science+and+technology
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Micropatch Made of DNA
Researchers reported the fabrication of microstructure arrays of DNA materials using topographic control. This method provides a platform for forming multiscale hierarchical orientations of soft and biomaterials using a process of simple shearing and controlled evaporation on a patterned substrate. This approach enables the potential of patterning applications using DNA or other anisotropic biomaterials.
DNA is one of the most abundant biomaterials found in all living organisms in nature. It has unique characteristics of fine feature size and liquid crystalline phase, enabling to create various kinds of microstructure DNA arrays. Based on these characteristics, DNA has been used as a building block for “origami” and textile art at the nanometer scale.
A KAIST research team led by Professors Dong Ki Yoon and Hyungsoo Kim fabricated a DNA-based micropatch using the “coffee ring effect” and its multi-angle control technology, which was published online in Nature Communications on June 7.
The research team used cheap DNA material extracted from salmon to realize the micropatch structure with well-aligned knit or ice cream cone shapes. When the DNA material in an aqueous solution is rubbed between two solid substrates while water is evaporating, DNA chains are unidirectionally aligned to make a thin film such as in LCD display devices. The DNA chains can make more complex microstructures such as knit or a texture with ice cream cone shapes when the same procedure is carried out in topographical patterns like microposts (Figure 1). This can be applied to make metamaterials by mixing with functionalized gold nanorods to show plasmonic color.
Plasmon resonance is a phenomenon in which electrons vibrate uniformly on the surface of a substrate made of metal, reacting only to light that matches a specific energy to enhance the clarity and expression of colors. For this, the most important factor is the orientation in which the gold nanorods align. That is, when the rods are aligned side by side in one direction, the optical and electrical characteristics are maximized. The research team focused on this point and made the DNA micropatch as a frame to orient the gold nanorods in a unique shape and fabricated a plasmonic color film (Figure 2).
Professor Yoon said this study is meaningful in that it deals with the evaporation phenomenon, which has not been studied much in the field of polymers and biopolymers in terms of basic science. He explained, “This will also help maximize the efficiency of polymeric materials that can be orientated in coating, 2D, and 3D printing applications. Furthermore, DNA that exists infinitely in nature can be expected to have industrial application value as a new material since it can easily form complexes with other materials as described in this study.”
(Figure 1. The DNA micropatch using topographic control. (a) The experimental scheme.
(b) Enlarged image of (e). (c-e) Different micropatches made of DNA using different shearing directions.)
(Figure 2. The knit-like structures made of DNA-gold nanorod complex. (a,b) Optical
and polarized optical microscopy images. (c-f) Plasmonic colors reflected from aligned DNA-gold nanorod complex depending on the sample rotation.)
2019.07.01 View 32710 -
13 KAIST Faculty Named as Inaugural Members of Y-KAST
The Korean Academy of Science and Technology (KAST) launched the Young Korean Academy of Science and Technology (Y-KAST) and selected 73 scientists as its inaugural members on February 24. Among them, 13 KAIST faculty were recognized as the inaugural members of Y-KAST.
Y-KAIST, made up of distinguished mid-career scientists under the age of 45, will take the leading role in international collaboration as well as innovative agenda-making in science and technology.
The inaugural members include Professor Hyotcherl Ihee of the Department of Chemistry and Dr. Sung-Jin Oh of the Center for Mathematical Challenges at the Korea Institute for Advanced Study (KIAS), affiliated with KAIST. Professor Ihee is gaining wide acclaim in the fields of physics and chemistry, and in 2016, Dr. Oh was the youngest ever awardee of the Presidential Award of Young Scientist.
The other Y-KAIST members are as follows: Professors Haeshin Lee of the Department of Chemistry; Mi Young Kim, Byung-Kwan Cho, and Ji-Joon Song of the Department of Biological Sciences; Song-Yong Kim of the Department of Mechanical Engineering; Sang-il Oum of the Department of Mathematical Sciences; Jung Kyoon Choi of the Department of Bio and Brain Engineering; Seokwoo Jeon, Sang Ouk Kim, and Il-Doo Kim of the Department of Materials Science and Engineering; Jang Wook Choi of the Graduate School of EEWS (Energy, Environment, Water and Sustainability); and Jeong Ho Lee of the Graduate School of Medical Science and Engineering.
The leading countries of the Academy of Science, which include Germany, Sweden, Belgium, Canada, and Japan, have established the Young Academy of Science since 2010 in order to encourage the research activities of their young scientists and to establish a global platform for collaborative research projects through their active networking at home and abroad.
President Myung-Chul Lee of KAST said, “We will spare no effort to connect these outstanding mid-career researchers for their future collaboration. Their networking will make significant impacts toward their own research activities as well as the global stature of Korea’s science and technology R&D.
(Photo caption: Members of Y-KAST pose at the inaugural ceremony of Y-KAST on February 24.)
2017.03.02 View 15403 -
Professor Shin Honored Posthumously for Iridescent Microparticles
(The Late Professor Joong-Hoon Shin (left) and Professor Shin-Hyun Kim)
A research team co-led by Professor Shin-Hyun Kim from the Department of Chemical and Biomolecular Engineering and Professor Jong-Ryul Jeong from the Department of Materials Science and Engineering at Chungnam National University developed iridescent microparticles with a structural color gradient. The research team posthumously dedicated their research to a renowned professor in the field of nanophotonics, the late Professor Joong-Hoon Shin of the Graduate School of Nanoscience and Technology at KAIST. He passed away suddenly in a car accident last September.
The iridescent microparticles, which allow on-demand control over structural color, will be key components for next-generation reflection-mode displays with clear color realization even in direct sunlight.
Materials such as opals, Morpho butterfly wings, and peacock feathers all display beautiful colors without pigment, using regularly-spaced nanostructures. Regularly-spaced nanostructures render color, by selectively reflecting the light of a particular wave through light interference. As such, materials that possess periodic modulation of refractive index at subwavelength scale are referred to as photonic crystals.
In general, photonic crystals are only able to display a single color, so limitations exist when attempting to apply them to reflection-mode displays which call for multiple structural colors. The research team addressed the issue using inspiration from snowflakes stacking in the winter. When snow falls on the surface of a round-shaped structure, the thickness of the snow stacking differs depending on the orientation. Based on this observation, the research team created photonic microparticles with a structural color gradient by depositing two different materials on spherical microparticles.
When some material is deposited on the surface of a sphere, the material on the top is thickest and becomes thinner on the sides. The team alternately deposited titania and silica on the spherical microparticles to form periodic modulation of the refractive index. The thickness of the alternating photonic layers is reduced along the angle from the top, which yields a structural color gradient.
Consequently, the microparticles reflect long-wavelength red light from the top of the sphere and short-wavelength blue light from the side of the sphere. Any color of the visible spectrum can be selected in between the top and side depending on the orientation of the microparticles.
The research team used an external magnetic field as a way to control the orientation of the photonic microparticles and the structural colors. As magnetic iron layer was deposited underneath the alternating photonic layer, it was possible to freely control the orientation of the microparticles using a magnet, thereby allowing control of the color seen by the users.
KAIST doctoral candidate Seung Yeol Lee of the Department of Chemical and Biomolecular Engineering is the first author of this research, with support from the Midcareer Researcher Program of the National Research Foundation and funded by the Ministry of Science, ICT, and Future Planning (MSIP). This research was published in the online edition of Advanced Materials on February 6, 2017.
Figure1: Sets of an OM image of photonic Janus microspheres and an SEM image showing a cross-section of the photonic layers.
Figure 2: A series of schematics and OM images showing the color change depending on the orientation angle of the photonic Janus microsphere.
2017.02.17 View 8050 -
JETS Conference 2017
KAIST and four science and technology research universities in Korea co-hosted a technology start-up fair, the 2017 JETS (Job, Exhibition, Tech Forum, and Startup) Conference January 19 ~20 in the Ryu Geun-chul Sports Complex at KAIST.
Korea’s major science and technology research universities, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Gwangju Institute of Science and Technology (GIST), Pohang University of Science and Technology (Postech), and Ulsan National Institute of Science and Technology (UNIST), held the event in a collaborative effort to educate, inspire, and connect young entrepreneurs, especially those who will launch technology start-ups.
The conference brought entrepreneurs and innovators together who seek ways of working with and supporting start-ups and for their sustainable growth. It also drew aspiring young students and researchers from universities and the government-funded research institutions who are in the process of commercializing their technology. Students from each university’s industry-academia cooperation program who incubated their technology and ideas were key contributors.
At the Tech Forum, entrepreneurship and technology consultation specialists including Joe Jasin, managing director at DNA Investment Partners in the US, the founder of Cyworld Dong-Hyung Lee, and Professor Hawoong Jeong, a complex bio-network specialist from the Department of Physics of KAIST lectured on the ecosystem of start-ups and its trends and development.
The Dean of University-Industry Cooperation at KAIST Joongmyeon Bae said, "We organized this event in collaboration with four major research universities to further encourage technology start-ups from young students and help their ideas and technology bear fruit. We will continue to strive to create an ecosystem of start-ups which works efficiently.”
(Above photo: Founder of the Cyworld, Dong-Hyung Lee gives a lecture at the Tech Forum. Below photo: Students visit exhibition booth of each participating institution.)
2017.01.20 View 10137 -
KAIST Receives a Donation of USD 6.41 Million
“We’ve made a real effort to save our money, but can’t spend it all just on ourselves. Please use it to foster talented students in the field of science, who will enrich our country,” said donors at the donation ceremony held today on campus.
A married couple in their 70s donated their real estate, worth approximately USD 6.41 million, to KAIST on November 16, 2015. Seung-Woong Lee, the husband, and Jeong-Ja Cho, his wife, turned over three properties, including buildings in Seoul and Uijeongbu, to the university.
The couple made a promise to themselves to return their assets back to the Korean society since the beginning of their marriage life. They decided that KAIST was the institution with the most potential to contribute to Korea’s growth. This spring they took that step.
The Lee couple said, “We strove to be frugal to gather such a sum of money. We engaged in all sorts of jobs after we left for Seoul from the countryside when the nation was impoverished.”
Mr. Lee said, “On one snowy winter day, I was riding a bicycle on my way back home. Then I saw a restaurant and, at that moment, I yearned for a bowl of soup in such cold weather. But I just rode past because the whole family could eat with the money that I would spend for the soup.”
Ms. Cho said, “At the beginning, I was rather unhappy with my husband’s very frugal personality. But as time passed, I noticed I had become just like him.” She added, smiling, “I often wandered around the market to get even the smallest discounts, and the shops sometimes refused to sell me the goods.”
Their assets are the result of that work ethic and humility. The couple said, “Today is definitely the happiest day of our life because we would keep our promise. We hope that KAIST will foster outstanding talents in the field of science and technology, students who will advance our nation in the future.”
President Steve Kang of KAIST said, “I would like to express my most sincere gratitude toward to this generous couple who have donated their lifetime assets so willingly to KAIST. Their invaluable support will surely become our springboard to continuously pursue our excellence in science and technology.”
In the picture from left to right are Ms. Jeong-Ja Cho (wife), Mr. Seung-Woong Lee (husband), and President Steve Kang.
2015.11.18 View 3833 -
KAIST Partners with Science-focused Universities in Korea for Student Exchange Programs
KAIST and four science-focused universities in Korea (Pohang University of Science and Technology, Gwangju Institute of Science and Technology, Daegu Gyeongbuk Institute of Science and Technology, and Ulsan National Institute of Science and Technology) agreed to exchange programs during academic semesters including summer and winter terms by signing a memorandum of understanding (MOU) on November 28, 2014. The signing ceremony took place at the KAIST campus with the participation of academic affairs deans from all five universities.
Based on the agreement, KAIST students can take up to 12 credits of coursework at any of the said universities and have unimpeded access to the university facilities during their coursework.
Dean Hyun-Wook Park of Academic Affairs at KASIT said, “Through exchange programs, students can capitalize on each university’s advantages, and this eventually will lead to greater advancement in science and technology in the nation.”
2014.12.08 View 7591 -
Former Minister of Science and Technology, Dr. KunMo Chung, Awarded KAIST Honorary Doctorate
KAIST will confer an honorary doctorate on former minister of Science and Technology, Dr. KunMo Chung, at the 2014 KAIST graduation ceremony on Friday, February, 21.Dr. Chung presented the Survey Report for the Establishment of the Korea Advanced Institute of Science (KAIS) to the United States Agency for International Development (USAID) in 1969. This proposal for nurturing the advanced science technology elite and boost Korean industrial development became the foundation for KAIS, which is now known as KAIST.After passing the KAIS Foundation Law in 1970, Dr. Chung designed the faculty room, secured faculty members, and acquired a $6 million education loan from the USAID. Dr. Chung devoted himself to research and teaching. His first appointment was the position of assistant professor at the University of South Florida, followed by research professor positions at the Princeton Nuclear Fusion Research Center and MIT Nuclear Engineering, and an associate professor position in the Department of Electrophysics at the Polytechnic Institute of New York.When KAIS was founded on Feb. 16, 1971, 31-year-old Dr. KunMo Chung became the provost and a professor in the Electronic and Electrical Science Department where he made outstanding contributions to the development of science and technology in Korea.
2014.02.21 View 9396 -
Op-Ed by Professor David Helfman: Global Science and Education in Korea for the 21st Century
Professor David Helfman from the Department of Biological Sciences and Graduate School of Nanoscience and Technology contributed an op-ed, “Global Science and Education in Korea for the 21st Century, to the Korea Herald on February 20, 2013. For the article, please click the link below:
http://www.koreaherald.com/view.php?ud=20130220000623.
2013.02.26 View 9412 -
Op-Ed by Prof. David Helfman: Global Science and Education in the 21st Century
Professor David Helfman from the Department of Biological Sciences and Graduate School of Nanoscience and Technology(https://sites.google.com/site/cellsignalinglaboratory/home) recently wrote an Op-Ed in the January 2013 issue of Journal of Happy Scientists and Engineers that ispublished by the Ministry of Science, Education and Technology, the Republic of Korea. In the article entitled “Global Science and Education in the 21st Century,” Professor Helfman addressed three important issues in science and education, which will have a great impact for the development of world-leading universities in Korea. For the article, please see the attachment.
2013.01.22 View 10912
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Professor Yoon Dong Ki becomes first Korean to Receive the Michi Nakata Prize
Professor Yoon Dong Ki (Graduate School of Nano Science and Technology) became the first Korean to receive the Michi Nakata Prize from the International Liquid Crystal Society.
The Awards Ceremony was held on the 23rd of August in Mainz, Germany in the 24th Annual International Liquid Crystal Conference.
The Michi Nakata Prize was initiated in 2008 and is rewarded every two years to a young scientist that made a ground breaking discovery or experimental result in the field of liquid crystal. Professor Yoon is the first Korean recipient of the Michi Nakata Prize.
Professor Yoon is the founder of the patterning field that utilizes the defect structure formed by smectic displays. He succeeded in large scale patterning complex chiral nano structures that make up bent-core molecules.
Professor Yoon’s experimental accomplishment was published in the Advanced Materials magazine and the Proc. Natl. Acad. Sci. U.S.A. and also as the cover dissertation of Liquid Crystals magazine.
Professor Yoon is currently working on Three Dimensional Nano Patterning of Supermolecular Liquid Crystal and is part of the World Class University organization.
2012.09.11 View 11280
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Biomimetic reflective display technology developed
Professor Shin Jung Hoon
The bright colors of a rainbow or a peacock are produced by the reflection and interference of light in transparent periodic structures, producing what is called a structural color. These colors are very bright and change according to the viewing angle. On the other hand, the wings of a morpho-butterfly also have structural colors but are predominantly blue over a wide range of angles. This is because the unique structure of the morpho-butterfly’s wings contains both order and chaos.
Professor Shin Jung Hoon’s team from the Department of Physics and the Graduate School of Nanoscience and Technology at KAIST produced a display that mimics the structure of the morpho-butterfly’s wings using glass beads.
This research successfully produced a reflective display (one that reflects external light to project images), which could be used to make very bright displays with low energy consumption. This technology can also be used to make anti-counterfeit bills, as well as coating materials for mobile phones and wallets.
The structure of the morpho-butterfly’s wings seems to be in periodic order at the 1-micrometer level, but contains disorder at the 100-nanometer level. So far, no one had succeeded in reproducing a structure with both order and disorder at the nanometer level.
Professor Shin’s team randomly aligned differently sized glass beads of a few hundred nanometers to create chaos and placed a thin periodic film on top of it using the semiconductor deposition method, thereby creating the morpho-butterfly-like structure over a large area.
This new development produced better color and brightness than the morpho-butterfly wing and even exhibited less color change according to angle. The team sealed the film in thin plastic, which helped to maintain the superior properties whilst making it more firm and paper-like.
Professor Shin emphasized that the results were an exemplary success in the field of biomimetics and that structural colors could have other applications in sensors and fashion, for example.
The results were first introduced on May 3rd in Nature as one of the Research Highlights and will be published in the online version of the material science magazine, Advanced Materials.
This research was jointly conducted by Professor Shin Jung Hoon (Department of Physics / Graduate School of Nanoscience and Technology at KAIST), Professor Park NamKyoo (Department of Electrical and Computer Engineering at Seoul National University), and Samsung Advanced Institute of Technology. The funding was provided by the National Research Foundation of Korea and the Ministry of Education, Science and Technology as part of the World Class University (WCU) project.
Figure 2. The biomimetic film can express many different colors
Figure 3. The biomimetic diplay and a morpho-butterfly
2012.05.07 View 13445