Science
-
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 7554 -
Structural Insight into the Molecular Mechanism of PET Degradation
A KAIST metabolic engineering research team has newly suggested a molecular mechanism showing superior degradability of poly ethylene terephthalate (PET).
This is the first report to simultaneously determine the 3D crystal structure of Ideonella sakaiensis PETase and develop the new variant with enhanced PET degradation.
Recently, diverse research projects are working to address the non-degradability of materials. A poly ethylene terephthalate (PET)-degrading bacterium called Ideonella sakaiensis was recently identified for the possible degradation and recycling of PET by Japanese team in Science journal (Yoshida et al., 2016). However, the detailed molecular mechanism of PET degradation has not been yet identified.
The team under Distinguished Professor Sang Yup Lee of the Department of Chemical and Biomolecular Engineering and the team under Professor Kyung-Jin Kim of the Department of Biotechnology at Kyungpook National University conducted this research. The findings were published in Nature Communications on January 26.
This research predicts a special molecular mechanism based on the docking simulation between PETase and a PET alternative mimic substrate. Furthermore, they succeeded in constructing the variant for IsPETase with enhanced PET-degrading activity using structural-based protein engineering.
It is expected that the new approaches taken in this research can be background for further study of other enzymes capable of degrading not only PET but other plastics as well.
PET is very important source in our daily lives. However, PET after use causes tremendous contamination issues to our environment due to its non-biodegradability, which has been a major advantage of PET. Conventionally, PET is disposed of in landfills, using incineration, and sometimes recycling using chemical methods, which induces additional environmental pollution. Therefore, a new development for highly-efficient PET degrading enzymes is essential to degrade PET using bio-based eco-friendly methods.
Recently, a new bacterial species, Ideonella sakaiensis, which can use PET as a carbon source, was isolated. The PETase of I. sakaiensis (IsPETase) can degrade PET with relatively higher success than other PET-degrading enzymes. However, the detailed enzyme mechanism has not been elucidated, hindering further studies.
The research teams investigated how the substrate binds to the enzyme and which differences in enzyme structure result in significantly higher PET degrading activity compared with other cutinases and esterases, which make IsPETase highly attractive for industrial applications toward PET waste recycling.
Based on the 3D structure and related biochemical studies, they successfully predicted the reasons for extraordinary PET degrading activity of IsPETase and suggested other enzymes that can degrade PET with a newly-classified phylogenetic tree. The team proposed that 4 MHET moieties are the most properly matched substrates due to a cleft on structure even with the 10-20-mers for PET. This is meaningful in that it is the first docking simulation between PETase and PET, not its monomer.
Furthermore, they succeeded in developing a new variant with much higher PET-degrading activity using a crystal structure of this variant to show that the changed structure is better to accommodate PET substrates than wild type PETase, which will lead to developing further superior enzymes and constructing platforms for microbial plastic recycling.
Professor Lee said, “Environmental pollution from plastics remains one of the greatest challenges worldwide with the increasing consumption of plastics. We successfully constructed a new superior PET-degrading variant with the determination of a crystal structure of PETase and its degrading molecular mechanism. This novel technology will help further studies to engineer more superior enzymes with high efficiency in degrading. This will be the subject of our team’s ongoing research projects to address the global environmental pollution problem for next generation.”
This work was supported by the Technology Development Program to Solve Climate Changes on Systems Metabolic Engineering for Biorefineries (NRF-2012M1A2A2026556 and NRF-2012M1A2A2026557) from the Ministry of Science and ICT through the National Research Foundation of Korea. Further Contact: Dr. Sang Yup Lee, Distinguished Professor, KAIST, Daejeon, Korea (leesy@kaist.ac.kr, +82-42-350-3930)
(Figure: Structural insight into the molecular mechanism of poly(ethylene terephthalate) degradation and the phylogenetic tree of possible PET degrading enzymes. This schematic diagram shows the overall conceptualization for structural insight into the molecular mechanism of poly (ethylene terephthalate) degradation and the phylogenetic tree of possible PET degrading enzymes.)
2018.01.31 View 8344 -
Developing Flexible Vertical Micro LED
A KAIST research team led by Professor Keon Jae Lee from the Department of Materials Science and Engineering and Professor Daesoo Kim from the Department of Biological Sciences has developed flexible vertical micro LEDs (f-VLEDs) using anisotropic conductive film (ACF)-based transfer and interconnection technology. The team also succeeded in controlling animal behavior via optogenetic stimulation of the f-VLEDs.
Flexible micro LEDs have become a strong candidate for the next-generation display due to their ultra-low power consumption, fast response speed, and excellent flexibility. However, the previous micro LED technology had critical issues such as poor device efficiency, low thermal reliability, and the lack of interconnection technology for high-resolution micro LED displays.
The research team has designed new transfer equipment and fabricated a f-VLED array (50ⅹ50) using simultaneous transfer and interconnection through the precise alignment of ACF bonding process. These f-VLEDs (thickness: 5 ㎛, size: below 80 ㎛) achieved optical power density (30 mW/mm2) three times higher than that of lateral micro LEDs, improving thermal reliability and lifetime by reducing heat generation within the thin film LEDs.
These f-VLEDs can be applied to optogenetics for controlling the behavior of neuron cells and brains. In contrast to the electrical stimulation that activates all of the neurons in brain, optogenetics can stimulate specific excitatory or inhibitory neurons within the localized cortical areas of the brain, which facilitates precise analysis, high-resolution mapping, and neuron modulation of animal brains. (Refer to the author’s previous ACS Nano paper of “Optogenetic Mapping of Functional Connectivity in Freely Moving Mice via Insertable Wrapping Electrode Array Beneath the Skull.” )
In this work, they inserted the innovative f-VLEDs into the narrow space between the skull and the brain surface and succeeded in controlling mouse behavior by illuminating motor neurons on two-dimensional cortical areas located deep below the brain surface.
Professor Lee said, “The flexible vertical micro LED can be used in low-power smart watches, mobile displays, and wearable lighting. In addition, these flexible optoelectronic devices are suitable for biomedical applications such as brain science, phototherapeutic treatment, and contact lens biosensors.”
He recently established a startup company ( FRONICS Inc. ) based on micro LED technology and is looking for global partnerships for commercialization. This result entitled “ Optogenetic Control of Body Movements via Flexible Vertical Light-Emitting Diodes on Brain Surface ” was published in the February 2018 issue of Nano Energy.
Figure 1. Comparison of μ-LEDs Technology
2018.01.29 View 12078 -
Three Professors Named KAST Fellows
(Professor Dan Keun Sung at the center)
(Professor Y.H. Cho at the center)
(Professor K.H. Cho at the center)
The Korean Academy of Science and Technology (KAST) inducted three KAIST professors as fellows at the New Year’s ceremony held at KAST on January 12. They were among the 24 newly elected fellows of the most distinguished academy in Korea. The new fellows are Professor Dan Keun Sung of the School of Electrical Engineering, Professor Kwang-Hyun Cho of the Department of Bio and Brain Engineering, and Professor Yong-Hoon Cho of the Department of Physics.
Professor Sung was recognized for his lifetime academic achievements in fields related with network protocols and energy ICT. He also played a crucial role in launching the Korean satellites KITSAT-1,2,3 and the establishment of the Satellite Technology Research Center at KAIST.
Professor Y.H.Cho has been a pioneer in the field of low-dimensional semiconductor-powered quantum photonics that enables quantum optical research in solid state. He has been recognized as a renowned scholar in this field internationally.
Professor K.H.Cho has conducted original research that combines IT and BT in systems biology and has applied novel technologies of electronic modeling and computer simulation analysis for investigating complex life sciences. Professor Cho, who is in his 40s, is the youngest fellow among the newly inducted fellows.
2018.01.16 View 11698 -
CLKIP Bearing Fruit in China
The Chongqing Liangjiang KAIST International Program (CLKIP) is rapidly gaining steam in China. CLKIP, an educational program operated in Chongqing internationally by KAIST since 2015, offers two majors, Electronic Information Engineering and Computer Science and Technology, applying the same curriculum as at KAIST.
To operate the program, KAIST assigns professors from the School of Electrical Engineering and the School of Computing to the program every year. They are in charge of one-third of the major courses, and transfer KAIST’s educational curriculum and know-how.
A total of 13 professors from Chongqing University of Technology (CQUT) have received or are receiving training on advanced education methodologies and technical know-how, including an on and offline integrated learning program, called Education 4.0 and large-scale internet open learning.As CLKIP is gaining in popularity, the number of students for its undergraduate courses keeps increasing, from 66 in 2015 to 172 in 2016 and 200 students in 2017, achieving the student volume for enrollment annually.
CLKIP selected seven exchange undergraduate students and five dual-degree students this fall, and they are currently studying in KAIST for either one semester or one full year.
CLKIP is located in Chongqing, one of the major direct-controlled municipalities and a focal point for notable government projects. The Korea-China industrial zone is also located in this area.
Considering its location, CLKIP is more than just an international programs for educational cooperation. The program will provide opportunities to cooperate with Korean enterprises including Hyundai, SK Hynix, LG Chem and Hankook Tire. While cooperating in research and development as well as technical assistance, KAIST hopes that these enterprises will play a bridging role for KAIST alumni entering the Chinese market.
President Sung-Chul Shin said, “The success of CLKIP shows that KAIST programs for fostering future manpower and developing cutting-edge technologies do work in other countries. Based on this case, KAST will put more effort into transferring our innovative education systems abroad. We are also pushing ahead to establish a joint institute between KAIST and CQUT by 2018, which will become a foundation for facilitating the entry of KAIST’s cutting-edge technologies into the Chinese market.”
“KAIST aims to become an entrepreneurial university that creates value through technology commercialization. In this sense, KAIST plans to transfer advanced technologies to domestic and international companies located in the Liangjiang district,” he added.
2017.12.12 View 9326 -
Professor Dong Ho Cho Awarded at the Haedong Conference 2017
Professor Dong Ho Cho of the School of Electrical Engineering at KAIST received an award at the 13th Haedong Conference 2017 in Seoul on the first of December.
The Korean Institute of Communications and Information Sciences recognized Professor Cho for his significant contributions in the field of mobile communication networks. He has carried out groundbreaking research on mobile systems, including architecture, protocols, algorithms, optimization, and efficiency analysis.
As a result, he has produced 73 papers in renowned international journals, 138 papers at international conferences, and filed 52 international patents and 121 domestic patents. In addition, he transferred 14 of the patents he filed to Korean and international companies.
2017.12.07 View 5180 -
Scientist of November, Professor Hyung Jin Sung
Professor Hyung Jin Sung from the Department of Mechanical Engineering at KAIST received a ‘Science and Technology Award of the Month’ given by the Ministry of ICT and Science and the National Research Foundation of Korea for November 2017. He developed technology that can exquisitely control a micrometer-scaled liquid drop on a dime-sized lab-on-a-chip. With his work, he was recognized for reinforcing research capability on microfluidics.
Lab-on-a-chip is an emerging experiment and diagnostic technology in the form of a bio-microchip that facilitates complex and various experiments with only a minimal sample size required. This technology draws a lot of attention not only from medical and pharmaceutical areas, but also the health and environmental field. The biggest problem was that technology for the temperature control of a fluid sample, which is one of the core technologies in microfluidics, has low accuracy. This limit had to be overcome in order to use the lab-on-a-chip more widely.
Professor Sung developed an acoustic and thermal method which controls the temperature of a droplet quickly and meticulously by using sound and energy. This is a thermal method that uses heat generated during the absorption of an acoustic wave into viscoelastic substances. It facilitates a rapid heating rate and spatial-temporal temperature control, allowing heating in desired areas. In addition, Professor Sung applied his technology to polymerase chain reactions, which are used to amplify DNA.
Through this experiment, he successfully shortened the reaction time from 1-2 hours to only three minutes, making this a groundbreaking achievement.
Professor Sung said, “My research is significant for enhancing the applicability of microfluidics. I expect that it will lead to technological innovations in healthcare fields including biochemistry, medical checkups, and new medicine development.”
2017.11.03 View 8094 -
KAIST and KOICA Invited Dominican Republic Officials for Workshop
KAIST will host a two-week workshop for Dominican Republic officials and scholars in collaboration with KOICA (Korea International Cooperation Agency) beginning October 23 at KAIST.
The workshop aims to encourage academia-industry cooperation as one of the Projects for Human Resource Development for Science and Technology at KOICA. Dominican participants including the assistant minister of the Ministry of Higher Education, Science and Technology (MESCYT) and deans of engineering colleges at major universities will enjoy lectures from experts and visit enterprises known for excellent academia-industry collaboration.
According to the Center for Overseas Development, at which Professor WonJoon Kim in the School of Business and Technology Management at KAIST holds the position of director, the workshop is designed to develop human resources in the science and technology (S&T) area, share knowledge on research and development in the field of academia-industry cooperation, and help the participants acquire know-how for managing partnerships between related organizations and industries.
During the workshop, KAIST plans to transfer know-how and share knowledge on its academia-industry cooperation R&D system, in hopes that the workshop will help the Dominican Republic foster its manpower in higher education. The workshop organizers hope that the officers and scholars will be able to apply what they will learn for establishing and carrying out detailed action plans for academia-industry cooperation policies in an effective manner.
“This workshop provides an opportunity to learn about the development of S&T in Korea, academia-industry cooperation R&D, and fostering manpower in advanced S&T. Through the knowledge sharing, we can have a better understanding of academia-industry cooperation as well as education on advanced manpower,” said Pedro Antonio Eduardo, the assistant minister of MESCYT.
He added, “I hope that this workshop will further detailed cooperation between the two countries for Korean high-tech enterprises’ overseas expansion and advanced manpower education. The development model in Korea has many essential elements, so learning its engine for growth and polytechnic manpower education will help develop my country’s industry sector.”
The Project for Human Resource Development for Science and Technology is one of the official development assistance projects running from last year until 2019. It promotes R&D activities for S&T in the Dominican Republic, encouraging academia-industry cooperation by improving trainers in charge of advanced manpower education.
2017.10.30 View 6654 -
Distinguished Professor Lee Named International Fellow of the CAS
Distinguished Professor Sang Yup Lee from the Department of Chemical and Biomolecular Engineering at KAIST was awarded the title of distinguished professor and international fellow from the Chinese Academy of Sciences (CAS), and honorary professor from its affiliated organization the Tianjin Institute of Industrial Biotechnology (TIB).
The CAS recognized Distinguished Professor Lee for his significant contributions to biotechnology. He has made significant pioneering academic achievements in the area of systems metabolic engineering, which produces useful chemicals from microorganisms. Not only did he develop the first and best source technology in that field, but also came out with processes for the production of biofuel and environmentally-friendly chemicals.”
As a global leader in systems metabolic engineering, Distinguished Professor Lee has also been appointed as an honorary professor at Jiangnan University in Wuxi, China.
Distinguished Professor Lee was listed in the ‘Top 20 Translational Researchers of 2014’ selected by the renowned international journal Nature Biotechnology. Moreover, he was the first Asian recipient of the James E. Bailey Award in 2016 and Marvin J. Johnson Award in 2012, which are given to scholars in the field of biotechnology.
He is also one of 13 global scientists who are foreign members of the renowned academic societies the National Academy of Engineering and the National Academy of Sciences in the US. Furthermore, he received the ‘2017 Korea Best Scientist Award’ from the president of Korea in July. Finally, his founding field, systems metabolic engineering, was chosen as one of the ‘Top 10 Emerging Technologies of 2016’ by the World Economic Forum.
The Chinese Academy of Sciences, established in November 1949, is an academic organization that carries out research on basic sciences and natural sciences in China. It defined its science and technology system to include the fields of basic sciences, natural sciences, and high technology. While having a base in Beijing, its branch academies are located in 12 main cities along with 117 affiliates and 100 national key labs.
2017.10.26 View 9507 -
Development of a Highly-Accurate Computational Model of Human Metabolism
A research team from KAIST developed a computational framework that enables the reconstruction of a comprehensive computational model of human metabolism, which allows for an accurate prediction of personal metabolic features (or phenotypes).
Understanding personal metabolic phenotypes allows us to design effective therapeutic strategies for various chronic and infectious diseases. A human computational model called the genome-scale metabolic model (GEM) contains information on thousands of metabolic genes and their corresponding reactions and metabolites, and has played an important role in predicting metabolic phenotypes. Although several versions of human GEMs have been released, they had room for further development, especially as to incorporating biological information coming from a human genetics mechanism called “alternative splicing.” Alternative splicing is a genetic mechanism that allows a gene to give rise to multiple reactions, and is strongly associated with pathology.
To tackle this problem, Jae Yong Ryu (a Ph.D. student), Dr. Hyun Uk Kim (Research Fellow), and Distinguished Professor Sang Yup Lee, all from the Department of Chemical and Biomolecular Engineering at KAIST, developed a computational framework that systematically generates metabolic reactions, and adds them to the human GEM. The resulting human GEM was demonstrated to accurately predict metabolic phenotypes under varied environmental conditions. The research results were published online in Proceedings of the National Academy of Sciences (PNAS) on October 24, 2017, under the title “Framework and resource for more than 11,000 gene-transcript-protein-reaction associations in human metabolism.”
The research team first updated the biological contents of a previous version of the human GEM. The updated biological contents include metabolic genes and their corresponding metabolites and reactions. In particular, metabolic reactions catalyzed by already-known protein isoforms were additionally incorporated into the human GEM; protein isoforms are multiple variants of proteins generated from individual genes through the alternative splicing process. Each protein isoform is often responsible for the operation of a metabolic reaction. Although multiple protein isoforms generated from one gene can play different functions by having different sets of protein domains and/or subcellular localizations, such information was not properly considered in previous versions of human GEMs.
Upon the initial update of the human GEM, named Recon 2M.1, the research team subsequently implemented a computational framework that systematically generates information on Gene-Transcript-Protein-Reaction Associations (GeTPRA) in order to identify protein isoforms that were previously not identified. This framework was developed in this study. As a result of the implementation of the framework for GeTPRA, more than 11,000 GeTPRA were automatically predicted, and thoroughly validated. Additional metabolic reactions were then added to Recon 2M.1 based on the predicted GeTPRA for the previously uncharacterized protein isoforms; Recon 2M.1 was renamed Recon 2M.2 from this upgrade.
Finally, Recon 2M.2 was integrated with 446 sets of personal biological data (RNA-Seq data) in order to build patient-specific cancer models. These patient-specific cancer models were used to predict cancer metabolism activities and anticancer targets.
The development of a new version of human GEMs along with the computational framework for GeTPRA is expected to boost studies in fundamental human genetics and medicine. Model files of the human GEMs Recon 2M.1 and 2M.2, a full list of the GeTPRA and the source code for the computational framework to predict the GeTPRA are all available as part of the publication of this study.
Distinguished Professor Lee said, “The predicted GeTPRA from the computational framework is expected to serve as a guideline for future experiments on human genetics and biochemistry, whereas the resulting Recon 2M.2 can be used to predict drug targets for various human diseases.”
This work was supported by the Technology Development Program to Solve Climate Changes on Systems Metabolic Engineering for Biorefineries (NRF-2012M1A2A2026556 and NRF-2012M1A2A2026557) from the Ministry of Science and ICT through the National Research Foundation (NRF) of Korea.
(Figure 1:A scheme of Recon 2M.1 development and its use in reconstructing personal genome-scale metabolic models (GEMs). (A) A concept of alternative splicing of human genes and its use in Gene-Transcript-Protein-Reaction Associations (GeTPRA) of Recon 2M.1. (B) A procedure of systematic refinement of the Recon 2Q. Recon 2Q is one of the previously released human GEMs. Biochemically inconsistent reactions include unbalanced, artificial, blocked, and/or redundant reactions. Iterative manual curation was conducted while validating the Recon 2M.1. (C) Reconstruction of cancer patient-specific GEMs using Recon 2M.1 for further simulation studies. In this study, personal biological data (RNA-Seq data) were obtained from The Cancer Genome Atlas (TCGA; https://cancergenome.nih.gov/ ) across the ten cancer types.
(Figure 2: Computational framework for the systematic generation of Gene-Transcript-Protein-Reaction Associations (GeTPRA; red box in the flowchart). Peptide sequences of metabolic genes defined in Recon 2M.1 were retrieved from a database called Ensembl. EC numbers and subcellular localizations of all the protein isoforms of metabolic genes in Recon 2M.1 were predicted using software programs EFICAz2.5 and Wolf PSort, respectively. Information on the newly predicted GeTPRA was systematically incorporated into the Recon 2M.1, thereby resulting in Recon 2M.2.)
2017.10.25 View 8635 -
Postech-KAIST Rivalry Heats Up at the 16th Science War
The 16th Postech-KAIST Science War wrapped up its two-day rivals’ duel at the KAIST campus in Daejeon on September 23. The event was established in 2002 to build a close tie between the two renowned universities for science and technology, and to provide students with an opportunity to demonstrate their talents and abilities.
On September 21, a convoy of red Postech buses carrying more than 650 athletes, students, and supporters arrived at the KAIST campus in Daejeon. The two teams competed in eight events including both online and sports event.
The night before the actual games started, cheerleading teams from both Postech Cheero and KAIST ELKA kicked off the event.
1st Day (September 22)
The hacking tournament marked the beginning of the Science War. The event started at nine in the morning. Both teams had to solve four problems within 12 hours.
While the fierce hacking competition was underway, school music bands, including Twenties Dreams, opened up the event with beautiful voices.
The soccer game took place in the university stadium. The KAIST soccer team brought the first win to KAIST, and was their second straight victory in soccer.
At the outdoor theatre, the evening games, including Artificial Intelligence and E-sports (League of Legend) began. After the E-sports, both KAIST’s and Postech’s music and dance clubs showed amazing performances adding more excitement to the event.
Another fun aspect of the event was the ‘evening street food market’. Food trucks and food booths were lined up to satisfy students’ hunger. Talso here were various game booths such as can bowling, balloon darts, and lamp DIY.
2nd Day (September 23)
The baseball team marked the second day of the Science War in the Undergraduate Field. The KAIST team won the game by six runs.
Science quizzes sealed the Postech-KAIST Science War. Although the KAIST team led at the beginning, the Postech team overtook them by getting bonus point answers correct. This game decided Postech winning this year’s Science War.
As a spin-off, a badminton game was held in the Sports Complex and the KAIST team beat the Postech team with ease.
Last but not least, a basketball game was held in the Sports Complex. In the last game of the Science War, the KAIST team wiped away the stain of last year’s defeat.
At the closing ceremony, famous rappers and school music clubs celebrated the last moments of the Science War.
(Jiwon Hwang, Public Relations of the 16th Science War Committee)
(The 16th Science War Committee)
Cheers to the students committees, participants, and supporters who put every ounce of their effort into successfully running the 16th Postech-KAIST Science War.
Day
Category
Winner
Day 1
Hacking
Postech
Soccer
KAIST
Artificial Intelligence
Postech
E-Sports (LoL)
Postech
Day 2
Baseball
KAIST
Science Quizzes
Postech
Badminton (spin-off)
KAIST
Basketball
KAIST
(The final tally for KAIST in the Science Wars was eight wins and six losses)
2017.09.27 View 5561 -
Semiconductor Patterning of Seven Nanometers Technology Using a Camera Flash
A research team led by Professor Sang Ouk Kim in the Department of Materials Science and Engineering at KAIST has developed semiconductor manufacturing technology using a camera flash.
This technology can manufacture ultra-fine patterns over a large area by irradiating a single flash with a seven-nanometer patterning technique for semiconductors. It can facilitate the manufacturing of highly efficient, integrated semiconductor devices in the future.
Technology for the Artificial Intelligence (AI), the Internet of Things (IoTs), and big data, which are the major keys for the fourth Industrial Revolution, require high-capacity, high-performance semiconductor devices. It is necessary to develop lithography technology to produce such next-generation, highly integrated semiconductor devices.
Although related industries have been using conventional photolithography for small patterns, this technique has limitations for forming a pattern of sub-10 nm patterns.
Molecular assembly patterning technology using polymers has been in the spotlight as the next generation technology to replace photolithography because it is inexpensive to produce and can easily form sub-10 nm patterns. However, since it generally takes a long time for heat treatment at high-temperature or toxic solvent vapor treatment, mass production is difficult and thus its commercialization has been limited.
The research team introduced a camera flash that instantly emits strong light to solve the issues of polymer molecular assembly patterning. Using a flash can possibly achieve a semiconductor patterning of seven nanometers within 15 milliseconds (1 millisecond = 1/1,000 second), which can generate a temperature of several hundred degrees Celsius in several tens of milliseconds.
The team has demonstrated that applying this technology to polymer molecular assembly allows a single flash of light to form molecular assembly patterns.
The team also identified its compatibility with polymer flexible substrates, which are impossible to process at high temperatures. Through these findings, the technology can be applied to the fabrication of next-generation, flexible semiconductors.
The researchers said the camera flash photo-thermal process will be introduced into molecular assembly technology and this highly-efficiency technology can accelerate the realization of molecular assembly semiconductor technology.
Professor Kim, who led the research, said, “Despite its potential, molecular assembly semiconductor technology has remained a big challenge in improving process efficiency.” “This technology will be a breakthrough for the practical use of molecular assembly-based semiconductors.”
The paper was published in the international journal, Advanced Materials on August 21 with first authors, researcher Hyeong Min Jin and PhD candidate Dae Yong Park.
The research, sponsored by the Ministry of Science and ICT, was co-led Professor by Keon Jae Lee in the Department of Materials Science and Engineering at KAIST, and Professor Kwang Ho Kim in the School of Materials Science and Engineering at Pusan National University.
(1. Formation of semiconductor patterns using a camera flash)
(Schematic diagram of molecular assembly pattern using a camera flash)
(Self-assembled patterns)
2017.09.18 View 10100