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KAIST Develops Core Technology to Synthesize a Helical Nanostructure
Professor Dong-Ki Yoon’s research team of the Graduate School of Nanoscience and Technology (GSNT) at KAIST has developed helical nanostructures using self-assembly processes. The results were published in the Proceedings of the National Academy of Sciences of the United States of America(PNAS) on the October 7th. This technology enables the synthesis of various helical structures on a relatively large confined area. Its synthesis is often considered the most arduous for three dimensional structures. Formed from liquid crystal, the structure holds a regular helical structure within the confined space of 20 to 300 nanometers. Also, the distance between each pattern increased as the diameter of the nanostructure increased. Liquid crystals have a unique property of responding sensitively to the surrounding electromagnetic field. The technology, in combination with the electromagnetic property of liquid crystal, is expected to foster the development of highly efficient optoelectronic devices. Using this technology, it is possible to develop three dimensional patterning technology beyond the current semiconductor manufacturing technology which uses two dimensional photolithography processes. Three-dimensional semiconductor devices are expected to store hundred times more data than current devices. They will also lower costs by simplifying manufacturing processes. The essence of this research, “self-assembly in confined space,” refers to controlling complex nanostructures, which can be synthesized from materials such as macromolecules, liquid crystal molecules, and biomolecules in relation to surrounding environments including the temperature, concentration, and pH. The research team produced a confined space with a length of tens of nanometers by using a porous anodized aluminum membrane induced from an electrochemical reaction. They successfully synthesized independently controlled helical nanostructures by forming the helical structures from liquid crystal molecules within that space. Professor Yoon said, “This research examines the physicochemical principle of controlling helical nanostructures.” He highlighted the significance of the research and commented, “The technology enables the control of complex nanostructures from organic molecules by using confined space and surface reforming.” He added that, “When grafted with nanotechnology or information technology, this technology will spur new growth to liquid crystal-related industries such as the LCD.” The research was led by two Ph.D. candidates, Hanim Kim and Sunhee Lee, under the guidance of Professor Yoon. Dr. Tae-Joo Shin of the Pohang Accelerator Laboratory, Professor Sang-Bok Lee of the University of Maryland, and Professor Noel Clark of the University of Colorado also participated. Picture 1. Electron Microscopy Pictures and Conceptual Diagrams of Helical Nanostructures Picture 2. Electron Microscopy Pictures of Manufactured Helical Nanostructures
2014.10.29
View 7252
Extracting Light from Graphite: Core Technology of Graphene Quantum Dots Display Developed
Professor Seokwoo Jeon of the Department of Materials Science and Engineering, Professor Yong-Hoon Cho of the Department of Physics, and Professor Seunghyup Yoo of the Department of Electrical Engineering announced that they were able to develop topnotch graphene quantum dots from graphite. Using the method of synthesizing graphite intercalation compound from graphite with salt and water, the research team developed graphene quantum dots in an ecofriendly way. The quantum dots have a diameter of 5 nanometers with their sizes equal and yield high quantum efficiency. Unlike conventional quantum dots, they are not comprised of toxic materials such as lead or cadmium. As the quantum dots can be developed from materials which can be easily found in the nature, researchers look forward to putting these into mass production at low cost. The research team also discovered a luminescence mechanism of graphene quantum dots and confirmed the possibility of commercial use by developing quantum dot light-emitting diodes with brightness of 1,000 cd/m2, which is greater than that of cellphone displays. Professor Seokwoo Jeon said, “Although quantum dot LEDs have a lower luminous efficiency than existing ones, their luminescent property can be further improved” and emphasized that “using quantum dot displays will allow us to develop not only paper-thin displays but also flexible ones.” Sponsored by Graphene Research Center in KAIST Institute for NanoCentury, the research finding was published online in the April 20th issue of Advanced Optical Materials. Picture 1: Graphene quantum dots and their synthesis Picture 2: Luminescence mechanism of graphene quantum dots Picture 3: Structure of graphene quantum dots LED and its emission
2014.09.06
View 13749
Clear Display Technology Under Sunlight Developed
The late Professor Seung-Man Yang The last paper of the late Professor Seung-Man Yang, who was a past master of colloids and fluid mechanics Practical patterning technology of the next generation optical materials, photonic crystals The mineral opal does not possess any pigments, but it appears colorful to our eyes. This is because only a particular wavelength is reflected due to the regular nano-structure of its surface. The material that causes selective reflection of the light is called photonic crystals. The deceased Professor Seung-Man Yang and his research team from KAIST’s Chemical and Biomolecular Engineering Department ha ve developed micro-pattern technology using photolithographic process. This can accelerate the commercialization of photonic crystals, which is hailed as the next generation optics material. The research results were published in the April 16th edition of Advanced Materials, known as the most prestigious world-renowned journal in the field of materials science. The newly developed photonic crystal micro-pattern could be used as a core material for the next generation reflective display that is clearly visible even under sunlight. Since it does not require a separate light source, a single charge is enough to last for several days. Until now, many scientists have endeavored to make photonic crystals artificially, however, most were produced in a lump and therefore lacked efficiency. Also, the low mechanical stability of the formed structure prevented from commercialization. In order to solve these problems, the research team has copied the nano-structure of opals. Glass beads were arranged in the same nano-structure as the opal on top of the photoresist material undergoing photocuring by ultraviolet light. The glass beads were installed in the photoresist materials, and UV light was selectively exposed on micro regions. The remaining region was developed by photolithographic process to successfully produce photonic crystals in micro-patterns. The co-author of the research, KAIST Chemical and Biomolecular Engineering Department’s Professor Sin-Hyeon Kim, said, “Combining the semiconductor process technology with photonic crystal pattern technology can secure the practical applications for photonic crystals.”He also predicted “This technology can be used as the key optical material that configures the next generation reflective color display device with very low power consumption.” The late Professor Seung-Man Yang was a world-renowned expert in the field of colloids and fluid mechanics. Professor Yang published over 193 papers in international journals and continued his research until his passing in last September. He received Du Pont Science and Technology Award in 2007, KAIST Person of the Year 2008, Gyeong-Am Academy Award in 2009, as well as the President’s Award of the Republic of Korea in March 2014. The researchers devoted the achievement of this year’s research to Professor Yang in his honor. Research was conducted by KAIST Photonic-fluidic Integrated Devices Research Team, as a part of the Creative Research Program funded by the Ministry of Science, ICT and Future Planning, Republic of Korea. Figure 1. Opal [left] and the nano glass bead arrangement structure within the opal [right] Figure 2. Process chart of the photonic crystal micro-pattern formation based on photolithography Figure 3. Opal structure [left] and inverted structure of the opal [right] Figure 4. Photonic crystal micro-pattern in solid colors Figure 5. Photonic crystal micro-pattern that reflects two different crystals (Red, Green) [left] and pixelated pattern of photonic crystal in three primary colors (Red, Green, Blue) [right] that is applicable to reflective displays
2014.05.14
View 9690
Ultra-High Strength Metamaterial Developed Using Graphene
New metamaterial has been developed, exhibiting hundreds of times greater strength than pure metals. Professor Seung Min, Han and Yoo Sung, Jeong (Graduate School of Energy, Environment, Water, and Sustainability (EEWS)) and Professor Seok Woo, Jeon (Department of Material Science and Engineering) have developed a composite nanomaterial. The nanomaterial consists of graphene inserted in copper and nickel and exhibits strengths 500 times and 180 times, respectively, greater than that of pure metals. The result of the research was published on the July 2nd online edition in Nature Communications journal. Graphene displays strengths 200 times greater than that of steel, is stretchable, and is flexible. The U.S. Army Armaments Research, Development and Engineering Center developed a graphene-metal nanomaterial but failed to drastically improve the strength of the material. To maximize the strength increased by the addition of graphene, the KAIST research team created a layered structure of metal and graphene. Using CVD (Chemical Vapor Deposition), the team grew a single layer of graphene on a metal deposited substrate and then deposited another metal layer. They repeated this process to produce a metal-graphene multilayer composite material, utilizing a single layer of graphene. Micro-compression tests within Transmission Electronic Microscope and Molecular Dynamics simulations effectively showed the strength enhancing effect and the dislocation movement in grain boundaries of graphene on an atomic level. The mechanical characteristics of the graphene layer within the metal-graphene composite material successfully blocked the dislocations and cracks from external damage from traveling inwards. Therefore the composite material displayed strength beyond conventional metal-metal multilayer materials. The copper-graphene multilayer material with an interplanar distance of 70nm exhibited 500 times greater (1.5GPa) strength than pure copper. Nickel-graphene multilayer material with an interplanar distance of 100nm showed 180 times greater (4.0GPa) strength than pure nickel. It was found that there is a clear relationship between the interplanar distance and the strength of the multilayer material. A smaller interplanar distance made the dislocation movement more difficult and therefore increased the strength of the material. Professor Han, who led the research, commented, “the result is astounding as 0.00004% in weight of graphene increased the strength of the materials by hundreds of times” and “improvements based on this success, especially mass production with roll-to-roll process or metal sintering process in the production of ultra-high strength, lightweight parts for automobile and spacecraft, may become possible.” In addition, Professor Han mentioned that “the new material can be applied to coating materials for nuclear reactor construction or other structural materials requiring high reliability.” The research project received support from National Research Foundation, Global Frontier Program, KAIST EEWS-KINC Program and KISTI Supercomputer and was a collaborative effort with KISTI (Korea Institute of Science and Technology Information), KBSI (Korea Basic Science Institute), Stanford University, and Columbia University. A schematic diagram shows the structure of metal-graphene multi-layers. The metal-graphene multi-layered composite materials, containing a single-layered graphene, block the dislocation movement of graphene layers, resulting in a greater strength in the materials.
2013.08.23
View 12068
A magnetic pen for smartphones adds another level of conveniences
Utilizing existing features on smartphones, the MagPen provides users with a compatible and simple input tool regardless of the type of phones they are using. A doctoral candidate at the Korea Advanced Institute of Science and Technology (KAIST) developed a magnetically driven pen interface that works both on and around mobile devices. This interface, called the MagPen, can be used for any type of smartphones and tablet computers so long as they have magnetometers embedded in. Advised by Professor Kwang-yun Wohn of the Graduate School of Culture Technology (GSCT) at KAIST, Sungjae Hwang, a Ph.D. student, created the MagPen in collaboration with Myung-Wook Ahn, a master"s student at the GSCT of KAIST, and Andrea Bianchi, a professor at Sungkyunkwan University. Almost all mobile devices today provide location-based services, and magnetometers are incorporated in the integrated circuits of smartphones or tablet PCs, functioning as compasses. Taking advantage of built-in magnetometers, Hwang"s team came up with a technology that enabled an input tool for mobile devices such as a capacitive stylus pen to interact more sensitively and effectively with the devices" touch screen. Text and command entered by a stylus pen are expressed better on the screen of mobile devices than those done by human fingers. The MagPen utilizes magnetometers equipped with smartphones, thus there is no need to build an additional sensing panel for a touchscreen as well as circuits, communication modules, or batteries for the pen. With an application installed on smartphones, it senses and analyzes the magnetic field produced by a permanent magnet embedded in a standard capacitive stylus pen. Sungjae Hwang said, "Our technology is eco-friendly and very affordable because we are able to improve the expressiveness of the stylus pen without requiring additional hardware beyond those already installed on the current mobile devices. The technology allows smartphone users to enjoy added convenience while no wastes generated." The MagPen detects the direction at which a stylus pen is pointing; selects colors by dragging the pen across smartphone bezel; identifies pens with different magnetic properties; recognizes pen-spinning gestures; and estimates the finger pressure applied to the pen. Notably, with its spinning motion, the MagPen expands the scope of input gestures recognized by a stylus pen beyond its existing vocabularies of gestures and techniques such as titling, hovering, and varying pressures. The tip of the pen switches from a pointer to an eraser and vice versa when spinning. Or, it can choose the thickness of the lines drawn on a screen by spinning. "It"s quite remarkable to see that the MagPen can understand spinning motion. It"s like the pen changes its living environment from two dimensions to three dimensions. This is the most creative characteristic of our technology," added Sungjae Hwang. Hwang"s initial research result was first presented at the International Conference on Intelligent User Interfaces organized by the Association for Computing Machinery and held on March 19-22 in Santa Monica, the US. In the next month of August, the research team will present a paper on the MagPen technology, entitled "MagPen: Magnetically Driven Pen Interaction On and Around Conventional Smartphones" and receive an Honorable Mention Award at the 15th International Conference on Human-Computer Interaction with Mobile Devices and Services (MobileHCI 2013) to be held in Germany. In addition to the MagPen, Hwang and his team are conducting other projects to develop different types of magnetic gadgets (collectively called "MagGetz") that include the Magnetic Marionette, a magnetic cover for a smartphone, which offers augmented interactions with the phone, as well as magnetic widgets such as buttons and toggle interface. Hwang has filed ten patents for the MagGetz technology. Youtube Links: http://www.youtube.com/watch?v=NkPo2las7wc, http://www.youtube.com/watch?v=J9GtgyzoZmM
2013.07.25
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Late Dr. Ryu Geun Chul's Achievements and Generous Contributions
First Doctor in the field of Korean Traditional Medicine The late Dr. Ryu was born in 1926 and is the father figure of Korea’s Traditional Medicine and is its First Doctor (1976 Kyung Hee University), and was the vice-professor of Kyung Hee University of Medicine, Vice-Director of Kyung Hee Institute of Korean Traditional Medicine, and was the first chairman of the Association of Korea Oriental Medicine. He developed the painless acupuncture administering device for the first time in Korea in 1962, and succeeded in anesthetizing a patient for cesarean procedure using acupuncture in 1972. He even was the first to receive a medical engineering doctorate degree from the Moscow National Engineering School in April of 1996 and developed a stroke rehabilitation machine. Korea’s Most Generous Donor Dr. Ryu surprised the world by donating 57.8billion Won worth of real estate to KAIST in August of 2008. Dr. Ryu revealed that his reason for donating such a huge sum to KAIST was due to its focused students giving him the belief that the future of Korea is at KAIST and that the development of science and technology is necessary for Korea to develop into a world class nation and KAIST is the institute most suitable to lead Korea in the field. Dr. Ryu lived on KAIST campus after donating his entire fortune and even established ‘KAIST scholars and spacemen health research center’ and ‘Dr. Ryu Health Clinic’ as he also wanted to donate his knowledge. Even when he was a professor at Moscow National Engineering University in the late 1990s he carried out free medical work throughout Korea and in recognition of his devoted work, he was named honorary citizen from Chun Ahn city, San Chung city, and DaeJeon city. In 2007 he donated 450million Won to Cheon Dong Elementary School in Chun Ahn city to build a gymnasium and an indoor golf practice range. Role as Science and Technology Public Relations Officer Dr. Ryu volunteered to numerous lectures and interviews after donation to advertise science and technology. His belief that the development of science and technology is necessary for Korea’s development was the driving force behind his efforts at increasing interest and support for the field of science and technology. In addition, through interviews with MBC, KBS, SBS, KTV, Joong Ang Newspapers, Dong Ah Newspaper and other media mediums, Dr. Ryu improved the public perception on donations whilst increasing the pride of scientists and researchers by highlighting their importance and the importance of science and technology. In recognition of Dr. Ryu’s efforts, he received the 43rd Science Day Science and Technology Creation Award, 2010 MBC Social Service Special Award, and 2010 ‘Proud Chung Cheong Citizen’ Award.
2011.03.22
View 12224
Professor Min Beom Ki develops metamaterial with high index of refraction
Korean research team was able to theoretically prove that a metamaterial with high index of refraction does exist and produced it experimentally. Professor Min Beom Ki, Dr. Choi Moo Han, and Doctorate candidate Lee Seung Hoon was joined by Dr. Kang Kwang Yong’s team from ETRI, KAIST’s Professor Less Yong Hee’s team, and Seoul National University’s Professor Park Nam Kyu’s team. The research was funded by the Basic Research Support Program initiated by the Ministry of Education, Science, and Technology and Korea Research Federation. The result of the research was published in ‘Nature’ magazine and is one of the few researches carried out by teams composed entirely of Koreans. Metamaterials are materials that have physical properties beyond those materials’ properties that are found in nature. It is formed not with atoms, but with synthetic atoms which have smaller structures than wavelengths. The optical and electromagnetic waves’ properties of metamaterials can be altered significantly which has caught the attention of scientists worldwide. Professor Min Beom Ki’s team independently designed and created a dielectric metamaterial with high polarization and low diamagnetism with an index of refraction of 38.6, highest synthesized index value. It is expected that the result of the experiment will help develop high resolution imaging system and ultra small, hyper sensitive optical devices.
2011.02.23
View 13139
Prof. Choi Unveils Method to Improve Emission Efficiency of OLED
A KAIST research team led by Prof. Kyung-Cheol Choi of the School of Electrical Engineering & Computer Science discovered the surface plasmon-enhanced spontaneous emission based on an organic light-emitting device (OLED), a finding expected to improve OLED"s emission efficiency, KAIST authorities said on Thursday (July 9). For surface plasmon localization, silver nanoparticles were thermally deposited in a high vacuum on cathode. Since plasmons provide a strong oscillator decay channel, time-resolved photoluninescene (PL) results displayed a 1.75-fold increased emission rate, and continuous wave PL results showed a twofold enhanced intensity. "The method using surface plasmon represents a new technology to enhance the emission efficiency of OLED. It is expected to greatly contribute to the development of new technologies in OLED and flexible display, as well as securing original technology," Prof. Choi said. The finding was published in the April issue of Applied Physics Letters and the June 25 issue of Optics Express. It will be also featured as the research highlight of the August issue of Nature Photonics and Virtual Journal of Ultrafast Science.
2009.07.09
View 17360
Industrial Design Senior Wins Top Award at International Forum Design
Sung-Joon Kim, a senior at the Department of Industrial Design, KAIST, has won the highest award at the International Forum Design held in Hanover, Germany, university sources said on Monday (April 13). At the design exhibition held in February under the theme of "life, live, work," Kim presented "Rescue Stick," a portable life saving equipment and "Recovery Arm Sling," a medical treatment device, in cooperation with three students from other Korean universities. Both entries were included among the 15 works selected as the top designs. The design competition has been organized by iF International Forum Design, known as one of the world"s three leading design exhibitions. Kim, leader of the team, received the prize at the awarding ceremony held in Nuremberg on March 24. The award-winning designs were on display at the design fair of the Altenpflege + Propflege, a nursing care exhibition, in the same city on March 24-26.
2009.04.15
View 9728
KAIST Research Team Unveils Method to Fabricate Photonic Janus Balls
A research team led by Prof. Seung-Man Yang of the Department of Chemical and Biomolecular Engineering has found a method to fabricate photonic Janus balls with isotropic structural colors. The finding draws attention since the newly-fabricated photonic balls may prove useful pigments for the realization of e-paper or flexible electronic displays. The breakthrough was published in the Nov. 3 edition of the science journal "Advanced Materials." The Nov. 6 issue of "Nature" also featured it as one of the research highlights under the title of "Future Pixels." Prof. Yang"s research team found that tiny marbles, black on one side and colored on the other, can be made by "curing" suspensions of silica particles with an ultraviolet lamp. When an electric field is applied, the marbles line up so that the black sides all face upwards, which suggests they may prove useful pigments for flexible electronic displays. The researchers suspended a flow of carbon-black particles mixed with silica and a transparent or colored silica flow in a resin that polymerizes under ultraviolet light. They then passed the mixture through a tiny see-through tube. The light solidified the silica and resin as balls with differently colored regions, each about 200 micrometers in diameter. Over the last decades, the development of industrial platforms to artificially fabricate structural color pigments has been a pressing issue in the research areas of materials science and optics. Prof. Yang, who is also the director of the National Creative Research Initiative Center for Integrated Optofluidic Systems, has led the researches focused on fabrication of functional nano-materials through the process of assembling nano-building blocks into designed patterns. The "complementary hybridization of optical and fluidic devices for integrated optofluidic systems" research was supported by a grant from the Creative Research Initiative Program of the Ministry of Education, Science & Technology.
2008.11.12
View 11112
Home-Grown Transparent Thin Film Transistor Developed
KAIST, Aug. 6, 2008 -- A KAIST research team led by Profs. Jae-Woo Park and Seung-Hyup Yoo of the Electrical Engineering Division has developed a home-grown technology to create transparent thin film transistor using titanium dioxide., university authorities said.The KAIST team made the technological advance in collaboration with the LCD Division of Samsung Electronics and the Techno Semichem Co., a local LCD equipment maker. Transparent thin film transistor continues to enjoy a wealth of popularity and intensive research interest since it is used in producing operating circuits including transparent display, active-matrix OLED (AMOLED) display and flexible display. The new technology is significant in that it is based on a titanium dioxide, the first such attempt in the world, while the technologies patented by the United States and Japan are based on ZnO. Researchers will continue to work on securing technological reliability and developing a technology to mass-produce in a large-scale chemical vapor deposition equipment for the next couple of years. "The development of technology to produce transparent thin film transistor will help Korean LCD makers reduce its dependence on foreign technologies, as well as maintain Korea"s status as a leader of the world"s display industry," said Prof. Park. KAIST has applied for local patent registration of the technology and the process is expected to complete by this October or November. International patents have been also applied for in the U.S., Japan and Europe. The new technology was introduced in the latest edition of the Electron Device Letters, a journal published by the Institute of Electrical and Electronics Engineers or IEEE, a New York-based international non-profit, professional organization for the advancement of technology related to electricity. It will be presented at the International Display Workshop 2008 on Dec. 5 in Niigata, Japan.
2008.08.07
View 12493
Three Professors Selected as IEEE Fellows
Three Korea Advanced Institute of Science and Technology (KAIST)’s professors, Ju-Jang Lee, Yong-Hee Lee, and Hoi-Jun Yoo, were selected as a part of the 2008 Institute of Electrical and Electronics Engineers, Inc (IEEE)’s “Fellows.” A Fellow is the highest level of membership given only to those “with an extraordinary record of accomplishments” in their field of study. Although some IEEE memberships can be gained freely by all, the Fellow status is bestowed only by the IEEE Board of Directors. Professor Ju-Jang Lee was awarded the Fellow status “for contributions to intelligent robust control and robotics.” Robust control is a system’s stable maintenance under many inputs in a dynamic environment. A part of KAIST’s Electrical Engineering Department, Professor Ju-Jang Lee has conducted successful research in these fields, and has published 538 papers. He also holds many patents in and outside of the country, and is the General Chair for two upcoming IEEE conferences in 2008 and 2009. Professor Yong-Hee Lee of KAIST’s Physics Department was recognized for his “contributions to photonic devices based upon vertical cavity surface emitting lasers and photonic crystals.” Photonic devices are those that allow the practical use of photons, and photon crystals are structures that affect the motion of photons. Professor Yong-Hee Lee is an expert in the field of Photonics and his works have been cited over 2500 times. He is also an outstanding speaker, giving over 30 lectures in front of international audiences in the past 5 years, and receiving The Distinguished Lecturer’s Award from IEEE. Professor Hoi-Jun Yoo was granted the prestigious Fellow status for his “contributions to low-power and high-speed VLSI design.” VLSI stands for ‘very large scale integration’ and refers to the skill for packing a huge number of semiconductors on an integrated circuit. Professor Lee’s Fellow status is noteworthy in that he studied, worked, and researched solely in Korea. He is also the youngest of the three KAIST professors to be granted membership in the class of 2008 Fellowship. IEEE also recognized Professor Yoo as the most frequent publisher during the past 8 years. IEEE, originally concentrating on Electric Engineering, has now branched into many related fields. It is a nonprofit organization, and its aim is to be the world"s leading professional association for the advancement of technology. For its Fellow Class of 2008, 295 members were chosen; which is less that 0.1% of their total members.By KAIST Herald on December, 2007
2007.12.21
View 14776
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