wide range of industrial
and consumer applications, such as touch displays,
safety glass, and photovoltaics,” senior author
Teruyasu Mizoguchi says. Because
aluminosilicate is also naturally occurring, thistechnique can also be used for geological research.

Atomic structure of glass represented by spheres. Light and deep blue spheres represent aluminum and silicon,
respectively, and red sphere represents oxygen. Sticks in the right ﬁgure represent bonds between a pair of atoms.
Inside the glass, it seems that the atoms are placing randomly as shown in left ﬁgure, but by a careful observation,
it is found that silicon and aluminum are coordinated by a speciﬁc number of oxygens as shown in the right Figure.
The present study revealed a spatial distribution of “number of bonds” for aluminum inside the glass.

Kunyen Liao, Atsunobu Masuno, Ayako Taguchi, Hiroki Moriwake, Hiroyuki Inoue, and Teruyasu Mizoguchi"Revealing Spatial Distribution of Al Coordinated Species in a Phase-separated Aluminosilicate Glass by STEM-EELS”
The Journal of Physical Chemistry Letters (2020), DOI: 10.1021/acs.jpclett.0c02687

UTokyo-IIS Bulletin 2021 February

Research Highlights

Laser-Powered Nanomotors
Chart Their Own Course
Research Associate Yoshito Tanaka

A team of scientists led by the University ofTokyo develop light-driven nanomotorsthat can operate without the need forfocused lasers—work that may allow forincreasingly miniaturized robots andmicrofluidics controlled entirely by light.

Micro-sailboat powered by optical nanomotors is traveling along optical road.

R

esearchers from UTokyo-IIS havedesigned novel linear nanomotorsthat can be moved in controlled
directions using light. This work
opens the way for new microfluidics, including
lab-on-a-chip systems with optically actuatedpumps and valves.
The world of nanoscale machines looks very
different to the one containing the contraptions
to which we have become accustomed. For
example, powering and precisely controlling a
motor smaller than a single bacterium can bemuch more difficult than, say, driving a car.
Now, a team of scientists led by UTokyo-IIS
have introduced a system of linear motors
made from gold nanorods that can move in acontrolled direction when exposed to laser
light. Like a sailboat that can move in any
desired direction by adjusting the rigging,these nanomotors are not constrained to follow
the direction of the light. Rather, they move

Reference

5㎛

based on their orientation even when
exposed to a laser beam traveling fromanother angle.
The motion is powered by the lateral opticalforce created from the sideways scattering oflight from the particles. As a result, the need
to focus or shape the laser beam with lenses,
which was once a difficult task, is eliminated.
In addition, motor sizes are not constrainedby the wavelength of light, unlike withprevious devices.
“Instead of being limited to moving in the
direction of laser light or the field gradient,the direction is determined by the orientationof the nanoparticles themselves,” first author
Yoshito Tanaka says. The key to thistechnology is the localized surface plasmon
resonance—collective oscillations of freeelectrons—within periodic arrays of nanorods.
These can produce scattered light in aparticular direction. “Careful design of theseparation between nanorods leads toconstructive interference in one direction anddestructive interference in the other. This
allows us to produce directional scattering topropel the nanomotor,” senior author
Tsutomu Shimura says.
The researchers envision using thistechnology to create a new platform fornano-sized machinery with moving parts that
followpredetermined
paths while being
nudged along by
unfocused light.
This will greatly
reduce the cost andcomplexity of thesedevices while also
improving precision
Rotation produced by circulararrangement of the nanomotors.
and reliability.

Yoshito Y. Tanaka*, Pablo Albella, Mohsen Rahmani, Vincenzo Giannini, Stefan A. Maier, Tsutomu Shimura"Plasmonic linear nanomotor employing lateral optical forces” "Science Advances(2020), DOI: 10.1126/sciadv.abc3726
UTokyo-IIS Bulletin 2021 February

9Research Highlights

A Shock to the PPE System

Kaori Sugihara has shown that the N95 masks used by health care workers toprevent the spread of COVID-19 can be sterilized and recharged using a van deGraaff generator. This work may lead to a much larger supply of personal protective
equipment for those most likely to be exposed to the virus.

Soft Matter（2020）, DOI: 10.1039/d0sm02004d
Further information

https://www.iis.u-tokyo.ac.jp/en/news/3444/

Ultrasensitive transistor
for herbicide detection in waterA

research team led by Tsuyoshi Minami have fabricated a tiny electronic sensor
that can detect very low levels of a commonly used weed killer in water.
A new polymer-based, solid-state transistor can more sensitively detect a weed killer inwater than existing hydrogel-based fluorescence sensor chips.

Chemistry-A Europian Journal(2020), DOI: 10.1002/chem.202003529
Further information

https://www.iis.u-tokyo.ac.jp/en/news/3427/

Tokyo’s Voluntary Standstill
May Have Stopped COVID-19 in its Tracks

R

esearch shows that Japan’s noncompulsory state of emergency generally
succeeded in reducing human movement. A study from a research team led by
Yoshihide Sekimoto used mobile phone location data for January–April 2020 to recordand plot movement of people in metro Tokyo during the emergence and first wave of
COVID-19. They found a movement reduction of over 50%, which in turn limited social
contact and slowed infection spread.
Scientific Reports(2020), DOI: 10.1038/s41598-020-75033-5
Further information

https://www.iis.u-tokyo.ac.jp/en/news/3393/

0.5°C of additional warming has
a huge effect on global aridityIn a simulation study, a research team led by Hyungjun Kim showed that limiting
global warming to 1.5°C rather than 2°C will be beneficial in mitigating
aridification in many global regions including the Mediterranean, western Europe, andsouthern Africa. However, the changes are not spatially homogeneous, as shown in how
Australia and some parts of Asia are to become wetter rather than drier in the projected
warmer futures. The results imply the importance of regional climate information in theeffort to support policy making decisions on global warming targets.
Environmental Research Letters(2020), DOI: 10.1088/1748-9326/ab9db3
Further information10

https://www.iis.u-tokyo.ac.jp/en/news/3353/

UTokyo-IIS Bulletin 2021 FebruarySince its establishment in 1949, the Institute of Industrial
Science at the University of Tokyo(UTokyo-IIS) is one of thelargest university research institutions in Japan and its history
reaches 70 years.
Our multidisciplinary research covers nearly all fields ofengineering, and our professors, associate professors, andlecturers each lead dedicated laboratories, about 120 in total.
More than 1,000 personnel, comprising approximately 300
faculty members including staffs and 750 graduate students,
participate in educational and research activities that are
responsible for producing excellent research outcomes andfostering outstanding talent. All our laboratories belong to oneof five core research departments and some straddle multiple
departments, providing the warp and weft for nine research
centers, three collaborative research centers, and twointernational collaborative research centers. As well as
promoting original research in each specialist field, we as an
institution encourage cross-disciplinary and international
activities. Last year saw the functions of the Chiba Experiment
Station transferred from its original home in Nishi-Chiba to our
Kashiwa campus, and the launch of the new Design-Led X
Platform.
Since the foundation of the Institute, we have been acutely
aware that the significance of academic research into
engineering lies in its real-world implementation, and together
with the seeding of new academic disciplines throughenhanced specialization and cross-disciplinary collaboration,
we have developed and deployed new technologies that
contribute to solving problems in the real world. We have also
made it our mission to nurture talented people to shoulder the
responsibility of technological development anddissemination, especially in the industrial world. Such aphilosophy and sense of mission has been programmed into
our DNA since the foundation of the Institute, and we havetaken a hands-on approach to address engineering challenges
as a pioneer of advocacy for collaboration between industry

Professor Toshiharu Kishi, Director Generaland academia. We also take pride in the fact that ourachievements and proactive stance are widely recognized
together with the name Seiken.
Society is facing diverse problems today, and expectations are
growing for the role that engineering plays in solving these
problems. At the same time, the challenge for conventional
engineering is that it is unable to make widely-accepted andcompelling products with an approach that focuses only ontechnological development. For such situations that are
difficult to address with engineering alone, we are seeking tobuild a new Seiken style—one that contributes to the creationof compelling value through innovation, founded on the
pursuit of academic truth as a university research institute, andadding a multidisciplinary approach integrating humanities
and sciences that incorporates exit strategies for real-world
implementation, to the style that it is long known for:barrier-free, cross-disciplinary, practical industry–academia
collaboration, and ambitious international collaboration.
Even though it is the largest of its kind in Japan, Seiken isperfectly sized to maintain a strong sense of organizational
unity, and through our agility and collective strength as aworld-class research institute in the field of engineering, wehope to continue helping to make everyone’s dreams come true.

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
Large-Scale Experimentand Advanced-Analysis Platform (LEAP)
5-1-5 Kashiwanoha Kashiwa-shi, CHIBA
277-8574, JAPANE-mail：kashiwa.iis@gs.mail.u-tokyo.ac.jp
Publications
https://issuu.com/utokyo-iis

Five Research Departments and Research Centers

UTokyo-IIS Bulletin 2021 February

11

UTokyo-IIS Bulletin
Institute of Industrial Science,
The University of Tokyo
pro@iis.u-tokyo.ac.jp
https://www.iis.u-tokyo.ac.jp/©2021 Institute of Industrial Science, The University of Tokyo