ION
-
Expanding the Genetic Code of Mus Musculus
Professor Hee-Sung Park of the Department of Chemistry, who garnered attention for his novel strategy of installing authentic post-translational modifications into recombinant proteins, expanded his research portfolio to another level. Professor Park’s team was the first to report the generation of a mouse strain with an expanded genetic code, allowing site-specific incorporation of unnatural amino acids.
Professor Park published the research on the new chemical biology method for achieving selective chemical modifications in proteins in Science last September. The research team, this time in collaboration with Professor Chan Bae Park of the Department of Physiology at the Ajou University School of Medicine, demonstrated temporal and spatial control of protein acetylation in various organs of the transgenic mouse using a recombinant green fluorescent protein as a model protein. This research was published in the online edition of Nature Communications on February 21.
This approach enables the rapid onset of position-specific acetylation of a target protein at any developmental stage, facilitating temporal and spatial control of protein acetylation in various organs of the transgenic mouse. Such temporal and spatial control of protein acetylation will be of prime importance for investigating many essential biological processes and human diseases at the tissue and organism level.
Almost all human proteins, the products of about 25,000 genes, are known to undergo various post-translational modifications during and after synthesis. Post-translation modifications regulate the function of cellular proteins, playing a key role in many essential processes such as delivering signals and body growth. However, the unusual protein modifications, aroused from genetic and/or environmental factors, trigger severe diseases including cancer, dementia, and diabetes.
The team inserted transgenes into the mouse genome to allocate the site-specific addition of unnatural amino acids. The researchers inserted a modified version of lysine into the house mice, which allowed for the control of the acetylation. They used recombinant green fluorescent proteins from transgenic house mice as models for control of the acetylation.
The team was also able to regulate the acetylation of specific temporal and spatial frames in the mice, restraining the abnormality in proteins to certain organs such as the liver and kidneys. The research team said the strategy will provide a powerful tool for systematic in vivo study of cellular proteins in the most commonly used mammalian model organisms for human physiology and disease. Professor Park said, “This method can be easily extended to generate a wide range of custom-made transgenic mouse strains for further investigating diverse proteins of interest.” He added, “This method can be further extended to generate a wide range of custom-made transgenic mouse strains, opening a new paradigm for investigating anti-cancer and cerebral disease treatments.
This work was supported by grants from KAIST Systems Healthcare and the Medicinal Bioconvergence Research Center and the Intelligent Synthetic Biology Center of the Global Frontier Project funded by the Ministry of Science, ICT & Future Planning and the Ministry of Food and Drug Safety.
(Figure:Temporal and spatial control of in vivo protein acetylation)
(a) Temporal expression of acetylated GFPuv in the AcK-GFPamber mouse. The expression of GFPuv in skeletal muscle, liver, and lung tissues was detected only in the AcK-injected mouse. Scale bar, 200 µm. (b) Western blotting of anti-FLAG-immunoprecipitated proteins from tissues of the AcK-GFPamber mouse. Acetylated GFPuv was produced after AcK injection. (c) Spatial expression of acetylated GFPuv in the AcK-GFPamber mouse. Acetylated GFPuv was observed only in skeletal muscle when AcK was directly delivered to the tissues. Sacle bar, 200 µm.
2017.03.27 View 8469 -
First Mutations in Human Life Discovered
The earliest mutations of human life have been observed by research team led by the Wellcome Trust Sanger Institute and their collaborators. Analyzing genomes from adult cells, the scientists could look back in time to reveal how each embryo developed.
Research team of the Sanger Institute including Professor Young Seok Ju of the Graduate School of Medical Science and Engineering at KAIST published an article of “Somatic Mutations Reveal Asymmetric Cellular Dynamics in the Early Human Embryo” in Nature on March 22.
The study shows that from the two-cell stage of the human embryo, one of these cells becomes more dominant than the other and leads to a higher proportion of the adult body.
A longstanding question for researchers has been what happens in the very early human development as this has proved impossible to study directly. Now, researchers have analyzed the whole genome sequences of blood samples (collected from 279 individuals with breast cancer) and discovered 163 mutations that occurred very early in the embryonic development of those people.
Once identified, the researchers used mutations from the first, second and third divisions of the fertilized egg to calculate which proportion of adult cells resulted from each of the first two cells in the embryo. They found that these first two cells contribute differently to the whole body. One cell gives rise to about 70 percent of the adult body tissues, whereas the other cell has a more minor contribution, leading to about 30percent of the tissues. This skewed contribution continues for some cells in the second and third generation too.
Originally pinpointed in normal blood cells from cancer patients, the researchers then looked for these mutations in cancer samples that had been surgically removed from the patients during treatment. Unlike normal tissues composed of multiple somatic cell clones, a cancer develops from one mutant cell. Therefore, each proposed embryonic mutation should either be present in all of the cancer cells in a tumor, or none of them. This proved to be the case, and by using these cancer samples, the researchers were able to validate that the mutations had originated during early development.
Dr. Young Seok Ju, first author from the Wellcome Trust Sanger Institute and KAIST, said: "This is the first time that anyone has seen where mutations arise in the very early human development. It is like finding a needle in a haystack. There are just a handful of these mutations, compared with millions of inherited genetic variations, and finding them allowed us to track what happened during embryogenesis."
Dr. Inigo Martincorena, from the Sanger Institute, said: "Having identified the mutations, we were able to use statistical analysis to better understand cell dynamics during embryo development. We determined the relative contribution of the first embryonic cells to the adult blood cell pool and found one dominant cell - that led to 70 percent of the blood cells - and one minor cell. We also sequenced normal lymph and breast cells, and the results suggested that the dominant cell also contributes to these other tissues at a similar level. This opens an unprecedented window into the earliest stages of human development."
During this study, the researchers were also able to measure the rate of mutation in early human development for the first time, up to three generations of cell division. Previous researchers had estimated one mutation per cell division, but this study measured three mutations for each cell doubling, in every daughter cell.
Mutations during the development of the embryo occur by two processes - known as mutational signatures 1 and 5. These mutations are fairly randomly distributed through the genome, and the vast majority of them will not affect the developing embryo. However, a mutation that occurs in an important gene can lead to disease such as developmental disorders.
Professor Sir Mike Stratton, lead author on the paper and Director of the Sanger Institute, said: "This is a significant step forward in widening the range of biological insights that can be extracted using genome sequences and mutations. Essentially, the mutations are archaeological traces of embryonic development left in our adult tissues, so if we can find and interpret them, we can understand human embryology better. This is just one early insight into human development, with hopefully many more to come in the future."
(Figure 1. Detection of somatic mutations acquired in early human embryogenesis )
(Figure 2. Unequal contributions of early embryonic cells to adult somatic tissues )
2017.03.23 View 7213 -
Furniture That Learns to Move by Itself
A novel strategy for displacing large objects by attaching relatively small vibration sources. After learning how several random bursts of vibration affect an object's pose, an optimization algorithm discovers the optimal sequence of vibration patterns required to (slowly but surely) move the object to a specified position. Displacements of large objects induced by vibration are a common occurrence, but generally result in unpredictable motion. Think, for instance, of an unbalanced front-loading washing machine. For controlled movement, wheels or legs are usually preferred.
Professor Daniel Saakes of the Department of Industrial Design and his team explored a strategy for moving everyday objects by harvesting external vibration rather than using a mechanical system with wheels. This principle may be useful for displacing large objects in situations where attaching wheels or complete lifting is impossible – assuming the speed of the process is not a concern.
His team designed vibration modules that can be easily attached to furniture and objects, and this could be a welcomed creation for people with limited mobility, including the elderly. Embedding these vibration modules as part of mass-produced objects may provide a low-cost way to make almost any object mobile.
Vibration as a principle for directed locomotion has been previously applied in micro-robots. For instance, the three-legged Kilobots move thanks to centrifugal forces alternatively generated by a pair of vibrations on two of its legs. The unbalanced weight transforms the robot into a ratchet and the resulting motion is deterministic with respect to the input vibration. To the best of our knowledge, we are the first to add vibratory actuators to deterministically steer large objects regardless of their structural properties.
The perturbation resulting from a particular pattern of vibration depends on a myriad of parameters, including but not limited to the microscopic properties of the contact surfaces. The key challenge is to empirically discover and select the sequence of vibration patterns to bring the object to the target pose.
Their approach is as follows. In the first step we systematically explore the object’s response by manipulating the amplitudes of the motors. This generates a pool of available moves (translations and rotations). We then calculate from this pool the most efficient way (either in terms of length or number of moves) to go from pose A to pose B using optimization strategies, such as genetic algorithms. The learning process may be repeated from time to time to account for changes in the mechanical response, at least for the patterns of vibration that contribute more to the change.
Prototype modules are made with eccentric rotating motors (type 345-002 Precision Microdrive) with a nominal force of 115g, which proved sufficient to shake (and eventually locomote) four-legged IKEA chairs and small furniture such as tables and stools. The motors are powered by NiMH batteries and communicate wirelessly with a low-cost ESP8266 WiFi module. The team designed modules that are externally attached using straps as well as motors embedded in furniture.
To study the general method, the team employed an overhead camera to track the chair and generate the pool of available moves. The team demonstrated that the system discovered pivot-like gaits and others. However, as one can imagine, using a pre-computed sequence to move to a target pose does not end up providing perfect matches. This is because the contact properties vary with location. Although this can be considered a secondary disturbance, it may in certain cases be mandatory to recompute the matrix of moves every now and then. The chair could, for instance, move into a wet area, over plastic carpet, etc.
The principle and application in furniture is called “ratchair” as a portmanteau combining “Ratchet” and “Chair”. Ratchair was demonstrated at the 2016 ACM Siggraph Emerging Technologies and won the DC-EXPO award jointly organized by the Japanese Ministry of Economy, Trade and Industry (METI) and the Digital Content Association of Japan (DCAJ). At the DCEXPO Exhibition, Fall 2016, the work was one of 20 Innovative Technologies and the only non-Japanese contribution.
*This article is from the KAIST Breakthroughs, research newsletter from the College of Engineering.
For more stories of the KAIST Breakthroughs, please visit http://breakthroughs.kaist.ac.kr
http://mid.kaist.ac.kr/projects/ratchair/
http://s2016.siggraph.org/content/emerging-technologies
https://www.dcexpo.jp/ko/15184
Figure 1. The vibration modules embedded and attached to furniture.
Figure 2. A close-up of the vibration module.
Figure 3. A close-up of the embedded modules.
Figure 4. A close-up of the vibration motor.
2017.03.23 View 8723 -
A Transport Technology for Nanowires Thermally Treated at 700 Celsius Degrees
Professor Jun-Bo Yoon and his research team of the Department of Electrical Engineering at KAIST developed a technology for transporting thermally treated nanowires to a flexible substrate and created a high performance device for collecting flexible energy by using the new technology.
Mr. Min-Ho Seo, a Ph.D. candidate, participated in this study as the first author. The results were published online on January 30th in ACS Nano, an international journal in the field of nanoscience and engineering. (“Versatile Transfer of an Ultralong and Seamless Nanowire Array Crystallized at High Temperature for Use in High-performance Flexible Devices,” DOI: 10.1021/acsnano.6b06842)
Nanowires are one of the most representative nanomaterials. They have wire structures with dimensions in nanometers. The nanowires are widely used in the scientific and engineering fields due to their prominent physical and chemical properties that depend on a one-dimensional structure, and their high applicability.
Nanowires have much higher performance if their structure has unique features such as an excellent arrangement and a longer-than-average length. Many researchers are thus actively participating in the research for making nanowires without much difficulty, analyzing them, and developing them for high performance application devices.
Scientists have recently favored a research topic on making nanowires chemically and physically on a flexible substrate and applies the nanowires to a flexible electric device such as a high performance wearable sensor.
The existing technology, however, mixed nanowires from a chemical synthesis with a solution and spread the mixture on a flexible substrate. The resultant distribution was random, and it was difficult to produce a high performance device based on the structural advantages of nanowires. In addition, the technology used a cutting edge nano-process and flexible materials, but this was not economically beneficial. The production of stable materials at a temperature of 700 Celsius degrees or higher is unattainable, a great challenge for the application.
To solve this problem, the research team developed a new nano-transfer technology that combines a silicon nano-grating board with a large surface area and a nano-sacrificial layer process. A nano-sacrificial layer exists between nanowires and a nano-grating board, which acts as the mold for the nano-transfer. The new technology allows the device undergo thermal treatment. After this, the layer disappears when the nanowires are transported to a flexible substrate.
This technology also permits the stable production of nanowires with secured properties at an extremely high temperature. In this case, the nanowires are neatly organized on a flexible substrate. The research team used the technology to manufacture barium carbonate nanowires on top of the flexible substrate. The wires secured their properties at a temperature of 700℃ or above. The team employed the collection of wearable energy to obtain much higher electrical energy than that of an energy collecting device designed based on regular barium titanate nanowires.
The researchers said that their technology is built upon a semiconductor process, known as Physical Vapor Deposition that allows various materials such as ceramics and semiconductors to be used for flexible substrates of nanowires. They expected that high performance flexible electric devices such as flexible transistors and thermoelectric elements can be produced with this method.
Mr. Seo said, “In this study, we transported nanowire materials with developed properties on a flexible substrate and showed an increase in device performance. Our technology will be fundamental to the production of various nanowires on a flexible substrate as well as the feasibility of making high performance wearable electric devices.”
This research was supported by the Leap Research Support Program of the National Research Foundation of Korea.
Fig. 1. Transcription process of new, developed nanowires (a) and a fundamental mimetic diagram of a nano-sacrificial layer (b)
Fig. 2. Transcription results from using gold (AU) nanowires. The categories of the results were (a) optical images, (b) physical signals, (c) cross-sectional images from a scanning electron microscope (SEM), and (d-f) an electric verification of whether the perfectly arranged nanowires were made on a large surface.
Fig. 3. Transcription from using barium titanate (BaTiO3) nanowires. The results were (a) optical images, (b-e) top images taken from an SEM in various locations, and (f, g) property analysis.
Fig. 4. Mimetic diagram of the energy collecting device from using a BaTiO3 nanowire substrate and an optical image of the experiment for the miniature energy collecting device attached to an index finger.
2017.03.22 View 8393 -
Professor Kwangjo Kim Named as Fellow of IACR
Professor Kwangjo Kim of the Graduate School of Information Security has been selected as a fellow of the International Association for Cryptologic Research (IACR).
The IACR has honored outstanding scholars who have achieved academic excellence in cryptologic research since 2004. He is the first Korean scholar to receive an IACR fellowship.
The IACR, established in 1981, is responsible for organizing international cryptologic conferences every year including the three major cryptologic academic conferences Eurocrypt, Crypto, and Asiacript. The IACR also sponsors workshop series such as the Theory of Cryptography Conference (TCC), the Workshop on Fast Software Encryption (FSE), the Public Key Cryptography Workshop (PKC), and Cryptographic Hardware and Embedded Systems (CHES).
Professor Kim, an internationally acclaimed scholar in the fields of cryptology and information security theory and its applications, was recognized for his outstanding academic achievements and leadership. He has made significant contributions to cryptology in Korea by hosting Asiacript in 1996 and 2001 as well as CHES in 2014. During his 34 years of academic activities, he has published more than 80 SCI journal papers and garnered more than 20,000 citations.
Professor Kim served on the board of the directors of the IACR from 2000 to 2004 and was the chairperson of the Asiacript Steering Committee from 2005 to 2008. He is on the editorial board of the online journal Cryptography.
Professor Kim said, “I am so humbled and honored to be named as a fellow of such a prestigious academic association. I will continue to strive to assist highly educated information security personnel with further research in cryptology.”
2017.03.16 View 7041 -
Global Workshop on the Risks of Emerging Technologies
The Center for Science, Policy and Society (CSPS) at the Graduate School of Science and Technology Policy of KAIST will host the 2017 Global Expert Workshop on the Risks of Emerging Technologies Driving the Fourth Industrial Revolution March 17-18 at the Plaza Hotel in Seoul.
At the workshop, experts from public and private sectors at home and abroad will address the socio-economic impacts and implications of the emergence of new technologies that the Fourth Industrial Revolution will bring about. The workshop will be hosted in collaboration with the World Economic Forum’s Global Future Council (GFC) on Technology, Values and Policy. The World Economic Forum’s network of GFCs is the world’s foremost interdisciplinary knowledge network dedicated to promoting innovative thinking about the future.
Four keynote speakers, including Professor Wendell Wallach of the Interdisciplinary Center for Bioethics at Yale University and Dean of the School of Public Policy and Management at Tsinghua University Lan Xue, will deliver speeches. Professor Wallach is the leader of an AI/Robotics Global Governance Project sponsored by the World Economic Forum and will make a speech entitled “Build the Global Infrastructure to Make Sure that AI and Robotics Will Be Beneficial.” Dean Xue, a member of the World Economic Forum’s GFC on Tech, Values, and Policy, is well known for his analysis of the social implications of the risks brought about by emerging technologies. He will speak on “Global Risk Governance of Disruptive 4IR Technologies.”
More than thirty experts will participate in the workshop. Speakers include the KAIST Vice President for Planning and Budget Soohyun Kim, Dean of KAIST Institute San Yup Lee, Professor Jaeseung Jeong of the Department of Bio and Brain Engineering at KAIST, Dr. Sung Chul Kang of the KIST Healthcare Robotics Research Group, and Korea Evaluation Institute of Industrial Technology Program Director Kyong Hoon Kim.
The CSPS of KAIST will continue to make collaborative research efforts with the GFC for developing new insights and perspectives on key global systems as well as study the impact and governance of key emerging technologies.
2017.03.16 View 8558 -
Dr.Sung-Chul Shin Inaugurated as the 16th President of KAIST
(President Shin delivers his inaugural address at the inauguration ceremony on March 15.)
Professor Sung-Chul Shin was officially inaugurated as its 16th president of KAIST on March 15 in a ceremony at the KAIST Auditorium.
The celebration began with a procession by dignitaries including the KAIST Board of Trustees Chairman Jang-Moo Lee, the National Academy of Sciences of Korea President Sook-Il Kwun, Daejeon City Mayor Sun-Taik Kwon, National Assemblyman Sangmin Lee, KAIST Alumni Association President Jungsik Koh. Academic leaders, foreign envoys, faculty, students, and staff members of KAIST joined the ceremony.
In his inaugural speech, President Shin presented a new vision for KAIST to become a global value creator in the Fourth Industrial Revolution. He said that KAIST has played a pivotal role in the nation’s industrialization and information revolution over the past half century and, with the advent of the new industry paradigm, KAIST should be now responsible for being a new value creator, not only serving the nation but pursuing global betterment. “KAIST should be a global hub of new knowledge and technology creation,” he emphasized.
Envisioning a “Global Value-Creative World-Leading University,” President Shin aims for KAIST to be an institution which can create global value as an innovative global leading research university. To realize this vision, he pledged to continue innovation in five areas of education, research & development, technology commercialization, globalization of the campus, and future strategy for the university and the nation.
In the educational innovation, he emphasized multidisciplinary studies, team work, and leadership training for students. To this end, KAIST will expand the non-departmental courses toward entire 4-year course while concurrently operating the existing system of declaring a major in students’ second year. KAIST will offer mandatory courses in humanities, social sciences, and arts and most classes will be run by team-based learning and group research activities. “KAIST Global Leadership Center” will support students to develop the qualities required for collaboration and the global leaderships.
With respect to the research innovation, President Shin said KAIST will establish “Convergence Research Matrix” system to foster strategic research groups for interdisciplinary and convergence collaboration across a wide range of divisions and departments. “Based on the CRMS, we will identify 10 flagship future-oriented convergence research areas for KAIST to truly claim its reputation as a world-leading research university,” he said. He added he will also introduce the “Collaborative Research Lab” system to better retain the academic successes without interruption, and to improve the continuity of research. “We will strive to organize teams of professors in diverse age groups to work together in mutually complementary fields,” he added.
In terms of technological commercialization, he hopes that KAIST to be a role model. He said he will make every effort to establish a resilient R&DB environment with ideas, technologies, and entrepreneurship. KAIST will rev up a new university-industry cooperation, fully sponsoring the creation of “Technology in-Kind Investment Companies.”
KAIST will continue to take initiative for globalization. He said KAIST will create an ‘English-Only Zone’ at the campus, saying that his ultimate goal is to create Korean-English bilingual campus. He also asked the foreign community to make their effort to learn Korean and Korean culture while staying at KAIST, in an effort to embrace diversity at the campus. He plans to increase the ratio of foreign faculty from nine percent to 15 percent, while doubling the current foreign student enrollment ratio of five percent.
As for the future strategy for the university and the nation, he will soon finalize the long-term strategic plan of “Vision 2031” that will lay out a roadmap for KAIST future direction toward its 60th anniversary. KAIST will also play a fundamental role in shaping national policies and strategies for science and technology by operating think-tank groups that consist of KAIST beyond disciplines. These think-tanks will design detailed development plans for KAIST as well as for national strategies for the advancement of science and technology.
He said that such institutional innovation will not be completed without the support, dedication, and passion of all KAIST members, adding that he will strive to serve them with 3Cs (Change, Communication, and Care).
For the full text of President Shin’s inaugural address, please click.
2017.03.15 View 9289 -
Quantum Dot Film Can Withstand High Temperatures and Humidity
The joint KAIST research team of Professor Byeong-Soo Bae of the Department of Materials Science and Engineering and Professor Doh Chang Lee of the Department of Chemical and Biomolecular Engineering was able to fabricate a siloxane-encapsulated quantum dot film, which exhibits stable emission intensity over one month even at high temperatures and humidity.
The results of this study were published in the Journal of the American Chemical Society (JACS) on November 29, 2016. The research article is entitled “Quantum Dot/Siloxane Composite Film Exceptionally Stable against Oxidation under Heat and Moisture.” (DOI: 10.1021/jacs.6b10681)
Quantum dots (QDs), light-emitting diodes (LEDs) for next-generation displays, are tiny particles or nanocrystals of semiconducting materials. Their emission wavelength can easily be adjusted by changing their sizes, which are just a few nanometers. A wide spectrum of their colors can also achieve ultra-high definition displays.
Due to these characteristics, QDs are coated on a film as a polymer resin in dispersed form, or they are spread on an LED light source. They are thus considered to be crucial for next generation displays.
Despite their exceptional optical properties, however, QDs are easily oxidized in a high temperature and high humidity environment, and, as a result, this greatly deteriorates their luminescence quality (quantum efficiency). Therefore, they are encapsulated in an extra thin layer to block oxygen and moisture.
QD displays in the current market have a film inserted to separate them from LEDs, which create heat. The high unit cost of this protective layer, however, increases the overall cost of displays, lowering their price competitiveness in the market.
For a solution, the research team applied the sol-gel condensation reaction of silane precursors with QDs. This technology uses the reactions of chemical substances to synthesize ceramics or glass at a low temperature.
The team applied QDs in a heat resistant siloxane polymer by employing this technology. The siloxane resin acted as a cup holding the QDs and also blocked heat and moisture. Thus, their performance can be maintained without an extra protective film.
QDs are evenly dispersed into the resin from a chemical process to fabricate a QD embedded film and retained the high quality luminescence not only at a high temperature of 85°C and in a high humidity of 85%, but also in a high acid and high base environment. Remarkably though, the luminescence actually increased in the high humidity environment.
If this technology is used, the overall price of displays will decrease by producing a stable QD film without an extra protective barrier. In the future, the QD film can be directly applied to a blue LED light source. As a result, it will be possible to develop a QD display that can reduce the amount of QDs needed and improve its performance.
Professor Bae said, “We have proposed a way to make quantum dots overcome their limitations and have wide applications as they are being developed for next-generation displays. Our technology will make significant contributions to the display industry in the country.”
He also added, “In the future, we plan to cooperate with companies both in and out of the country to improve the performance of quantum dots and concentrate on their commercialization.”
The research team is currently applying for related patents both in and out of the country. The team is also plan ning to transfer the patents to Sol Ip Technology Inc., a company founded at KAIST, to start the commercialization.
Picture 1:
Siloxane-encapsulated quantum dot (QD) films showing performance stability in boiling water
Picture 2 and 3:
So-gel condensation reaction in silane precursors between Methacryloxypropyltrimethoxysilane (MPTS) and diphenylsilanediol (DPSD). The inset shows photographs of a QD-oligosiloxane resin under room light (left) and a UV lamp (λ = 365 nm) (right).
Free radical addition reactions among carbon double bonds of methacryl functional groups and oleic acids. The inset shows photographs of a QD-silox film under room light (left) and a UV lamp (λ = 365 nm) (right).
2017.02.24 View 9488 -
Dr. Sung-Chul Shin Selected 16th President of KAIST
(President Sung-Chul Shin)
The KAIST Board of Trustees elected Professor Sung-Chul Shin of the Department of Physics the 16th president of KAIST on February 21. Professor Shin succeeds President Sung-Mo Kang whose four-year term will end on February 23. He is the first KAIST alumnus to serve as its president.
The Board of Trustees announced, “We believe that Professor Shin’s scientific achievement, outstanding leadership, and clear vision will serve KAIST faculty, students, and staff very well. He will be the best person to help KAIST leap forward in the four years ahead.”
The newly-elected president said, “I am humbled and honored to have been elected to lead such a prestigious institute of Korea. Aiming to be one of the top ten global universities, KAIST will continue to innovate its systems.” Previously, Dr. Shin led the Daegu Gyeongbuk Institute of Science and Technology (DGIST) for six years as president since 2011.
Professor Shin joined the KAIST faculty in 1989. He graduated from Seoul National University and then earned his MS degree in condensed matter physics at KAIST in 1977. After earning his Ph.D. in material physics at Northwestern University in 1984, he worked at Eastman Kodak Research Labs as a senior research scientist for five years.
Before heading to DGIST, President Shin held key administrative positions at KAIST from the early 1990s including dean of planning, dean of the international office, and vice-dean of student affairs. During President Robert Laughlin’s tenure, the first foreign president at KAIST, he served as vice-president for two years from 2004. He also served on the Presidential Advisory Council on Science and Technology of the Korean government as vice chairperson from 2015 to 2016.
A renowned scholar in the field of nanoscience, President Shin’s research focuses on the artificial synthesis and characterization of nonmagnetic materials, magnetic anisotropy, and magneto-optical phenomena. He leads the Laboratory for Nanospinics of Spintronic Materials at KAIST and has published in 290 journals while holding 37 patents.
A fellow in the American Physical Society (APS) since 2008, he was the president of the Korean Physical Society from 2011 to 2012. He has been on the editorial board of J. Magnetism and Magnetic Materials from 2009 and was the first Korean recipient of the Asian Union of Magnetics Societies (AUMS) Award, which recognizes outstanding scientists in the field of magnetics.
President Shin envisions making KAIST’s research and education more competitive through continuing innovation. His innovation efforts will extend to the five key areas of education, research, technology commercialization, globalization, and future planning.
Among his priorities, he emphasizes multidisciplinary studies and leadership training for students. He plans to focus on undeclared major courses for undergraduates to help them expand their experience and exposure to diverse disciplines. This approach will help create well-rounded engineers, scientists, and entrepreneurs by enabling them to develop skills while leveraging a strong connection to the arts, humanities, and social sciences.
To better respond to Industry 4.0, which calls for convergence studies and collaborative work, he proposed establishing a ‘Convergence Innovation System’ by strategically selecting 10 flagship convergence research groups. In order to accelerate the technology commercialization and ecosystem of start-ups, he will strengthen entrepreneurship education, making it a prerequisite requirement for students. President Shin said he will spare no effort to incubate and spin-off ventures in which KAIST technology is being transferred. For globalization efforts, he plans to increase the ratio of foreign faculty from 9 percent to 15 percent, while doubling the current foreign student enrollment ratio of 5 percent. For future strategic innovation, he will implement a long-term innovation strategic plan dubbed ‘Vision 2031.’
2017.02.22 View 9388 -
Controlling Turtle Motion with Human Thought
KAIST researchers have developed a technology that can remotely control an animal’s movement with human thought.
In the 2009 blockbuster “Avatar,” a human remotely controls the body of an alien. It does so by injecting human intelligence into a remotely located, biological body. Although still in the realm of science fiction, researchers are nevertheless developing so-called ‘brain-computer interfaces’ (BCIs) following recent advances in electronics and computing. These technologies can ‘read’ and use human thought to control machines, for example, humanoid robots.
New research has demonstrated the possibility of combining a BCI with a device that transmits information from a computer to a brain, or known as a ‘computer-to-brain interface’ (CBI). The combination of these devices could be used to establish a functional link between the brains of different species. Now, researchers from the Korea Advanced Institute of Science and Technology (KAIST) have developed a human-turtle interaction system in which a signal originating from a human brain can affect where a turtle moves.
Unlike previous research that has tried to control animal movement by applying invasive methods, most notably in insects, Professors Phill-Seung Lee of the Mechanical Engineering Department and Sungho Jo of the Computing School propose a conceptual system that can guide an animal’s moving path by controlling its instinctive escape behavior. They chose a turtle because of its cognitive abilities as well as its ability to distinguish different wavelengths of light. Specifically, turtles can recognize a white light source as an open space and so move toward it. They also show specific avoidance behavior to things that might obstruct their view. Turtles also move toward and away from obstacles in their environment in a predictable manner. It was this instinctive, predictable behavior that the researchers induced using the BCI.
The entire human-turtle setup is as follows: A head-mounted display (HMD) is combined with a BCI to immerse the human user in the turtle’s environment. The human operator wears the BCI-HMD system, while the turtle has a 'cyborg system'—consisting of a camera, Wi-Fi transceiver, computer control module, and battery—all mounted on the turtle’s upper shell. Also included on the turtle’s shell is a black semi-cylinder with a slit, which forms the ‘stimulation device.’ This can be turned ±36 degrees via the BCI.
The entire process works like this: the human operator receives images from the camera mounted on the turtle. These real-time video images allow the human operator to decide where the turtle should move. The human provides thought commands that are recognized by the wearable BCI system as electroencephalography (EEG) signals. The BCI can distinguish between three mental states: left, right, and idle. The left and right commands activate the turtle’s stimulation device via Wi-Fi, turning it so that it obstructs the turtle’s view. This invokes its natural instinct to move toward light and change its direction. Finally, the human acquires updated visual feedback from the camera mounted on the shell and in this way continues to remotely navigate the turtle’s trajectory.
The research demonstrates that the animal guiding scheme via BCI can be used in a variety of environments with turtles moving indoors and outdoors on many different surfaces, like gravel and grass, and tackling a range of obstacles, such as shallow water and trees. This technology could be developed to integrate positioning systems and improved augmented and virtual reality techniques, enabling various applications, including devices for military reconnaissance and surveillance.
***
Reference: “Remote Navigation of Turtle by Controlling Instinct Behavior via Human Brain-computer Interface,” Journal of Bionic Engineering, July 2016 (DOI: 10.1016/S1672-6529(16)60322-0)
Depiction of Cyborg System
A human controller influences the turtle’s escape behavior by sending left and right signals via Wi-Fi to a control system on the back of the turtle.
2017.02.21 View 13810 -
Professor Shin Honored Posthumously for Iridescent Microparticles
(The Late Professor Joong-Hoon Shin (left) and Professor Shin-Hyun Kim)
A research team co-led by Professor Shin-Hyun Kim from the Department of Chemical and Biomolecular Engineering and Professor Jong-Ryul Jeong from the Department of Materials Science and Engineering at Chungnam National University developed iridescent microparticles with a structural color gradient. The research team posthumously dedicated their research to a renowned professor in the field of nanophotonics, the late Professor Joong-Hoon Shin of the Graduate School of Nanoscience and Technology at KAIST. He passed away suddenly in a car accident last September.
The iridescent microparticles, which allow on-demand control over structural color, will be key components for next-generation reflection-mode displays with clear color realization even in direct sunlight.
Materials such as opals, Morpho butterfly wings, and peacock feathers all display beautiful colors without pigment, using regularly-spaced nanostructures. Regularly-spaced nanostructures render color, by selectively reflecting the light of a particular wave through light interference. As such, materials that possess periodic modulation of refractive index at subwavelength scale are referred to as photonic crystals.
In general, photonic crystals are only able to display a single color, so limitations exist when attempting to apply them to reflection-mode displays which call for multiple structural colors. The research team addressed the issue using inspiration from snowflakes stacking in the winter. When snow falls on the surface of a round-shaped structure, the thickness of the snow stacking differs depending on the orientation. Based on this observation, the research team created photonic microparticles with a structural color gradient by depositing two different materials on spherical microparticles.
When some material is deposited on the surface of a sphere, the material on the top is thickest and becomes thinner on the sides. The team alternately deposited titania and silica on the spherical microparticles to form periodic modulation of the refractive index. The thickness of the alternating photonic layers is reduced along the angle from the top, which yields a structural color gradient.
Consequently, the microparticles reflect long-wavelength red light from the top of the sphere and short-wavelength blue light from the side of the sphere. Any color of the visible spectrum can be selected in between the top and side depending on the orientation of the microparticles.
The research team used an external magnetic field as a way to control the orientation of the photonic microparticles and the structural colors. As magnetic iron layer was deposited underneath the alternating photonic layer, it was possible to freely control the orientation of the microparticles using a magnet, thereby allowing control of the color seen by the users.
KAIST doctoral candidate Seung Yeol Lee of the Department of Chemical and Biomolecular Engineering is the first author of this research, with support from the Midcareer Researcher Program of the National Research Foundation and funded by the Ministry of Science, ICT, and Future Planning (MSIP). This research was published in the online edition of Advanced Materials on February 6, 2017.
Figure1: Sets of an OM image of photonic Janus microspheres and an SEM image showing a cross-section of the photonic layers.
Figure 2: A series of schematics and OM images showing the color change depending on the orientation angle of the photonic Janus microsphere.
2017.02.17 View 8048 -
An Improved Carbon Nanotube Semiconductor
Professor Yang-Kyu Choi and his research team of the School of Electrical Engineering at KAIST collaborated with Professor Sung-Jin Choi of Kookmin University to develop a large-scale carbon nanotube semiconductor by using a 3-D fin-gate structure with carbon nanotubes on its top.
Dong Il Lee, a postdoctoral researcher at KAIST’s Electrical Engineering School, participated in this study as the first author. It was published in ACS Nano on November 10, 2016, and was entitled “Three-Dimensional Fin-Structured Semiconducting Carbon Nanotube Network Transistor.”
A semiconductor made with carbon nanotubes operates faster than a silicon semiconductor and requires less energy, yielding higher performance.
Most electronic equipment and devices, however, use silicon semiconductors because it is difficult to fabricate highly purified and densely packed semiconductors with carbon nanotubes (CNTs).
To date, the performance of CNTs was limited due to their low density. Their purity was also low, so it was impossible to make products that had a constant yield on a large-surface wafer or substrate. These characteristics made the mass production of semiconducting CNTs difficult.
To solve these difficulties, the research team used a 3-D fin-gate to vapor-deposit carbon nanotubes on its top. They developed a semiconductor that had a high current density with a width less than 50 nm.
The three-dimensional fin structure was able to vapor-deposit 600 carbon nanotubes per micrometer. This structure could have 20 times more nanotubes than the two dimensional structure, which could only vapor-deposit thirty in the same 1 micrometer width.
In addition, the research team used semi-conductive carbon nanotubes having a purity rating higher than 99.9% from a previous study to obtain a high yield semiconductor.
The semiconductor from the research group has a high current density even with a width less than 50 μm. The new semiconductor is expected to be five times faster than a silicon-based semiconductor and will require five times less electricity during operation.
Furthermore, the new semiconductor can be made by or will be compatible with the equipment for producing silicon-based semiconductors, so there will be no additional costs.
Researcher Lee said, “As a next generation semiconductor, the carbon nanotube semiconductor will have better performance, and its effectiveness will be higher.” He also added, “Hopefully, the new semiconductor will replace the silicon-based semiconductors in ten years.”
This study received support from the Center for Integrated Smart Sensors funded by the Ministry of Science, ICT & Future Planning of Korea as the Global Frontier Project, and from the CMOS (Complementary Metal-Oxide-Semiconductor) THz Technology Convergence Center of the Pioneer Research Center Program sponsored by the National Research Foundation of Korea.
Picture 1: 3D Diagram of the Carbon Nanotube Electronic Device and Its Scanning Electron Microscope (SEM) Image
Picture 2: 3D Transistor Device on an 8-inch Base and the SEM Image of Its Cross Section
2017.02.16 View 9638