-
Professor Suck-Joo Na Receives the 2016 Humboldt Research Award
The Alexander von Humboldt Foundation, established by the German government in 1953, promotes academic cooperation and exchange among scientists and scholars from Germany and abroad. The foundation has bestowed this year's award to Professor Suck-Joo Na of KAIST's Mechanical Engineering Department in recognition of his lifetime achievements.
Professor Na's main interests are in the fields of arc and laser welding, computational fluid dynamics simulation, residual stress and distortion, and design of welded structures. He has received numerous honors and awards including the Research Fellowship Award from the Alexander von Humboldt Foundation (1989), the Excellent Research Paper Award from the Korean Welding and Joining Society (1993), the Charles H. Jennings Memorial Award from the American Welding Society (2003), and the Yoshiaki Arata Award from the International Institute of Welding (2014).
The Humboldt Research Award is granted annually to up to 100 academics whose fundamental discoveries, new theories, or insights have had a significant impact on their own discipline and who are expected to continue producing cutting-edge achievements in the future.
The award winners also receive a research grant of 60,000 Euros and are invited to work up to one year with colleagues at research institutions in Germany. Nominations for the award are made only by established academic institutions in Germany.
Professor Na will collaborate with a research team led by Professor Michael Rethmeier at the Berlin-based Federal Institute for Materials Research and Testing (BAM) to conduct research in laser welding and selective laser melting, as well as the mathematical analysis of these manufacturing processes from July 2017 to the end of February 2018.
2016.12.19 View 7076 -
The Antibody That Normalizes Tumor Vessels
Researchers also discover that their antisepsis antibody reduces glioma, lung and breast cancer progression in mice.
A research team at the Center for Vascular Research within the Institute for Basic Science (IBS) discovered that the antisepsis antibody ABTAA (Ang2-Binding and Tie2-Activating Antibody) reduces tumor volume and improves the delivery of anti-cancer drugs. Published in Cancer Cell, this study demonstrates that ABTAA restores the structural and functional integrity of tumor blood vessels in three different tumor models: breast, lungs, and brain.
Blood vessels inside and around an established tumor can be described as a chaotic and dysfunctional labyrinth. While the inner walls of healthy blood vessels are surrounded and supported by endothelial cells and other cells called pericytes, in the established tumor, the endothelial junctions are broken apart and pericytes are also detached. Blood flow into and from the tumor is severely retarded and tumor vessels lacking an intact vessel wall become leaky. This microenvironment causes limited drug delivery to the tumor and leads to inadequate oxygen supply (hypoxia) and even metastasis.
The research team led by Professor Gou-Young Koh at KAIST’s Graduate School of Medical Science and Engineering found that the antibody ABTAA normalizes the tumor vessels and hence, change the whole tumor microenvironment. “We call it normalization of tumor vessels, because it resembles closely the wall architecture of healthy, normal vessels,” explains PARK Jin-Sung, first author of the study. And continues: “Tumor can adapt to hypoxia and get more aggressive, so we tried to prevent this transition by normalizing tumor vessels. ABTAA changes the whole tumor environment, oxygenation status and level of lactate, so that the immune cells and drugs can reach the core regions of the tumor more easily. In this way, we create a favorable ground for tumor treatment.”
In an attempt to generate antibodies targeting the protein Ang2, which is specifically expressed by endothelial cells in stressful conditions like in tumor, the team unexpectedly discovered that ABTAA has a peculiar way of working and a dual function. ABTAA indeed not only blocks Ang2, but also activates Tie2 at the same time. Tie2 is a receptor present on the cell membrane of endothelial cells. ABTAA causes Ang2 to cluster together and to strongly activate Tie2 receptors. “If we activate Tie2, we can efficiently normalize tumor vessels, enhance drug delivery and change the whole microenvironment,” explains KOH Gou Young, Director of the Center for Vascular Research.
Several pharmaceutical companies are developing Ang2-blocking antibodies to cure cancer. However, even if these antibodies significantly inhibit tumor progression, they do not stop tumor hypoxia. Moreover, most of the anti-cancer drugs target the tumor at its early stage, when tumors are still hard to diagnose. ABTAA, instead, works with tumors that are already rooted: “When the tumor is established, hypoxia is the main driver of tumor progression. So, if we eliminate hypoxia, we make the tumor milder, by reducing its progression and metastasis,” comments Koh.
Figure: Schematic drawing of a blood vessel around tumors before and after treatment with ABTAA. The picture above shows a typical tumor vasculature characterized by damaged walls, red blood cells leakage and detached pericytes. Activating Tie2 on endothelial cells with the antibody ABTAA restores the normal vessel architecture: endothelial and pericytes on the vessel walls are stabilized, the delivery of blood is improved, and the anticancer drugs are more likely to reach the tumor core.
The researchers tested ABTAA in mice with three different types of tumors that show high levels of Ang2: glioma (a type of a brain tumor), lung carcinoma, and breast cancer. They also compared the effect of ABTAA with ABA, another antibody that blocks Ang2 but misses the Tie2 activating properties. In all three cases, ABTAA was superior to ABA in inducing tumor vessel normalization, which led to a better delivery of the anti-cancer drugs into the tumor core region.
Glioma is one of the so-called intractable diseases, because of its poor prognosis and treatment. Professor Koh’s team found that the glioma volume was reduced 39% by ABTAA and 17% by ABA. ABTAA profoundly reduced vascular leakage and edema formation in glioma through promoting vascular tightening. Moreover, when ABTAA was administered together with the chemotherapeutic drug temozolomide (TMZ), the tumor volume reduces further (76% by ABTAA+TMZ, 51% by ABA+TMZ, and 36% by TMZ).
In the Lewis Lung Carcinoma (LLC) tumor model, the team administered ABTAA together with a chemotherapeutic drug called cisplatin (Cpt) and observed a greater suppression of tumor growth (52%) compared with the controls and increased overall survival. Moreover, ABTAA+Cpt led to a marked increase in necrotic area within tumors.
Finally, in a spontaneous breast cancer model, ABTAA delayed tumor growth and enhanced the anti-tumor effect of Cpt.
Courtesy of the Institute for Basic Sciences (IBS)
Figure: The antibody ABTAA alone and in combination with other anti-cancer drugs have a beneficial effect in reducing tumor volume. ABTAA was tested in mice with brain tumor (glioma), lung or breast cancer. The image shows the improvements: reduction in glioma tumor size, reduction in metastatic colonies in lung tumor and decrease in necrotic regions in breast tumor.
In the future, the team would like to further understand the underlying relationship between faulty blood vessels and diseases. “We would like to apply this antibody to an organ that is rich in blood vessels, that is the eye, and see if this antibody can be useful to treat eye diseases such as age-related macular degeneration and diabetic retinopathy,” concludes Koh.
Professor Gou-Young Koh (left) and Jin-Sung Park (right)
2016.12.16 View 8233 -
Professor Ih Reappointed as Vice President of the ICA
Professor Jeong-Guon Ih of the Mechanical Engineering Department at KAIST has been re-elected as the Vice President of the International Commission for Acoustics (ICA). His second term of office is from October 16, 2016 to September 30, 2019.
Professor Ih, the first Korean who was selected to a senior position on the ICA management board, took over his current post in 2015 when the vice president at the time passed away in the middle of his term.
During his stint, Professor Ih played a key role in planning the ICA’s triennial gathering, the International Congress on Acoustics, in Gyeongju, Korea, scheduled for October 24-28, 2022. He will also serve as the general chair for the conference.
The International Congress on Acoustics is the largest professional meeting in the field of acoustics. It provides a venue to meet, discuss, and exchange ideas covering all aspects of acoustics including an extensive technical exhibition that highlights the latest advances in acoustical products such as materials, systems, and equipment.
Acoustics has grown to become an important element in the Information Age in the areas of automation, machine learning, and virtual reality. Hosting the Congress will support Korea’s goal to lead acoustic research and development on the global stage.
Professor Ih said, “Serving international academic organizations offers great opportunities to learn global trends and to collaborate with various research institutions, universities, and industries worldwide. I hope my service will inspire many young Korean researchers to pursue their careers in this field.”
Professor Ih is also a member of eight eminent international academic societies such as the Audio Engineering Society, the International Congress on Ultrasonics, and the International Institute of Noise Control Engineering.
The ICA was founded in 1951 as a subcommittee of the International Union of Pure and Applied Physics (IUPAP), and it consists of 46 member states and four observer nations. It promotes international development and collaboration in all fields of acoustics including research, development, education, and standardization.
2016.12.16 View 5983 -
KAIST's Board of Trustees Reappoints Dr. Jang-Moo Lee as Chairman
Dr. Jang-Moo Lee, the incumbent Chairman of the KAIST Board of Trustees, has been re-elected to head the office. His term will begin from the date of approval by the Minister of Science, ICT and Future Planning of Korea and will last for three years.
Dr. Lee received his undergraduate and master’s degrees in mechanical engineering from Seoul National University. He later earned his doctoral degree in mechanical engineering from Iowa State University in the United States.
Joined the faculty of his alma mater in 1976, Dr. Lee held various posts within the university including the dean of the engineering college. He served as the president of the Association of Korean Engineering Colleges, the founding chairman of the Korea Evaluation Institute of Industrial Technology, the president of the Korean Society of Mechanical Engineers, the 24th president of Seoul National University, and the 13th president of the Korean Council for University Education. He now serves as the president of the National Science and Technology Council of Korea and the chairman of Climate Change Center’s Board of Directors.
Dr. Lee has received numerous honors and awards, among others, the Academic Award of the Korean Society of Mechanical Engineers (1985), the Order of Science and Technology Merit from the Korean government (2005), the National Academy of Sciences Award (2005), and the Order of Service Merit in Blue Stripes (2010) from the Korean government. He was also selected as the Alma Mater Proud from Kyunggi High School in 2011.
2016.12.15 View 3717 -
Professor Hyun Chung Claims the Elmer L. Hann Award 2016
Professor Hyun Chung of KAIST’s Mechanical Engineering Department received the Elmer L. Hann Award 2016 at the SNAME Maritime Convention (SMC) that took place November 1-5 in Seattle, Washington, in the United States.
Held annually, the SMC is the largest academic gathering for researchers and professionals in maritime and ocean engineering, and it is hosted by the Society of Naval Architects and Marine Engineers (SNAME).
With more than 6,000 members around the world in 85 countries, SNAME is an internationally-recognized, non-profit, professional society of individual members serving the maritime and offshore industries and their suppliers. It strives to advance the art, science, and practice of naval architecture, marine engineering, ocean engineering, and other marine-related professions through the exchange of knowledge and ideas, as well as the promotion of R&D, and education.
Every year, SNAME selects three research papers that are either published in its academic journal or presented at its sponsored conferences and awards them, respectively. One of the three awards is the Elmer L. Hann Award.
This year, the Society announced Professor Chung’s paper as the Elmer L. Hann Award winner. His paper, entitled “Tolerance Analysis and Diagnosis Model of Compliant Block Assembly Considering Welding Deformation,” was presented at the World Maritime Technology Conference held November 3-7, 2015 in Providence, Rhode Island, USA.
Analysis, management, and diagnostics of tolerance are important factors in the production of ocean structures. In the paper, Professor Chung’s team proposed a simplified tolerance analysis and diagnosis model including the effects of welding distortion for accuracy control in ship block assembly, thereby improving the production process.
Professor Chung said, “This is indeed a wonderful award for our team. From early this year, with support from the U.S. Office of Naval Research, we have collaborated with the University of Michigan, the Massachusetts Institute of Technology, Ohio State University, and the Edison Welding Institute to study this topic more deeply. We will keep up the good work to make meaningful progress.”
2016.12.10 View 7345 -
Mechanical Engineering Building on Campus Refurbished
KAIST’s Mechanical Engineering Department has finished the project to remodel its buildings and hosted an opening ceremony on December 12, 2016, which was attended by the university’s senior management and guests including President Steve Kang and Choong-Hwan Ahn, Architecture Policy Officer at the Ministry of Land, Infrastructure and Transport of Korea (MLIT).
With an investment of approximately USD 10 million, the old buildings (each consisting of seven floors and one basement) were transformed into smart, green buildings. Among the upgrades were the establishment of LED lighting systems, the replacement of the exterior walls with insulated materials, and the installation of double-glazed windows, all resulting in the improvement of the buildings’ energy efficiency. Previously, offices and lecture halls in the buildings had individual cooling and heating systems, which consumed a great deal of energy, but they were replaced with a centralized smart energy control system that monitors the operation status as well as energy consumption in real time.
With these new improvements, the Department was able to slash its energy consumption by 32%, for which it received Green Building Conversion Certification from MLIT. The ministry issues the certification to buildings that reduce their energy consumption by over 20% as a result of infrastructure upgrades. Beginning with the Mechanical Engineering buildings, KAIST will work on obtaining this certification for all of its buildings that are either under renovation or construction.
President Kang said, “We are pleased to offer our students a comfortable environment for study and research and will continue improving outdated facilities and infrastructure to make the campus safer and nicer.”
Picture 1: Ribbon-cutting ceremony for the refurbished Mechanical Engineering buildings on campus
Picture 2: Mechanical engineering buildings
2016.12.09 View 6103 -
A KAIST Team Wins the Chem-E-Car Competition 2016
A KAIST team consisted of four students from the Department of Chemical and Biomolecular Engineering won the Chem-E-Car Competition 2016, which took place on November 13 at the Union Square in San Francisco. The students who participated were Young-Hyun Cha, Jin-Sol Shin, Dae-Seok Oh, and Wan-Tae Kim. Their adviser was Professor Doh Chang Lee of the same department.
Established in 1999, the Chem-E-Car is an annual worldwide college competition for students majoring in chemical engineering. The American Institute of Chemical Engineers (AIChE), founded in 1908, is the world’s leading organization for chemical engineering professionals with more than 50,000 members from over 100 countries and hosts this competition every year.
A total of 41 university teams including Carnegie Mellon University and Purdue University participated in this year’s competition.
KAIST students competed in the event for the first time in 2014 and reached the rank of 28. In 2015, the students placed 16th, and finally, took the first place in last month’s competition, followed by the Georgia Institute of Technology.
In the competition, students must design small-scale (20x30x40 cm) automobiles that operate chemically, as well as describe their research and drive their car a fixed distance down a wedge-shaped course to demonstrate the car’s capabilities. In addition to driving a specified distance (15-30 meters), the car must hold a payload of 0-500 mL of water.
The organizers tell participants the exact distance and amount of payloads one hour before the competition begins. Winners are chosen based on their finishing time and how close their car reaches the finish line. Thus, students must show sophisticated coordination of chemical reactions to win.
The KAIST team designed their car to have a stable power output using a Vanadium redox flow battery developed by Professor Hee Tak Kim of Chemical and Biomolecular Engineering. They employed iodine clock reactions to induce quick and precise chemical reactions to control their car.
KAIST’s car finished with the best run coming within 11 cm of the target line; Georgia Tech’s car reached the finish line by 13 cm and New Jersey Institute of Technology’s car by 14 cm.
Young-Hyun Cha, one of the four students, said, “When we first designed our car, we had to deal with many issues such as stalls or connection errors. We kept working on fixing these problems through trial and error, which eventually led us to success.”
For a news article on KAIST’s win at 2016 Chemi-E-Car Competition by AIChE, see the link below:
http://www.aiche.org/chenected/2016/11/koreas-kaist-wins-1st-place-2016-chem-e-car-competition-photos
2016.12.08 View 9658 -
Professor Young Jae Jang Receives the Grant Award from Mathworks
Professor Young Jae Jang of KAIST’s Industrial and Systems Engineering Department won the Grant Award from Mathworks, Inc., an American developer of mathematical computing software. Headquartered in Massachusetts in the United States, Mathworks has been known for its MATLAB software that is used by many engineers and scientists around the world for algorithm development, data analysis, visualization, and numeric computation.
Winners of the Grant Award are selected from proposals submitted by educational institutions in 18 different countries based on their innovative lab curricula and future potential for innovation and creativity.
Award winners receive a cash grant of up to USD 40,000 as well as various other forms of support including software and technical guidance for creating a course.
Professor Jang has researched combining the concept of industrial engineering education with Lego principles since 2014. He developed Lego-based experimental equipment and utilized it to teach students about difficult ideas, for example, big data and manufacturing technologies needed for Industry 4.0, such as automation, cyber-physical systems, the Internet of Things, and cloud computing. He created an innovative teaching environment where students learn engineering concepts and then conduct experiments on their own to understand the new paradigm of industrial systems.
Lego-based education allows students to personalize their learning process, shifting lecture-centered approaches toward learner-oriented approaches. Students apply theories to operate tools and equipment made with Lego, identify problems, and find solutions. In such processes, they can understand the content of their study more easily and efficiently and become more motivated.
Professor Jang’s research has attracted a great deal of interest overseas, and he is frequently invited to international conferences as a keynote speaker.
Picture: Lego-based Learning Model of Experiment Equipment Developed by Professor Young Jae Jang
2016.12.08 View 6131 -
Mobile Software Platform Research Center Recognized by the MSIP
The Mobile Software Platform Research Center (MSPRC) at KAIST received an award from the Minister of Science, ICT and Future Planning of Korea on November 29, 2016, at Coex in Seoul. The award was presented at the Conference of Software R&D Annual Report 2016 hosted by the Ministry of Science, ICT and Future Planning (MISP) and the Institute for Information and Communications Technology Promotion (IITP).
The research center developed user experience (UX)-oriented mobile software platforms that support the invention of next-generation UX service technologies. The center has filed 37 patents and registered 15 technologies. Its researchers received ten Best Paper Awards and published a total of 133 papers in Korean and international journals.
Research teams at MSPRC expect that their software platforms will offer training programs for software engineers and new UX services. They also said that their extensive event processing platforms would reduce energy consumption on mobile devices.
Professor Seungryoul Maeng of the School of Computing, the Director of MSPRC, said, “This is a great honor for us. I am greatly thankful for the teamwork of participating departments--Computer Science, Industrial Design, and Industrial and Systems Engineering. We will continue to introduce our research outcomes and to work towards commercializing these results.”
Members of the Mobile Software Platform Research Center, KAIST
2016.12.07 View 6449 -
Professor Kwon to Represent the Asia-Pacific Region of the IEEE RAS
Professor Dong-Soon Kwon of the Mechanical Engineering Department at KAIST has been reappointed to the Administrative Committee of the Institute of Electrical and Electronics Engineers (IEEE) Robotics and Automation Society (IEEE RAS). Beginning January 1, 2017, he will serve his second three-year term, which will end in 2019. In 2014, he was the first Korean appointed to the committee, representing the Asia-Pacific community of the IEEE Society.
Professor Kwon said, “I feel thankful but, at the same time, it is a great responsibility to serve the Asian research community within the Society. I hope I can contribute to the development of robotics engineering in the region and in Korea as well.”
Consisted of 18 elected members, the administrative committee manages the major activities of IEEE RAS including hosting its annual flagship meeting, the International Conference on Robotics and Automation.
The IEEE RAS fosters the advancement in the theory and practice of robotics and automation engineering and facilitates the exchange of scientific and technological knowledge that supports the maintenance of high professional standards among its members.
2016.12.06 View 8033 -
Mystery of Biological Plastic Synthesis Machinery Unveiled
Plastics and other polymers are used every day. These polymers are mostly made from fossil resources by refining petrochemicals. On the other hand, many microorganisms naturally synthesize polyesters known as polyhydroxyalkanoates (PHAs) as distinct granules inside cells.
PHAs are a family of microbial polyesters that have attracted much attention as biodegradable and biocompatible plastics and elastomers that can substitute petrochemical counterparts. There have been numerous papers and patents on gene cloning and metabolic engineering of PHA biosynthetic machineries, biochemical studies, and production of PHAs; simple Google search with “polyhydroxyalkanoates” yielded returns of 223,000 document pages. PHAs have always been considered amazing examples of biological polymer synthesis. It is astounding to see PHAs of 500 kDa to sometimes as high as 10,000 kDa can be synthesized in vivo by PHA synthase, the key polymerizing enzyme in PHA biosynthesis. They have attracted great interest in determining the crystal structure of PHA synthase over the last 30 years, but unfortunately without success. Thus, the characteristics and molecular mechanisms of PHA synthase were under a dark veil.
In two papers published back-to-back in Biotechnology Journal online on November 30, 2016, a Korean research team led by Professor Kyung-Jin Kim at Kyungpook National University and Distinguished Professor Sang Yup Lee at the Korea Advanced Institute of Science and Technology (KAIST) described the crystal structure of PHA synthase from Ralstonia eutropha, the best studied bacterium for PHA production, and reported the structural basis for the detailed molecular mechanisms of PHA biosynthesis. The crystal structure has been deposited to Protein Data Bank in February 2016. After deciphering the crystal structure of the catalytic domain of PHA synthase, in addition to other structural studies on whole enzyme and related proteins, the research team also performed experiments to elucidate the mechanisms of the enzyme reaction, validating detailed structures, enzyme engineering, and also N-terminal domain studies among others.
Through several biochemical studies based on crystal structure, the authors show that PHA synthase exists as a dimer and is divided into two distinct domains, the N-terminal domain (RePhaC1ND) and the C-terminal domain (RePhaC1CD). The RePhaC1CD catalyzes the polymerization reaction via a non-processive ping-pong mechanism using a Cys-His-Asp catalytic triad. The two catalytic sites of the RePhaC1CD dimer are positioned 33.4 Å apart, suggesting that the polymerization reaction occurs independently at each site. This study also presents the structure-based mechanisms for substrate specificities of various PHA synthases from different classes.
Professor Sang Yup Lee, who has worked on this topic for more than 20 years, said,
“The results and information presented in these two papers have long been awaited not only in the PHA community, but also metabolic engineering, bacteriology/microbiology, and in general biological sciences communities. The structural information on PHA synthase together with the recently deciphered reaction mechanisms will be valuable for understanding the detailed mechanisms of biosynthesizing this important energy/redox storage material, and also for the rational engineering of PHA synthases to produce designer bioplastics from various monomers more efficiently.”
Indeed, these two papers published in Biotechnology Journal finally reveal the 30-year mystery of machinery of biological polyester synthesis, and will serve as the essential compass in creating designer and more efficient bioplastic machineries.
References:
Jieun Kim, Yeo-Jin Kim, So Young Choi, Sang Yup Lee and Kyung-Jin Kim. “Crystal structure of Ralstonia eutropha polyhydroxyalkanoate synthase C-terminal domain and reaction mechanisms” Biotechnology Journal DOI: 10.1002/biot.201600648
http://onlinelibrary.wiley.com/doi/10.1002/biot.201600648/abstract
Yeo-Jin Kim, So Young Choi, Jieun Kim, Kyeong Sik Jin, Sang Yup Lee and Kyung-Jin Kim. “Structure and function of the N-terminal domain of Ralstonia eutropha polyhydroxyalkanoate synthase, and the proposed structure and mechanisms of the whole enzyme” Biotechnology Journal DOI: 10.1002/biot.201600649
http://onlinelibrary.wiley.com/doi/10.1002/biot.201600649/abstract
2016.12.02 View 9031 -
Making Graphene Using Laser-induced Phase Separation
IBS & KAIST researchers clarify how laser annealing technology can lead to the production of ultrathin nanomaterials
All our smart phones have shiny flat AMOLED (active-matrix organic light-emitting diode) displays. Behind each single pixel of these displays hides at least two silicon transistors which are mass-manufactured using laser annealing technology. While the traditional methods to make the transistors use temperature above 1,000°C, the laser technique reaches the same results at low temperatures even on plastic substrates (melting temperature below 300°C). Interestingly, a similar procedure can be used to generate crystals of graphene. Graphene is a strong and thin nano-material made of carbon, its electric and heat-conductive properties have attracted the attention of scientists worldwide.
Professor Keon Jae Lee of the Materials Science and Engineering Department at KAIST and his research group at the Center for Multidimensional Carbon Materials within the Institute for Basic Science (IBS), as well as Professor Sung-Yool Choi of the Electrical Engineering School at KAIST and his research team discovered graphene synthesis mechanism using laser-induced solid-state phase separation of single-crystal silicon carbide (SiC). This study, available in Nature Communications, clarifies how this laser technology can separate a complex compound (SiC) into its ultrathin elements of carbon and silicon.
Although several fundamental studies presented the effect of excimer lasers in transforming elemental materials like silicon, the laser interaction with more complex compounds like SiC has rarely been studied due to the complexity of compound phase transition and ultra-short processing time.
With high resolution microscope images and molecular dynamic simulations, scientists found that a single-pulse irradiation of xenon chloride excimer laser of 30 nanoseconds melts SiC, leading to the separation of a liquid SiC layer, a disordered carbon layer with graphitic domains (about 2.5 nm thick) on top surface and a polycrystalline silicon layer (about 5 nm) below carbon layer. Giving additional pulses causes the sublimation of the separated silicon, while the disordered carbon layer is transformed into a multilayer graphene.
"This research shows that the laser material interaction technology can be a powerful tool for the next generation of two dimensional nanomaterials," said Professor Lee.
Professor Choi added: "Using laser-induced phase separation of complex compounds, new types of two dimensional materials can be synthesized in the future."
High-resolution transmission electron microscopy shows that after just one laser pulse of 30 nanoseconds, the silicon carbide (SiC) substrate is melted and separates into a carbon and a silicon layer. More pulses cause the carbon layer to organize into graphene and the silicon to leave as gas.
Molecular dynamics simulates the graphene formation mechanism. The carbon layer on the top forms because the laser-induced liquid SiC (SiC (l)) is unstable.
(Press Release by Courtesy of the Institute for Basic Science (IBS))
2016.12.01 View 9969