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KAIST Finds the Principle of Electric Wind in Plasma
(From left: Professor Wonho Choe and PhD Sanghoo Park)
A KAIST team identified the basic principle of electric wind in plasma. This finding will contribute to developing technology in various applications of plasma, including fluid control technology.
Professor Wonho Choe from the Department of Physics and his team identified the main principle of neutral gas flow in plasma, known as ‘electric wind’, in collaboration with Professor Se Youn Moon’s team at Chonbuk National University.
Electric wind in plasma is a well-known consequence of interactions arising from collisions between charged particles (electrons or ions) and neutral particles. It refers to the flow of neutral gas that occurs when charged particles accelerate and collide with a neutral gas.
This is a way to create air movement without mechanical movement, such as fan wings, and it is gaining interest as a next-generation technology to replace existing fans. However, there was no experimental evidence of the cause.
To identify the cause, the team used atmospheric pressure plasma. As a result, the team succeeded in identifying streamer propagation and space charge drift from electrohydrodynamic (EHD) force in a qualitative manner.
According to the team, streamer propagation has very little effect on electric wind, but space charge drift that follows streamer propagation and collapse was the main cause of electric wind.
The team also identified that electrons, instead of negatively charged ions, were key components of electric wind generation in certain plasmas.
Furthermore, electric wind with the highest speed of 4 m/s was created in a helium jet plasma, which is one fourth the speed of a typhoon. These results indicate that the study could provide basic principles to effectively control the speed of electric wind.
Professor Choe said, “These findings set a significant foundation to understand the interactions between electrons or ions and neutral particles that occur in weakly ionized plasmas, such as atmospheric pressure plasmas. This can play an important role in expanding the field of fluid-control applications using plasmas which becomes economically and commercially interest.”
This research, led by PhD Sanghoo Park, was published online in Nature Communications on January 25.
Figure 1. Plasma jet image
Figure 2. The differences in electric wind speeds and voltage pulse
2018.03.02 View 6955 -
Successful Synthesis of Gamma-Lanctam Rings from Hydrocarbons
(The team of Professor Chang, far right, at the Department of Chemistry)
KAIST chemists have designed a novel strategy to synthesize ring-shaped cyclic molecules, highly sought-after by pharmaceutical and chemical industries, and known as gamma-lactams. This study describes how these five-membered rings can be prepared from inexpensive and readily available feedstock hydrocarbons, as well as from complex organic molecules, such as amino acids and steroids.
Gamma-lactams find several applications in medicinal, synthetic, and material chemistry. For example, they are included in a large number of pharmaceutically active compounds with antibiotic, anti-inflammatory, and anti-tumoral functions. This research was published in Science on March 2.
Conversion of hydrocarbons into nitrogen-containing compounds is an important area of research, where the challenge lies in breaking strong carbon-hydrogen (C−H) bonds, and converting them into carbon-nitrogen (C–N) bonds in a controlled fashion. For this reason, hydrocarbons are difficult to use as starting materials, albeit the fact that they exist in large quantities in nature.
Over the last 35 years, chemists have found ways of converting simple hydrocarbons into nitrogen-containing rings, such as indoles or pyrrolidines, but gamma-lactams proved impossible to prepare using the same approaches. Researchers hypothesized that such failure was due to alternative chemical pathways that steer the reaction away from the wanted rings: The reaction intermediate (carbonylnitrene) quickly breaks down into unsought products. Using computer models of the desired and undesired reaction pathways, the team found a strategy to completely shut down the latter in order to obtain the longed-for gamma-lactams. For the first time, these four carbons and one nitrogen cyclic molecules were obtained directly from simple feedstock chemicals.
Led by Professor Chang Sukbok at the Department of Chemistry, the team designed the winning reaction with the help of computer simulations that analyze the reaction mechanisms and calculate the energy required for the reaction to take place. According to such computer predictions, the reaction could follow three pathways, leading to the formation of either the desired gamma-lactam, an unwanted product (isocyanate), or the degradation of the catalyst caused by the substrate reacting with the catalyst backbone. Combining experimental observations and detailed computer simulations, the team designed an iridium-based catalyst, highly selective for the gamma-lactam formation. In this way, the two undesired pathways were systematically shut down, leaving the formation of the nitrogen-containing ring as the only possible outcome. Professor Chang is also in charge of the Center for Catalytic Hydrocarbon Functionalizations at the Institute for Basic Science (IBS).
“With this work we offer a brand new solution to a long-standing challenge and demonstrate the power of what we call mechanism-based reaction development,” explains Professor Baik Mu-Hyun, a corresponding author of the study.
Beyond using cheap feedstock hydrocarbons as substrates, the team was also successful in converting amino acids, steroids, and other bio-relevant molecules into gamma-lactams, which might find a variety of applications as plant insecticide, drugs against parasitic worms, or anti-aging agents. This new synthetic technology gives much easier access to these complicated molecules and will enable the development of potential drugs in a much shorter amount of time at a lower cost.
Figure 1: Selective amidation reaction using newly designed iridium (Ir) catalysts. Abundant in nature Hydrocarbons are used as substrates to synthesize nitrogen-containing ring, called gamma-lactams.
Figure 2: Three possible reaction pathways and energy barriers predicted by computational chemistry. The scientists developed new iridium-based catalysts that are highly selective for the C–H insertion pathway which leads to the desired gamma-lactam molecules.
Figure 3: Interesting gamma-lactams derived from natural and unnatural amino acids, steroids, etc., which may be used to protect plants against insects, fight parasitic worms, or as anti-aging agents.
2018.03.02 View 7786 -
Aqueous Storage Device Needs Only 20 Seconds to Go
(from left: PhD candidate Il Woo Ock and Professor Jeung Ku Kang)
A KAIST research team developed a new hybrid energy storage device that can be charged in less than half a minute. It employs aqueous electrolytes instead of flammable organic solvents, so it is both environmentally friendly and safe. It also facilitates a boosting charge with high energy density, which makes it suitable for portable electronic devices.
Professor Jeung Ku Kang and his team from the Graduate School of Energy, Environment, Water, and Sustainability developed this hybrid energy storage with high energy and power densities along over a long cycle life by assembling fibre-like polymer chain anodes and sub-nanoscale metal oxide cathodes on graphene.
Conventional aqueous electrolyte-based energy storage devices have a limitation for boosting charges and high energy density due to low driving voltage and a shortage of anode materials.
Energy storage device capacity is determined by the two electrodes, and the balance between cathode and anode leads to high stability. In general, two electrodes show differences in electrical properties and differ in ion storage mechanism processes, resulting in poor storage and stability from the imbalance.
The research team came up with new structures and materials to facilitate rapid speed in energy exchange on the surfaces of the electrodes and minimize the energy loss between the two electrodes.
The team made anodes with graphene-based polymer chain materials. The web-like structure of graphene leads to a high surface area, thereby allowing higher capacitance.
For cathode materials, the team used metal oxide in sub-nanoscale structures to elevate atom-by-ion redox reactions. This method realized higher energy density and faster energy exchange while minimizing energy loss.
The developed device can be charged within 20 to 30 seconds using a low-power charging system, such as a USB switching charger or a flexible photovoltaic cell. The developed aqueous hybrid energy device shows more than 100-fold higher power density compared to conventional aqueous batteries and can be rapidly recharged. Further, the device showed high stability with its capacity maintained at 100% at a high charge/discharge current.
Professor Kang said, “This eco-friendly technology can be easily manufactured and is highly applicable. In particular, its high capacity and high stability, compared to existing technologies, could contribute to the commercialization of aqueous capacitors. The device can be rapidly charged using a low-power charging system, and thus can be applied to portable electronic device.”
This research, led by a PhD candidate Il Woo Ock, was published in Advanced Energy Materials on January 15.
Figure 1. Switching wearable LED kit with two AHCs in series charged by a flexible photovoltaic cell
Figure 2. Schematic diagram for aqueous hybrid capacitors
Figure 3. TEM images of anode and cathode
2018.02.28 View 12173 -
Samsung Electronics' Chairman Kwon Becomes the First Alumnus Honorary Doctorate
(Samsung Electronics' Chairman & CEO Kwon,left, and President Shin)
The semiconductor has bred innovation in Korea, as one of the staples of economic growth. Without the success of the semiconductor industry of Korea, it is hard to imagine the high tech dominance in the global market enjoyed by Korean companies.
It is said that one in every four Ph.D.s working in the semiconductor industry of Korea graduated from KAIST. Among them, Chairman and CEO Oh-Hyun Kwon of Samsung Electronics, Class of 1977, has arrived at the epitome of this top industry.
KAIST’s class of 1977 produced many movers and shakers in Korea’s innovation efforts. Now in their mid-60s, they were the players who embodied Korea’s ICT and helped it become a global powerhouse. They are the ones who worked for and witnessed the socio-economic transformation of Korea through innovation.
In recognition of his unsurpassable entrepreneurship, which made the remarkable strides in the semiconductor and electronics industry in Korea and beyond, Chairman Kwon was honored as the first recipient of an honorary doctorate from his alma mater on February 23 during the 2018 commencement ceremony.
After completing his Master's in Electrical Engineering at KAIST in 1977, he earned his Ph.D. in Electrical Engineering from Stanford University. The first honorary degree bestowed to an alumnus was conferred by the first alumnus President of KAIST Sung-Chul Shin. President Shin said that Chairman Kwon’s exceptional leadership has inspired the KAIST community and exemplified the spirit of KAIST.
Currently serving as chairman & CEO of Samsung Electronics and Samsung Advanced Institute of Technology (SAIT), Kwon has worked for Samsung in a variety of key positions in their semiconductor division since 1985.
In the mid-1980s, Japan was leading the global semiconductor market. At Samsung, Chairman Kwon, who was in charge of the memory semiconductor team, successfully developed 4M DRAM. Later in 1992, he played a leading role in the development of the world’s first 64M DRAM.
The success of 4M DRAM and 64M DRAM led Samsung to clinch the top position in the DRAM and NAND flash business around the world. This helped Samsung emerge as a global leader in the semiconductor industry.
As a result, Samsung, as well as the national economy, could gain significant momentum to build national competitiveness and economic growth. The outstanding technological leadership of Chairman Kwon led to the development of proprietary semiconductor design and processes technologies as well as numerous patents.
He also played a leadership role in creating a mutual growth environment among conglomerates rather than merely engaging in direct competition. Chairman Kwon made every effort to establish the cornerstone of mutual growth, especially in relationships with small and medium-sized enterprises (SMEs). His win-win collaboration initiatives among conglomerates and SMEs made a significant impact on the development of the entire industry of Korea.
In his acceptance speech, he charged the graduates to embrace challenges, to collaborate with peers, and create their own future.
The full text of his speech is printed below.
Graduates and distinguished guests! I extend my sincere congratulations to my fellow graduates, as you are awarded degrees for your deep efforts, as well as to the parents and family members who have supported you.
In 1977, I received my Master’s degree in Electrical Engineering from KAIST. Today, as the first honorary doctor among KAIST graduates, I am truly honored to be here. I am deeply grateful to all of you, including President Sung-Chul Shin and the Chairman of the Board of Trustees, Jang-Moo Lee.
Today, I want to tell you about the experiences and lessons I have learned from my 40 years of corporate management experience.
First, you should lead and drive changes by yourself. In the process of realizing a dream, the situation and circumstances do not always proceed as you planned.
I started my career as a researcher. However, I had to continuously transform myself into a project leader, business team leader, and CEO. It was challenging every time, due to a lack of preparing and my insufficient ability. However, I have always accomplished the intended goal through the mindset of embracing changes and studying new things.
It is said that the survivors are not always the strongest nor the most intelligent, but the ones who are the most adaptive to changes. We can only be the last survivor if we have the character to see those small signs that signal changes are coming and cope with changes well. Take changes positively and actively and then, transform yourself to match a given situation.
In addition, it is important to understand others. When it comes to one’s career, there is nothing that you can do alone without the assistance of others. If it is not possible to do everything by yourself, you will need to supplement your efforts through the help of others. To do this, you need to understand your colleagues, bosses, and customers first.
People, who work in tech tend to cage themselves in their own silos. But in an era of destructive innovation, where boundaries of industries and technologies are collapsing at a breakneck pace, scientists also need to enhance their understanding of various areas such as culture, art, and the humanities.
This is a famous verse from a poem by Chun-Soo Kim.
Before I called his name,
He was nothing but a gesture.
When I called his name, He came to me and became a flower.
Make wonderful synergy by making your partner a flower and complementing each other. When you first notice the true value of another person and interact with them, the value of the individual will be doubled and will bring about a greater impact.
Finally, we all need to cooperate with each other. All of you here, including myself, are people who have benefited from society. We must cooperate with each other and give back to society for the best results.
A biologist once said that incremental evolution comes from competition, but fundamental evolution comes from cooperation. Great leaders should achieve results through cooperation rather than competition.
You are the future leaders with top-class knowledge. I hope you will become great leaders who have wisdom that combines external resources with your abilities.
Now, graduates of 2018 who are standing at the starting line, we often worry about an unpredictable tomorrow. However, the smartest way to predict the future is to create the future for ourselves. Moreover, we can try again even though we sometimes make mistakes. I urge you to make future you are hoping for.
Once again, I would like to thank you for this honorary doctorate and extend my sincere wishes for the endless development of KAIST and the best of luck to the futures of these graduates. Thank you.
2018.02.26 View 7032 -
The 2018 Commencement of KAIST at a Glance
KAIST awarded a total of 2, 736 degrees at the 2018 commencement ceremony on February 23. Among the honorees, Chairman and CEO of Samsung Electronics and Samsung Advanced Institute of Technology (SAIT) Oh-Hyun Kwon was recognized as the first alumnus honorary doctorate recipient of KAIST.
More than 5,000 family, friends, and graduates including distinguished guests of Minister of Science and ICT Young-Min Yu, the Member of National Assembly Kyung-Jin Kim, Chairman of the KAIST Board of Trustees Jang-Moo Lee, and the Chairperson of the KAIST Development Foundation Soo-Young Lee attended to celebrate the graduates. During the commencement, a total of 2,736 students earned degrees: 644 PhD degrees, 1,352 master’s degrees, and 740 bachelor’s degrees.
(Minister of Science and ICT Young-Min Yu)
(The Member of National Assembly Kyung-Jin Kim)
This year, Chairman and CEO of Samsung Electronics and SAIT Kwon shared the spotlight with many other graduates. Kwon received his Master’s degree in Electrical Engineering from KAIST in 1977 and completed his Ph.D. in Electrical Engineering from Stanford University in 1985. During his more than 33-year career at Samsung, he has made significant contribution to the development of 4M DRAM and the world’s first 64M DRAM. The success of 4M DRAM and 64 DRAM led Samsung to clinch the top position in the DRAM and NAND flash business around the world. This helped Samsung emerge as a global leader in the semiconductor industry.
(From left: Chairman and CEO of Samsung Electronics and SAIT Oh-Hyun Kwon and KAIST President Sung-Chul Shin)
During the commencement speech, Kwon and President Shin both highlighted the importance of collaboration instead of competition.
Kwon encouraged the graduates to understand others to make wonderful synergy. “When you first notice the true value of another person and interact with them, the value of the individual will be doubled and will bring about a greater impact,” he said.
Also, he stressed having a collaborative mindset by saying, “All of you here, including myself, are people who have benefited from society. We must cooperate with each other and give back to society for the vest results.”
While highlighting the core values of KAIST, creativity, challenge and caring, President Shin also emphasized collaboration with others. He said, “In the future, expertise in a single discipline will not lead to new inventions or discoveries. This highlights the importance of multidisciplinary, convergence research. The key to success lies in the acknowledgement of your peers as partners for mutual growth. Your partners will make up your weak areas and become your most important asset. May you expand your personal network by finding valuable partners not only within your laboratory and workplace, but beyond Korea.”
“Go out into the world and change it as a global shaper, global innovator, and global mover. I hope that each and every one of you will add benefits the world and your legacy will be remembered for generations to come. This is your obligation as a graduate of KAIST,” he said.
Click here to view the full text of President Sung-Chul Shin’s address to the graduates
+ List of academically outstanding undergraduate degree recipients who received honors during the Commencement 2018 of KAIST
Award
Department
Winner
Minister of Science and ICT Award
Dept. of Mathematical Sciences
Seong-Hyeok Park
KAIST Board Chairperson Award
School of Computing
Hyeong-Seok Kim
KAIST President Award
Dept. of Chemistry
Hoi-Min Cheong
KAIST Development Foundation Chairperson Award
Dept. of Biological Sciences
Gi-Song Kim
Dept. of Industrial & Systems Engineering
Seung-Hun Lee
2018.02.23 View 9843 -
Soul-Searching & Odds-Defying Determination: A Commencement Story of Dr. Tae-Hyun Oh
(Dr. Tae-Hyun Oh, one of the 2736 graduates of the 2018)
Each and every one of the 2,736 graduates has come a long way to the 2018 Commencement. Tae-Hyun Oh, who just started his new research career at MIT after completing his Ph.D. at KAIST, is no exception.
Unlike the most KAIST freshmen straight out of the ingenious science academies of Korea, he is among the many who endured very challenging and turbulent adolescent years. Buffeted by family instability and struggling during his time at school, he saw himself trapped by seemingly impenetrable barriers. His mother, who hated to see his struggling, advised him to take a break to reflect on who he is and what he wanted to do.
After dropping out of high school in his first year, ways to make money and support his family occupied his thoughts. He took on odd jobs from a car body shop to a gas station, but the real world was very tough and sometimes even cruel to the high school dropout.
Bias and prejudice stigmatizing dropouts hurt him so much. He often overheard a parent who dropped by the body shop that he worked in saying, “If you do not study hard, you will end up like this guy.” Hearing such things terrified him and awoke his sense of purpose. So he decided to do something meaningful and be a better man than he was.
“I didn’t like the person I was growing up to become. I needed to find myself and get away from the place I was growing up. It was my adventure and it was the best decision I ever made,” says Oh.
After completing his high school diploma national certificate, he planned to apply to an engineering college. On his second try, he gained admission into the Department of Electrical Engineering at Kwang Woon University with a full scholarship. He was so thrilled for this opportunity and hoped he could do well at college. Signal processing and image processing became the interest of his research and he finished his undergraduate degree summa cum laude.
Gaining confidence in his studies, he searched around graduate school department websites in Korea to select the path he was interested in. Among others, the Robotics and Computer Vision Lab of Professor In-So Kweon at the Department of Electrical Engineering at KAIST was attractive to him.
Professor Kweon’s lab is globally renowned for robot vision technology. Their technologies were applied into HUBO, the KAIST-developed bimodal humanoid robot that won the 2015 DARPA Challenges.
“I am so appreciate of Professor Kweon, who accepted and guided me,” he said. Under Professor Kweon’s advising, he could finish his Master’s and Ph.D. courses in seven years. The mathematical modeling on fundamental computer algorithms became his main research topic.
While at KAIST, his academic research has blossomed. He won a total of 13 research prizes sponsored by corporations at home and abroad such as Kolon, Samsung, Hyundai Motors, and Qualcomm.
In 2015, he won the Microsoft Research Asia Fellowship as the sole Korean among 13 Ph.D. candidates in the Asian region. With the MSRA fellowship, he could intern at the MS Research Beijing Office for half a year and then in Redmond, Washington in the US.
“Professor Kweon’s lab filled me up with knowledge. Whenever I presented our team’s paper at an international conference, I was amazed by the strong interest shown by foreign experts, researchers, and professors. Their strong support and interest encouraged me a lot. I was fully charged with the belief that I could go abroad and explore more opportunities,” he said.
Dr. Oh, who completed his dissertation last fall, now works at the Department of Electrical Engineering and Computer Science at MIT under Professor Wojciech Matusik.
“I think the research environment at KAIST is on par with MIT. I have very rich resources for my studies and research at both schools, but at MIT the working culture is a little different and it remains a big challenge for me. I am still not familiar with collaborative work with colleagues from very diverse backgrounds and countries, and to persuade them and communicate with them is very tough. But I think I am getting better and better,” he said.
Oh, who is an avid computer game player as well, said life seems to be a game. The level of the game will be upgraded to the next level after something is accomplished. He feels great joy when he is moving up and he believes such diverse experiences have helped him become a better person day by day. Once he identified what gave him a strong sense of purpose, he wasn’t stressed out by his studies any more. He was so excited to be able to follow his passion and is ready for the next challenge.
2018.02.23 View 9107 -
KAIST, First to Win the Cube Satellite Competition
Professor Hyochoong Bang from the Department of Aerospace Engineering and his team received the Minister of Science and ICT Award at the 1st Cube Satellite Competition.
The team actually participated in the competition in 2012, but it took several years for the awarding ceremony since it took years for the satellites to be designed, produced, and launched.
The KAIST team successfully developed a cube satellite, named ‘Little Intelligent Nanosatellite of KAIST (LINK)’ and completed its launch in April 2017.
LINK (size: 20cmx10cmx10cm, weight: 2kg) mounted mass spectrometry and Langmuir probe for Earth observation. The Langmuir probe was developed by Professor Kyoung Wook Min from the Department of Physics, KAIST.
Yeerang Lim, a PhD student from the Department of Aerospace Engineering said, “I still remember the feeling that I had on the day when LINK launched into orbit and sent back signals. I hope that space exploration is not something far away but attainable for us in near future.”
2018.02.22 View 9347 -
Low-power, Flexible Memristor Circuit for Mobile and Wearable Devices
(from left: Yunyong Nam, Professor Sung-Yool Choi and Byung Chul Jang)
A KAIST research team succeeded in developing an energy efficient, nonvolatile logic-in-memory circuit by using a memristor. This novel technology can be used as an energy efficient computing architecture for battery-powered flexible electronic systems, such as mobile and wearable devices.
Professor Sung-Yool Choi from the School of Electrical Engineering and Professor Sang-Hee Ko Park from the Department of Materials Science and Engineering developed a memristive nonvolatile logic-in-memory circuit.
Transistor-based conventional electronic systems have issues with battery supply and a long standby period due to their volatile computing architecture. The standby power consumption caused by subthreshold leakage current limits their potential applications for mobile electronic devices. Also, their physical separation of memory and processor causes power consumption and time delay during data transfer.
In order to solve this problem, the team developed a logic-in-memory circuit that enables data storage as well as logic operation simultaneously. It can minimize energy consumption and time delay because it does not require data transfer between memory and processor.
The team employed nonvolatile, polymer-based memristors and flexible back-to-back Schottky diode selector devices on plastic substrates. Unlike the conventional architecture, this memristive nonvolatile logic-in-memory is a novel computing architecture that consumes a minimal amount of standby power. This one-selector-one memristor (1S-1M) solved the issue of undesirable leakage currents, known as ‘sneak currents’.
They also implemented single-instruction multiple-data (SIMD) to calculate multiple values at once.
The proposed parallel computing method using a memristive nonvolatile logic-in-memory circuit can provide a low-power circuit platform for battery-powered flexible electronic systems with a variety of potential applications.
Professor Choi said, “Flexible logic-in-memory circuits integrating memristor and selector device can provide flexibility, low power, memory with logic functions. This will be a core technology that will bring innovation to mobile and wearable electronic systems.”
This research, collaborated with Ph.D. candidates Byung Chul Jang and Yunyong Nam, was published and chosen as the cover of Advanced Functional Materials on January 10.
Figure 1. Cover of the Advanced Functional Materials
Figure 2. Schematic illustration and cross-sectional TEM image of flexible memristive nonvolatile logic-in-memory circuit
Figure 3. Test performance
Figure 4. Parallel logic operation within 1S-1M memristor array
2018.02.21 View 6344 -
KAIST to Develop Technology to Control Topological Defects
(Professor Chan-Ho Yang and PhD candidate Kwang-Eun Kim)
Professor Chan-Ho Yang and his team from the Department of Physics developed technology to create and remove topological defects in ferroelectric nanostructures.
This technology will contribute to developing topological defect-based storage that will allow the saving of massive amounts of information in a stable manner.
Topology refers to the property of matter upon deformation, in which a circle and a triangle are considered to be the same topologically.
During the announcement of the 2016 Nobel Prize in Physics, the concept of topology was explained with a bagel with a hole, cinnamon bread without a hole, and a glass cup. Although the cinnamon bread and the glass cup have different appearances, they are topologically the same since neither has a hole. In the same sense, the bagel and the cinnamon bread are topologically different.
In other words, topology of matter is conserved and its properties cannot be altered by continuous deformation.
Using this topological texture can produce information storage devices that can protect the stored information from external stimuli, but the data can still be written and erased, resulting in ideal non-volatile memory.
Unlike ferroelectrics, magnetic topological defect structures such as the ferromagnetic vortex and skyrmion have already been implemented.
Ferroelectrics, which have aligned electric dipoles without external electric fields, can stabilize topological defect structures to a smaller size using less energy; however, further research on ferroelectrics has not been carried out sufficiently. This is due to a lack of research on stabilizing topological defect structures and how to control them in an experimental setting.
To overcome this problem, the team applied inhomogeneous deformations to ferroelectric nanostructures to successfully stabilize the topological defect structures. The team manufactured a ferroelectric nanoplate structure on a special board, which can exert strong compression from the bottom surface while the sides and the upper surfaces of the structure is free from deformation.
This structure led to radial compressive strain relaxation, in which deformations of the lattice stabilize the vortex structure of ferroelectrics.
This could lead to the establishment of the core principle of topological ferroelectric memory of high density, high efficiency, and high stability.
Professor Yang said, “Ferroelectrics are nonconductor but topological ferroelectric quasiparticles could carry electrical conductivity locally. This finding could be expanded to new quantum device research.”
This research, led by the PhD candidate Kwang-Eun Kim, was published in Nature Communications on January 26.
The study was co-conducted by Professor Si-Young Choi and Dr. Tae Yeong Koo from POSTECH, Professor Long-Qing Chen from The Pennsylvania State University, and Professor Ramamoorthy Ramesh from the University of California at Berkeley.
Figure 1. Five different topological structures produced by controlling the number of topological defects
2018.02.19 View 7237 -
Professor Il-Doo Kim Recevies the Song-gok Award
Professor Il-Doo Kim from the Department of Materials Science and Engineering at KAIST received the 20th Song-gok Science and Technology Award from Korea Institute of Science and Technology (KSIT).
The Song-gok Science and Technology Award was established to praise the accomplishments of the first president, Hyung-seop Choi, whose penname is Song-gok. The award selects a recipient in the field of materials and technology every other year.
Professor Kim, in recognition of his outstanding research and contributions to materials science in Korea, received the award during the 52nd anniversary ceremony of KIST on February 9.
Professor Kim focuses on developing nanofiber gas sensors for diagnosing disease in advance by analyzing exhaled biomarkers with electrospinning technology.
He has published more than 211 papers and has recorded more than 9,650 citations and 50 h-index.
Professor Kim has registered 107 patents and applied 38 patents in Korea while registering 29 patents and applying 16 patents overseas. Also, he transferred four technologies in 2017.
Professor Kim is recognized as one of the researchers who is leading nanofiber technology. On January 17, he made a keynote speech at the 5th International Conference on Electrospinning, which was his fourth keynote speech at that conference.
Moreover, he received the Technology Innovation Award at the College of Engineering, KAIST on December 19, 2017.
Professor Kim said, “It is my great honor to receive the Song-gok Science and Technology Award. I would like to bring distinction to KAIST by taking the lead in the commercializing a nanofiber-based highly sensitive nanosensors, diversifying and commercializing technology using nanofiber.”
2018.02.13 View 7322 -
First Female Grand Prize Awardee of Samsung Humantech
Yeunhee Huh, PhD candidate (Professor Gyu-Hyeong Cho) from the School of Electrical Engineering received the grand prize of the 24th Humantech Paper Award. She is the first female recipient of this prize since its establishment in 1994. The Humantech Paper Award is hosted by Samsung Electronics and sponsored by the Ministry of Science and ICT with JoongAng Daily Newspaper. Her paper is titled, ‘A Hybrid Structure Dual-Path Step-Down Converter with 96.2％ Peak Efficiency using 250mΩ Large-DCR Inductor’. Electronic devices require numerous chips and have a power converter to supply energy adequately. She proposed a new structure to enhance energy efficiency by combining inductors and capacitors. Enhancing energy efficiency can reduce energy loss, which prolongs battery hours and solves overheating of devices; for instance, energy loss leads to the overheating issue affecting phone chargers. This technology can be applied to various electronic devices, such as cell phones, laptops, and drones. Huh said, “Power has to go up in order to meet customers’ needs; however the overheating problem emerges during this process. This problem affects surrounding circuits and causes other issues, such as malfunctions of electronic devices. This technology may vary according to the conditions, but it can enhance energy efficiency up to 4%.”During the ceremony, about eight hundred million KRW worth cash prizes was conferred to 119 papers. KAIST (44 papers) and Gyeonggi Science High School (6 papers) received special awards given to the schools.
2018.02.12 View 7618 -
Professor Hojong Chang Wins the Best Paper Award at ISIITA 2018
Professor Hojong Chang from the KAIST Institute won the best paper award at the International Symposium on Innovation in Information Technology and Application (ISIITA) 2018.
ISIITA is a global networking symposium in which leading researchers in the field of information technology and applications gather to exchange knowledge on technological convergence.
Professor Chang won the prize for his paper, titled ‘A Study on the Measurement of Aptamer in Urine Using SiPM’.
This paper proposes using aptamer to measure and analyze the density of sodium and potassium contained in urine, allowing diseases to be diagnosed in advance.
Professor Chang said, “With a point-of-care test system that facilitates a quick diagnosis without extra processes, such as centrifugation, it is possible to get an early diagnosis and check infection in real time. Through generalizing this crucial technology, we expect to develop adequate technology for enhancing quality of life.
2018.02.12 View 6509