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Research Day Highlights Most Outstanding Research Achievements
Professor Byung Jin Cho from the School of Electrical Engineering was selected as the Grand Research Prize Winner in recognition of his innovative research achievement in the fields of nano electric and flexible energy devices during the 2019 KAIST Research Day ceremony held on April 23 at the Chung Kunmo Conference Hall. The ten most outstanding research achievements from the past year were also awarded in the three areas of Research, Innovation, Convergence Researches. Professor Cho is an internationally recognized researcher in the field of future nano and energy device technology. Professor Cho’s team has continued to research on advanced CMOS (complementary metal-oxide semiconductors). CMOS has become his key research topic over the past three decades. In 2014, he developed a glass fabric-based thermoelectric generator, which is extremely light and flexible and produces electricity from the heat of the human body. It is so flexible that the allowable bending radius of the generator is as low as 20 mm. There are no changes in performance even if the generator bends upward and downward for up to 120 cycles. His wearable thermoelectric generator was selected as one of the top ten most promising digital technologies by the Netexplo Forum in 2015. He now is working on high-performance and ultra-flexible CMOS IC for biomedical applications, expanding his scope to thermal haptic technology in VR using graphene-CMOS hybrid integrated circuits; to self-powered wireless sensor nodes and self-powered ECG system using wearable thermoelectric generators . In his special lecture at the ceremony, Professor Cho stressed the importance of collaboration in making scientific research and presented how he moved to future devices after focusing on scaling the devices. “When I started the research on semiconductors, I focused on how to scale the device down as much as possible. For decades, we have conducted a number of procedures to produce tiny but efficient materials. Now we have shifted to develop flexible thermoelements and wearable devices,” said Professor Cho. “We all thought the scaling down is the only way to create value-added technological breakthroughs. Now, the devices have been scaled down to 7nm and will go down to 5 nm soon. Over the past few years, I think we have gone through all the possible technological breakthroughs for reducing the size to 5nm. The semiconductor devices are made of more 1 billion transistors and go through 1,000 technological processes. So, there won’t be any possible way for a single genius to make a huge breakthrough. Without collaboration with others, it is nearly impossible to make any new technological breakthroughs.” Professor Cho has published more than 240 papers in renowned academic journals and presented more than 300 papers at academic conferences. He has also registered approximately 50 patents in the field of semiconductor device technology. The top ten research highlights of 2018 as follows: - Rydberg-Atom Quantum Simulator Development by Professor Jaewook Ahn and Heung-Sun Sim from the Department of Physics - From C-H to C-C Bonds at Room Temperature by Professor Mu-Hyun Baik from the Department of Chemistry - The Role of Rodlike Counterions on the Interactions of DNAs by Professor Yong Woon Kim of the Graduate School of Nanoscience and Technology - The Medal Preoptic Area Induces Hunting-Like Behaviors to Target Objects and Prey by Professor Daesoo Kim from the Department of Biological Sciences - Identification of the Origin of Brain Tumors and New Therapeutic Strategy by Professor Jeong Ho Lee from the Graduate School of Medical Science and Engineering - The Linear Frequency Conversion of Light at a Spatiotemporal Boundary by Professor Bumki Min from the Department of Mechanical Engineering - An Industrial Grade Flexible Transparent Force Touch Sensor by Professor Jun-Bo Yoon from the School of Electrical Engineering - The Detection and Clustering of Mixed-Type Defect Patterns in Wafer Bin Maps by Professor Heeyoung Kim from the Department of Industrial and Systems Engineering - The Development of a Reconfigurable Spin-Based Logic Device by Professor Byong-Guk Park from the Department of Materials Science and Engineering - The Development of a Miniaturized X-Ray Tube Based on Carbon Nanotube and Electronic Brachytherapy Device by Professor Sung Oh Cho from the Department of Nuclear and Quantum Engineering Professor YongKeun Park from the Department of Physics and Professor In-Chel Park from the School of Electrical Engineering received the Research Award. For the Innovation Award, Professor Munchurl Kim from the School of Electrical Engineering was the recipient and the Convergence Research Awards was conferred to Professor Sung-Yool Choi from the School of Electrical Engineering, Professor Sung Gap Im from the Department of Chemical and Biomolecular Engineering, and Professor SangHee Park from the Department of Materials Science and Engineering during the ceremony. For more on KAIST’s Top Research Achievements and Highlight of 2018, please refer to the attached below. click.
2019.04.25
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KAIST Unveils the Hidden Control Architecture of Brain Networks
(Professor Kwang-Hyun Cho and his team) A KAIST research team identified the intrinsic control architecture of brain networks. The control properties will contribute to providing a fundamental basis for the exogenous control of brain networks and, therefore, has broad implications in cognitive and clinical neuroscience. Although efficiency and robustness are often regarded as having a trade-off relationship, the human brain usually exhibits both attributes when it performs complex cognitive functions. Such optimality must be rooted in a specific coordinated control of interconnected brain regions, but the understanding of the intrinsic control architecture of brain networks is lacking. Professor Kwang-Hyun Cho from the Department of Bio and Brain Engineering and his team investigated the intrinsic control architecture of brain networks. They employed an interdisciplinary approach that spans connectomics, neuroscience, control engineering, network science, and systems biology to examine the structural brain networks of various species and compared them with the control architecture of other biological networks, as well as man-made ones, such as social, infrastructural and technological networks. In particular, the team reconstructed the structural brain networks of 100 healthy human adults by performing brain parcellation and tractography with structural and diffusion imaging data obtained from the Human Connectome Project database of the US National Institutes of Health. The team developed a framework for analyzing the control architecture of brain networks based on the minimum dominating set (MDSet), which refers to a minimal subset of nodes (MD-nodes) that control the remaining nodes with a one-step direct interaction. MD-nodes play a crucial role in various complex networks including biomolecular networks, but they have not been investigated in brain networks. By exploring and comparing the structural principles underlying the composition of MDSets of various complex networks, the team delineated their distinct control architectures. Interestingly, the team found that the proportion of MDSets in brain networks is remarkably small compared to those of other complex networks. This finding implies that brain networks may have been optimized for minimizing the cost required for controlling networks. Furthermore, the team found that the MDSets of brain networks are not solely determined by the degree of nodes, but rather strategically placed to form a particular control architecture. Consequently, the team revealed the hidden control architecture of brain networks, namely, the distributed and overlapping control architecture that is distinct from other complex networks. The team found that such a particular control architecture brings about robustness against targeted attacks (i.e., preferential attacks on high-degree nodes) which might be a fundamental basis of robust brain functions against preferential damage of high-degree nodes (i.e., brain regions). Moreover, the team found that the particular control architecture of brain networks also enables high efficiency in switching from one network state, defined by a set of node activities, to another – a capability that is crucial for traversing diverse cognitive states. Professor Cho said, “This study is the first attempt to make a quantitative comparison between brain networks and other real-world complex networks. Understanding of intrinsic control architecture underlying brain networks may enable the development of optimal interventions for therapeutic purposes or cognitive enhancement.” This research, led by Byeongwook Lee, Uiryong Kang and Hongjun Chang, was published in iScience (10.1016/j.isci.2019.02.017) on March 29, 2019. Figure 1. Schematic of identification of control architecture of brain networks. Figure 2. Identified control architectures of brain networks and other real-world complex networks.
2019.04.23
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'In KAIST, Administration Should Be Done Scientifically Too'
A university community is comprised of three actors; student, faculty, and staff members. Among them, in many cases, the staff remain the hidden group, always working behind the spotlight. However, the final pieces of the puzzle always go through the hands of staff members who facilitate students’ and faculty members’ studies and research. The Office of Administration recently published two books: “In KAIST, Administration Should Be Done Scientifically Too,” and “A Life of Staff Called K.” The books describe ways to propel administrative innovation and organizational changes, seeking to increase the value of staff members’ working scope and their professionalism. These are the result of the 43-member Administration Advancement Committee’s year-long research to improve institutional efficiency. The 43 staff members voluntarily participated in the publication. The books cite “the independent and self-motivating administration" as an ideal environment to make professional staff members. And the institution is responsible for creating such an inspiring environment through innovation. “This will highlight the guiding role of our 550 staff members, who are at the frontline serving students and faculty. Based on the analysis of these valuable books, we will provide various educational systems and revise current HR system to enhance our staff’s career performance,” says Ki-Han Kim, Associate Vice President of Administration. According to “In KAIST, Administration Should Be Done Scientifically Too,” 48% of students and faculty expressed negativity regarding the staff members’ performance in the administration offices. Meanwhile about 50% of them expressed satisfaction for the services provided by their department offices. The book analyzed which side current administration system should address more. The book reports that 55% of staff members also cited professionalism as a priority for their career building. However, 65% of them confessed that they rarely have strong sense of ownership, which leads to passive working performance. Despite such passive attitude, 84% of them showed strong fellowship with their colleagues, a promising signal to the future administrative services and systems. These books identify four prescriptions for advancing administration services: improving the HR system, building professionalism, establishing smart working systems, and creating an efficient organizational culture.
2019.04.23
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Professor Ji-Hyun Lee Awarded the Sasada Prize
Professor Ji-Hyun Lee from the Graduate School of Culture Technology was awarded the Sasada Prize during the 24th annual Conference of Computer-Aided Architectural Design Research in Asia (CAADRIA) held in Wellington, New Zealand on April 15. The Sasada Award honors the late Professor Tsuyoshi Sasada (1941-2005), the former Professor of Osaka University and co-founder and fellow of CAADRIA. It is given to an individual who has contributed to the next generation of researchers and academics, to the wider profession and practice in computer-aided design and research, and has earned recognition in the academic community. Professor Lee was recognized for her development of CAAD (Computer-Aided Architectural Design) through her research work on the land price precision system using case-based reasoning. Her research team proposed a model for estimating the average apartment price in an administrative district after collecting 40 variables from the six major Korean cities, excluding Seoul and Ulsan. Their follow-up studies showed the possibility of replacing existing experts’ predictions. Professor Lee has been steadily researching for 20 years on case-based reasoning (CBR), a field of artificial intelligence, and has published more than 40 papers in the field of CBR. Meanwhile, the CAAD Future 2019 event will be held at KAIST in June.
2019.04.23
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On-chip Drug Screening for Identifying Antibiotic Interactions in Eight Hours
(from left: Seunggyu Kimand Professor Jessie Sungyun Jeon) A KAIST research team developed a microfluidic-based drug screening chip that identifies synergistic interactions between two antibiotics in eight hours. This chip can be a cell-based drug screening platform for exploring critical pharmacological patterns of antibiotic interactions, along with potential applications in screening other cell-type agents and guidance for clinical therapies. Antibiotic susceptibility testing, which determines types and doses of antibiotics that can effectively inhibit bacterial growth, has become more critical in recent years with the emergence of antibiotic-resistant pathogenic bacteria strains. To overcome the antibiotic-resistant bacteria, combinatory therapy using two or more kinds of antibiotics has been gaining considerable attention. However, the major problem is that this therapy is not always effective; occasionally, unfavorable antibiotic pairs may worsen results, leading to suppressed antimicrobial effects. Therefore, combinatory testing is a crucial preliminary process to find suitable antibiotic pairs and their concentration range against unknown pathogens, but the conventional testing methods are inconvenient for concentration dilution and sample preparation, and they take more than 24 hours to produce the results. To reduce time and enhance the efficiency of combinatory testing, Professor Jessie Sungyun Jeon from the Department of Mechanical Engineering, in collaboration with Professor Hyun Jung Chung from the Department of Biological Sciences, developed a high-throughput drug screening chip that generates 121 pairwise concentrations between two antibiotics. The team utilized a microfluidic chip with a sample volume of a few tens of microliters. This chip enabled 121 pairwise concentrations of two antibiotics to be automatically formed in only 35 minutes. They loaded a mixture of bacterial samples and agarose into the microchannel and injected reagents with or without antibiotics into the surrounding microchannel. The diffusion of antibiotic molecules from the channel with antibiotics to the one without antibiotics resulted in the formation of two orthogonal concentration gradients of the two antibiotics on the bacteria-trapping agarose gel. The team observed the inhibition of bacterial growth by the antibiotic orthogonal gradients over six hours with a microscope, and confirmed different patterns of antibiotic pairs, classifying the interaction types into either synergy or antagonism. Professor Jeon said, “The feasibility of microfluidic-based drug screening chips is promising, and we expect our microfluidic chip to be commercialized and utilized in near future.” This study, led by Seunggyu Kim, was published in Lab on a Chip (10.1039/c8lc01406j) on March 21, 2019. Figure 1. Back cover image for the “Lab on a Chip”. Figure 2. Examples of testing results using the microfluidic chips developed in this research.
2019.04.18
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A Hole in One for Holographic Display
(Professor YongKeun Park) Researchers have designed an ultrathin display that can project dynamic, multi-coloured, 3D holographic images, according to a study published in Nature Communications. The system’s critical component is a thin film of titanium filled with tiny holes that precisely correspond with each pixel in a liquid crystal display (LCD) panel. This film acts as a ‘photon sieve’ – each pinhole diffracts light emerging from them widely, resulting in a high-definition 3D image observable from a wide angle. The entire system is very small: they used a 1.8-inch off-the-shelf LCD panel with a resolution of 1024 x 768. The titanium film, attached to the back of the panel, is a mere 300 nanometres thick. “Our approach suggests that holographic displays could be projected from thin devices, like a cell phone,” says Professor YongKeun Park, a physicist at KAIST who led the research. The team demonstrated their approach by producing a hologram of a moving, tri-coloured cube. Specifically, the images are made by pointing differently coloured laser beams made of parallel light rays at the small LCD panel. The photon sieve has a hole for each pixel in the LCD panel. The holes are precisely positioned to correspond to the pixel’s active area. The pinholes diffract the light emerging from them, producing 3D images. Previous studies from Professor Park’s group have used optical diffusors for the same purpose, but the size of the device was bulky and difficult to be operated, and it took a long period of time to calibrate. In the present work, on the other hand, the group tailored their photon sieve to demonstrate a simple, compact and scalable method for 3D holographic display. This technique can be readily applied to existing LCD displays. Applications for holograms have been limited by cumbersome techniques, high computation requirements, and poor image quality. Improving current techniques could lead to a wide variety of applications, including 3D cinema viewing without the need for glasses, watching holographic videos on television and smart phone screens. Figure 1. The actual 3D holographic display, and an electron microscope image of the non-periodic pinholes. Figure 2. Three-dimensional dynamic color hologram operating at 60 Hz
2019.04.18
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Next-Generation Small Satellite Starts Operations
Korea’s next generation small satellite developed by KAIST started its space observation missions after completing its performance checkup, the Ministry of Science and ICT announced on April 16. The Ministry said that the Next Sat-1, launched on Dec. 4, has successfully deployed its solar panels, adjusted its posture and carried out internal checks to see if all system were functioning normally. The Next Sat-1, expected to be operation for some two years, is the first locally made satellite to have instruments for the Study of Space Storms (ISSS) that can check the impact of solar storms on the magnetic field of the pole areas. It can be further used to detect changes to the Earth's ionosphere in low longitude regions. The ministry said the satellite's near-infrared imaging spectrometer (NISS) camera will be used to peer into space with one of tasks to determine the brightness of the M95 barred spiral galaxy in the constellation Leo. KAIST built the large capacity memory and communication equipment with others, like Asia Pacific Satellite Inc., building star tracking sensors, computers and high speed data processors specifically designed for space. The satellite weighs 100 kg and is in orbit 575 km from the surface of the Earth. “Everything has been checked to be in working order with initial tests utilizing its sensors and camera revealing positive results,” the Ministry said in a statement. (Yonhap News) (The photos shows details of the Next Sat-1 satellite.)
2019.04.16
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Chair Professor Seong Honored with Don Miller Award
(Professor Poong-Hyun Seong) Chair Professor Poong-Hyun Seong from the Department of Nuclear & Quantum Engineering was selected as the recipient of the Don Miller Award by the American Nuclear Society. The award, established in 2009 by the American Nuclear Society in honor of former ANS President Don Miller, is given to an individual or team who has made a significant contribution to the advancement of one or both of the fields of nuclear instrumentation and control of human-machine interfaces through individual or combined activities. The award ceremony will be held on June 10 during the 2019 annual meeting of the ANS in Minneapolis in the US. Professor Seong is being recognized for his pioneering research and training in the fields of nuclear instrumentation control and human factor engineering at Korea. His research significantly contributed to safety improvements in nuclear power plants and have been recognized worldwide. Professor Seong, a fellow of the ANS, now serves as the first vice chair of the International Nuclear Societies Council and will take up the role of chair in 2021. Professor Seong said that, “ Korea is one of the most outstanding countries working on research in the fields of nuclear instrumentation control and human factors. KAIST PhDs are teaching at many universities at home and abroad. I look forward this award bringing new hope to our nuclear research and the domestic nuclear industry, which is now in difficult times.”
2019.04.11
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KAIST-THE Innovation & Impact Summit Touts New Roles of Higher Education
Global leaders from 115 institutions across 35 countries reaffirmed that the roles of universities are evolving to become much broader and more diverse, and redefined the impact of higher education last week at KAIST. During the THE Innovation and Impact Summit hosted by KAIST in partnership with the Times Higher Education, global leaders in higher education, industry, and government all agreed that universities should respond better in order to have a lasting and sustainable impact on society. In an effort to encourage social responsibility and boost the impact of universities, the THE first launched the University Impact Rankings based on the Sustainable Developed Goals declared during the 2015 UN summit. The THE’s University Impact Rankings are the first global attempt to evaluate universities’ impact on society, rather than only focusing on research and teaching performance. The new metrics include universities’ policies and outcomes based on 11 of the 17 UN SDGs. More than 500 institutions from 75 countries submitted data for the new rankings. The top three scores from ten of the SDGs were combined with SDG 17 to calculate the final score. The University of Auckland placed first in this new ranking while KAIST ranked fourth in the category of SDG 9 on Industry, Innovation, and Infrastructure. President Shin said, “KAIST has dedicated itself to producing knowledge that could serve as a growth engine for national development over the past half century. Now, taking on the UN’s 17 SDGs as new indicators, we will do our utmost to become a leading university in creating global value and better serving the world.” (Phil Baty, chief knowledge officer of THE) Phil Baty, chief knowledge officer at THE said, “I would like to applaud KAIST for being a pioneer, taking a new way of looking at university excellence. KAIST’s performance was strong overall, but especially outstanding in SDG 9. Its data proves that the university is fully engaged in knowledge creation and entrepreneur activities.” Keynote speakers all shared their views on disruptive knowledge and how to adjust to the new AI technology-driven, socio-economic culture. (from left: Lino Guzzella, former ETH Zurich President and Sung-Chul Shin, KAIST President) Lino Guzzella, former ETH Zurich President, argued in his keynote speech that there has been amazing growth in university enrollments, coupled with a substantial mismatch between what universities teach and what society needs. He went on to say that universities should look beyond the classical university model and find a way to train the next generation in a way that ensures society has a role for them. “The likelihood of each generation having a higher income at the age of 30 than their parents has diminished dramatically,” he said. He provided data that showed that middle-income professions have been declining, and between 2000 and 2010 the number of very high-skilled jobs and very low-skilled jobs doubled, whereas the number of those in the middle increased far more slowly. He expected that this trend will continue, saying that universities should focus on instilling critical thinking, interdisciplinary studies, and ‘productive failure’ to students in the new era. He also shared the secret recipe for the reduced youth unemployment statistics in Switzerland. He said that the education system in Switzerland was designed so that only 20 percent of an age cohort undertakes a classical university education, while 80 percent do vocational training run by companies. They learn what is really needed by industry and society from the early stages of their careers, so no mismatch exists. (Young Suk Chi, chairman of Elsevier) Meanwhile, Young Suk Chi, chairman of Elsevier, claimed in his keynote speech that universities should stop evaluating researchers only on their publication and citation counts. He said that doing so was driving academics to turn out multiple papers based on a single study in a practice called ‘salami publishing.’ Chi said, “It’s a responsibility we bear together, and we certainly, as industry associates, have to work hard to educate the world that publishing isn’t everything, but the impact is. But the impact is not just citations, either.” Chi said that there is a global ‘tech-lash’ that has arisen due to falling trust in major IT companies. On the other hand, universities are trustworthy. People perceive that universities are not merely seeking profits, and they can take advantage of it for fostering next generation researchers and CEOs, which can stand for ‘Chief Ethics Officers’. “Universities are collaborative,” said Chi. Universities’ research will flourish with more collaboration at a global scale. Collaborative research shows higher citation and impact rates. Instead of competing against one another, universities and industries should collaborate for advancing research. He argued further saying, “If they can uphold this reputation, universities, not companies, will be the institutions that people trust to influence and educate the next generation. Universities, in contrast to industry, have long-term vision, can facilitate collaborative research, and are trustworthy.” (President Joseph Aoun, Northeastern University) In the last day’s keynote speech, President Joseph Aoun of Northeastern University said that higher education risks becoming obsolete if it does not fully embrace lifelong learning. He also talked about preparing learners to succeed in the AI age. He said that lifelong learners made up 74 percent of learners in the US, and only 34 percent of universities in the country fill their seats, but higher education has not yet incorporated lifelong learning as part of its core mission. He said that lifelong learning is going to require that we listen to the needs of society, of both individuals and organizations. He also called for institutions to create curricula based on what he termed ‘humanics’ – the integration of technological literacy, data literacy, and human literacy, and said that this should be combined with experiential learning. (from left: So Young Kim, Guohua Chen, Aqil Jamal, Mooyoung Jung and Max Lu) (from left: Hubo and Duncan Ross, chief data officer of THE)
2019.04.09
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KAIST-KU Joint Research Center for Smart Healthcare & Transportation
(President Shin shakes hands with KU acting Presidedent Arif Al Hammdi at the KAIST-KU Joint Research Center opening ceremony on April 8.) KAIST opened the KAIST-Khalifa University Joint Research Center with Khalifa University on April 8. The opening ceremony was held at Khalifa University and was attended by President Sung-Chul Shin and Khalifa University Acting President Arif Al Hammadi. The new research center reflects the evolution of the long-established partnership between the two institutions. The two universities have already made very close collaborations in research and education in the fields of nuclear and quantum engineering. The launch of this center expanded their fields of collaboration to smart healthcare and smart transportation, key emerging sectors in the Fourth Industrial Revolution. President Shin signed an MOU with the UAE Minister of State for Advanced Science Sarah Amiri and Khalifa University to expand mutual collaboration in technology development and fostering human capital last year. The center will conduct research and education on autonomous vehicles, infrastructure for autonomous vehicle operation, wireless charging for electric vehicles, and infrastructure for electric autonomous vehicles. As for smart healthcare, the center will focus on healthcare robotics as well as sensors and wearable devices for personal healthcare services. President Shin, who accompanied a research team from the Graduate School of Green Transportation, said, “We are very delighted to enter into this expanded collaboration with KU. This partnership justifies our long-standing collaboration in the areas of emerging technologies in the Fourth Industrial Revolution while fostering human capital.” KU Acting President Arif Al Hammadi added, “The outcome of these research projects will establish the status of both institutions as champions of the Fourth Industrial Revolution, bringing benefits to our communities. We believe the new research center will further consolidate our status as a globally active, research-intensive academic institution, developing international collaborations that benefit the community in general.”
2019.04.09
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Unravelling Inherent Electrocatalysis to Improve the Performance of Hydrogen Fuel Cells
(Figure 1. Electrode structure for the precise evaluation of the metal nanoparticles’ electrochemical catalytic characteristics at a high temperature.) A KAIST team presented an ideal electrode design to enhance the performance of high-temperature fuel cells. The new analytical platform with advanced nanoscale patterning method quantitatively revealed the electrochemical value of metal nanoparticles dispersed on the oxide electrode, thus leading to electrode design directions that can be used in a variety of eco-friendly energy technologies. The team, working under Professor WooChul Jung and Professor Sang Ouk Kim at the Department of Materials Science and Engineering, described an accurate analysis of the reactivity of oxide electrodes boosted by metal nanoparticles, where all particles participate in the reaction. They identified how the metal catalysts activate hydrogen electro-oxidation on the ceria-based electrode surface and quantify how rapidly the reaction rate increases with the proper choice of metals. Metal nanoparticles with diameters of 10 nanometers or less have become a key component in high-performance heterogeneous catalysts, primarily serving as a catalytic activator. Recent experimental and theoretical findings suggest that the optimization of the chemical nature at the metal and support interfaces is essential for performance improvement. However, the high cost associated with cell fabrication and operation as well as poorer stability of metal nanoparticles at high temperatures have been a long-standing challenge. To solve this problem, the team utilized a globally recognized metal nano patterning technology that uses block copolymer self-assembled nano templates and succeeded in uniformly synthesizing metal particles 10 nanometers in size on the surface of oxide fuel cell electrodes. They also developed a technology to accurately analyze the catalyst characteristics of single particles at high temperatures and maximize the performance of a fuel cell with minimal catalyst use. The research team confirmed that platinum, which is a commonly used metal catalyst, could boost fuel cell performance by as much as 21 times even at an amount of 300 nanograms, which only costs about 0.015 KRW. The team quantitatively identified and compared the characteristics of widely used metal catalysts other than platinum, such as palladium, gold, and cobalt, and also elucidated the precise principle of catalyst performance through theoretical analysis. (Figure 2. Comparison of the electrochemical catalytic characteristics for various 10nm metal nanoparticles (platinum, palladium, cobalt, gold) at a high temperature.) Professor Jung said, "We have broken the conventional methods of increasing the amount of catalyst which have deemed inefficient and expensive. Our results suggest a clear idea for high performance fuel cells using very small amounts of nanoparticles. This technology can be applied to many different industrial fields, advancing the commercialization of eco-friendly energy technologies such as fuel cells that generate electricity and electrolytic cells that produce hydrogen from water.” The research has been published as the cover article of Nature Nanotechnology in the March issue. This research was carried out with support from the Nano-Material Technology Development Program through the National Research Foundation of Korea.
2019.03.28
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True-meaning Wearable Displays: Self-powered, Washable and Wearable
(Video: The washing process of wearing display module) When we think about clothes, they are usually formed with textiles and have to be both wearable and washable for daily use; however, smart clothing has had a problem with its power sources and moisture permeability, which causes the devices to malfunction. This problem has now been overcome by a KAIST research team, who developed a textile-based wearable display module technology that is washable and does not require an external power source. To ease out the problem of external power sources and enhance the practicability of wearable displays, Professor Kyung Cheol Choi from the School of Electrical Engineering and his team fabricated their wearing display modules on real textiles that integrated polymer solar cells (PSCs) with organic light emitting diodes (OLEDs). PSCs have been one of the most promising candidates for a next-generation power source, especially for wearable and optoelectronic applications because they can provide stable power without an external power source, while OLEDs can be driven with milliwatts. However, the problem was that they are both very vulnerable to external moisture and oxygen. The encapsulation barrier is essential for their reliability. The conventional encapsulation barrier is sufficient for normal environments; however, it loses its characteristics in aqueous environments, such as water. It limits the commercialization of wearing displays that must operate even on rainy days or after washing. To tackle this issue, the team employed a washable encapsulation barrier that can protect the device without losing its characteristics after washing through atomic layer deposition (ALD) and spin coating. With this encapsulation technology, the team confirmed that textile-based wearing display modules including PSCs, OLEDs, and the proposed encapsulation barrier exhibited little change in characteristics even after 20 washings with 10-minute cycles. Moreover, the encapsulated device operated stably with a low curvature radius of 3mm and boasted high reliability. Finally, it exhibited no deterioration in properties over 30 days even after being subjected to both bending stress and washing. Since it uses a less stressful textile, compared to conventional wearable electronic devices that use traditional plastic substrates, this technology can accelerate the commercialization of wearing electronic devices. Importantly, this wearable electronic device in daily life can save energy through a self-powered system. Professor Choi said, “I could say that this research realized a truly washable wearable electronic module in the sense that it uses daily wearable textiles instead of the plastic used in conventional wearable electronic devices. Saving energy with PSCs, it can be self-powered, using nature-friendly solar energy, and washed. I believe that it has paved the way for a ‘true-meaning wearable display’ that can be formed on textile, beyond the attachable form of wearable technology.” This research, in collaboration with Professor Seok Ho Cho from Chonnam National University and led by Eun Gyo Jeong, was published in Energy and Environmental Science (10.1039/c8ee03271h) on January 18, 2019. Figure 1. Schematic and photo of a washable wearing display module Figure 2. Cover page of Energy and Environmental Science
2019.03.21
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