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KAIST's classes now available to take from all around the world
Signed a partnership agreement with Coursera to provide millions of people with online courses in science and technology.
The Korea Advanced Institute of Science and Technology (KAIST), a world-leading research university focusing on science, engineering and technology, joined a new, online platform for open access that serves the needs of Korean and global learners.
KAIST and Coursera, the world"s largest provider of massive open online courses (MOOCs), agreed on October 14th, 2013 to partner for the provision of internet-based open learning, through which the university expects to reinforce its current education initiative, Education 3.0.Steve Kang, president of KAIST, was upbeat about the partnership."We know the benefits and importance of online education that will significantly impact the landscape of today"s higher education. Hopefully, our partnership with Coursera will expand our initiative to continuously provide quality education globally."
With its network of 107 prestigious partner universities and public institutions worldwide, Coursera offers 482 free online courses across a wide field of humanities, science, engineering, and business to 5 million students around the globe.
KAIST will be able to utilize top-notch online courses and lecture contents available on the company"s website. The university can also supply its online courses to the global community, allowing the faculty"s top quality lectures to reach hundreds and thousands of students and adult learners throughout the world.Incorporating advanced information and communications technology, KAIST has implemented a new, smart education program, Education 3.0, since 2012 to effectively meet the growing demands of creating a better and more interactive learning and teaching environment for students and faculty. Under Education 3.0, students study online and meet in groups with a professor for discussions and problem solving.
Tae-Eog Lee, Director of the Center for Excellence in Learning & Teaching at KAIST, said:"We received a phenomenal response from students and professors to the courses made available under Education 3.0. For this year alone, we are offering 60 courses, such classes as calculus, general biology, basic programming, design and communication, bioengineering fundamentals, and logic and artificial intelligence."
Professor Lee added:"It has turned out that our education initiative is not only useful to our students but also quite popular among learners outside the university and Korea. It"s a great thing that KAIST can contribute to the world"s concerted efforts to provide equal opportunities for learning. At the same time, we look forward to seeing the benefits of MOOC-based content being used in our classrooms."
Founded in 2012 by two eminent Stanford University professors, Coursera has held a strong lead in MOOCs. Unlike the traditional online education model, open courseware (OCW), designed for simply sharing lecture materials including videos, slides, and data through the internet, MOOCs develop and evaluate courses, lecture contents, and delivery quality to meet high academic standards—In order to earn credits, subscribers (universities and students) are required to submit course registration, specification, and description; student attendance roster; homework and assignments; and assessment.
Daphne Koller, co-founder of Coursera, commented on the partnership agreement with KAIST:"We are honored to have so many brilliant minds working together to expand educational opportunities globally. To be able to offer courses from professors at the forefront of their fields to millions of people is truly remarkable, and our students remind us daily of the value of spreading this knowledge globally."
Among the partner universities and institutions are Stanford University, California Institute of Technology, Columbia University, École Polytechnique Fédérale de Lausanne, Technion-Israel Institute of Technology, the National University of Singapore, the University of Tokyo, the World Bank, and Shanghai Jiao Tong University.
President Steve Kang (in the left) singed a partnership agreement with Dr. Daphne Koller (in the right), president and CEO of Coursera.
2013.11.04 View 10233 -
KAIST Hosted the 6th International Presidential Forum on Global Research Universities
More than 120 global leaders from higher education, private and public sectors, to discuss the promotion of economic growth through knowledge creation and entrepreneurship
The Korea Advanced Institute of Science and Technology (KAIST) held the 6th International Presidential Forum on Global Research Universities (IPFGRU) on October 15th at the Westin Chosun Hotel in Seoul, Republic of Korea.
About 64 presidents and vice presidents from 57 research universities in 28 nations attended for a presentation and panel discussion on the topic of “The Role and Responsibility of Research Universities: Knowledge Creation, Technology Transfer, and Entrepreneurship.”Annually held, the forum is organized to promote excellence and innovation in higher education and provide a place for discussion among prominent research university leaders and key policy-makers in the private and public sectors from across the world.Among the notable universities attending the 2013 forum were the University of California, Irvine, the École Polytechnique Fédérale de Lausanne, Technische Universität Berlin, Technion-Israel Institute of Technology, Tokyo Institute of Technology, Rice University, the University of Waterloo, and Massachusetts Institute of Technology (MIT). Government officials as well as representatives from business and industry such as Samsung Electronics, Korea Telecom, and Elsevier also joined the event.
The forum was proceeded with three separate sessions: Enabling Knowledge Creation, Entrepreneurship & University-Based Technology Transfer, and Higher Education & Strategic Knowledge Creation: Specialization & Performance, through which speakers and panelists examined how universities have played a role in knowledge creation and technology transfer, and ultimately how they have contributed to the development of national economies.
Keynote speakers were Michael Drake, chancellor of UC Irvine, and Jörg Steinbach, president of Technische Universität Berlin. Forum participants shared their experiences and insights in starting up knowledge- and technolgy-based new businesses.
Steve Kang, president of KAIST, talked about the purpose of the 2013 IPFGRU:
“In the face of an ever-changing economic climate driven by shifts in technological advancement, demographic trends, and global integration, the role of research universities is becoming ever more significant in achieving sustainable economic growth. This forum will help participants from around the world to define the choices ahead as universities seek the most productive and beneficial models for cooperation with industry, venture startups, and government.”For the 2013 IPFGRU, Ministry of Science, ICT, and Future Planning, ROK, Saudi Aramco, Samsung Heavy Industries, S-Oil, Elsevier, Thomson Reuters, and the Korea Economic Daily were forum sponsors.
2013.11.04 View 10992 -
A powerful strategy for developing microbial cell factories by employing synthetic small RNAs
The current systems for the production of chemicals, fuels and materials heavily rely on the use of fossil resources. Due to the increasing concerns on climate change and other environmental problems, however, there has been much interest in developing biorefineries for the production of such chemicals, fuels and materials from renewable resources. For the biorefineries to be competitive with the traditional fossil resource-based refineries, development of high performance microorganisms is the most important as it will affect the overall economics of the process most significantly. Metabolic engineering, which can be defined as purposeful modification of cellular metabolic and regulatory networks with an aim to improve the production of a desired product, has been successfully employed to improve the performance of the cell. However, it is not trivial to engineer the cellular metabolism and regulatory circuits in the cell due to their high complexity.
In metabolic engineering, it is important to find the genes that need to be amplified and attenuated in order to increase the product formation rate while minimizing the production of undesirable byproducts. Gene knock-out experiments are often performed to delete those metabolic fluxes that will consequently result in the increase of the desired product formation. However, gene knock-out experiments require much effort and time to perform, and are difficult to do for a large number of genes. Furthermore, the gene knock-out experiments performed in one strain cannot be transferred to another organism and thus the whole experimental process has to be repeated. This is a big problem in developing a high performance microbial cell factory because it is required to find the best platform strain among many different strains. Therefore, researchers have been eager to develop a strategy that allows rapid identification of multiple genes to be attenuated in multiple strains at the same time.
A Korean research team led by Distinguished Professor Sang Yup Lee at the Department of Chemical and Biomolecular Engineering from the Korea Advanced Institute of Science and Technology (KAIST) reported the development of a strategy for efficiently developing microbial cell factories by employing synthetic small RNAs (sRNAs). They first reported the development of such system in Nature Biotechnology last February. This strategy of employing synthetic sRNAs in metabolic engineering has been receiving great interest worldwide as it allows easy, rapid, high-throughput, tunable, and un-doable knock-down of multiple genes in multiple strains at the same time. The research team published a paper online on August 8 as a cover page (September issue) in Nature Protocols, describing the detailed strategy and protocol to employ synthetic sRNAs for metabolic engineering.
In this paper, researchers described the detailed step-by-step protocol for synthetic sRNA-based gene expression control, including the sRNA design principles. Tailor-made synthetic sRNAs can be easily manipulated by using conventional gene cloning method. The use of synthetic sRNAs for gene expression regulation provides several advantages such as portability, conditionality, and tunability in high-throughput experiments. Plasmid-based synthetic sRNA expression system does not leave any scar on the chromosome, and can be easily transferred to many other host strains to be examined. Thus, the construction of libraries and examination of different host strains are much easier than the conventional hard-coded gene manipulation systems. Also, the expression of genes can be conditionally repressed by controlling the production of synthetic sRNAs. Synthetic sRNAs possessing different repression efficiencies make it possible to finely tune the gene expression levels as well. Furthermore, synthetic sRNAs allow knock-down of the expression of essential genes, which was not possible by conventional gene knock-out experiments.
Synthetic sRNAs can be utilized for diverse experiments where gene expression regulation is needed. One of promising applications is high-throughput screening of the target genes to be manipulated and multiple strains simultaneously to enhance the production of chemicals and materials of interest. Such simultaneous optimization of gene targets and strains has been one of the big challenges in metabolic engineering. Another application is to fine tune the expression of the screened genes for flux optimization, which would enhance chemical production further by balancing the flux between biomass formation and target chemical production. Synthetic sRNAs can also be applied to finely regulating genetic interactions in a circuit or network, which is essential in synthetic biology. Once a sRNA scaffold-harboring plasmid is constructed, tailor-made, synthetic sRNAs can be made within 3-4 days, followed by the desired application experiments.
Dr. Eytan Zlotorynski, an editor at Nature Protocols, said "This paper describes the detailed protocol for the design and applications of synthetic sRNA. The method, which has many advantages, is likely to become common practice, and prove useful for metabolic engineering and synthetic biology studies."
This paper published in Nature Protocols will be useful for all researchers in academia and industry who are interested in the use of synthetic sRNAs for fundamental and applied biological and biotechnological studies.
This work was supported by the Technology Development Program to Solve Climate Changes on Systems Metabolic Engineering for Biorefineries (NRF-2012-C1AAA001-2012M1A2A2026556) and the Intelligent Synthetic Biology Center through the Global Frontier Project (2011-0031963) of the Ministry of Science, ICT and Future Planning through the National Research Foundation of Korea.
2013.10.31 View 10118 -
First Prize in the 2013 International Military Science and Technology Contest
Professor James R. Morrison and his students of the Industrial and Systems Engineering Department at KAIST were awarded the first prize in the 2013 International Military Science and Technology Contest organized by the Defense Acquisition Program Administration held in COEX from July 11 to 14.
The research group, Byungduk Song (Ph.D candidate), Jonghoe Kim (Ph.D candidate), Hyolin Park (MS candidate) and Professor James R. Morrison, received the first prize with their paper entitled “Automated and persistent UAV system for a complementary method for border patrol and target tracking.”
The Defense Acquisition Program Administration is the host of the annual contest which aims to contribute to the future of the defense industry and to expand technology exchange between private institutes and the military through the coordination of defense technology and advanced technology from industrial and educational cooperation.Professor Morrison’s team received the honor of the first-place prize out of 56 competitors from within Korea and 7 from overseas in the field of Synthetic New Technology/Academic Thesis.
2013.10.31 View 9533 -
Core Technology for Lithium Air Secondary Battery Developed
KAIST-Kyonggi University joint research team developed composite catalyst out of nano fiber and graphene
Five times improvement in capacity compared to lithium-ion secondary battery, driving 800 km at maximum
The core technology for lithium air secondary battery, the next generation high capacity battery, has been developed.
A research team formed by KAIST Department of Materials Science’s Professors Il-Doo Kim and Seokwoo Jeon, and Kyonggi University Department of Materials Science’s Professor Yong-Joon Park has created a lithium air secondary battery, with five times greater storage than the lithium-ion secondary battery, by developing a nano fiber-graphene composite catalyst. The research results are published in the August 8th online edition of Nano Letters.
A cathode of a lithium-ion battery consists of graphite and an anode of the battery consists of a lithium transition metal oxide. Lithium-ion batteries are widely used in mobile phones and laptops. However, lithium-ion batteries cannot support electric vehicles, providing energy for only 160 kilometers on one full charge. The lithium air secondary battery just developed by the research team uses lithium on the cathode and oxygen on the anode. It is earning a popular acknowledgement among the next generation secondary battery research community for having lightweight mass and high energy density.
However, lithium-ion batteries remain difficult to commercialize because of their short lifespan. Lithium and oxygen meet up to form lithium oxide (Li2O2) at discharge, and decompose again at charge. In a traditional lithium air battery, this cycle does not occur smoothly and results in high resistance, thereby reducing the lifespan of the battery. It is thus essential to develop high efficiency catalyst that facilitates the formation and decomposition of lithium oxides.
The research team used electric radiation to develop a nano composite catalyst by mixing cobalt oxide nano fiber and graphene. The performance of the battery has been maximized by settling nonoxidative graphene, which has high specific surface area and electrical conductivity, on catalyst active cobalt oxide nano fiber. Applying the nano composite catalyst on both poles of the lithium air battery resulted in an improved lifespan of over 80 recharge cycles with capacity greater than 100mAh/g, five times greater than a lithium ion battery. The newly discovered charge-discharge property is the highest among the reported performances of the lithium air battery so far.
The lithium air battery is cheap to make, as the main materials are metal oxide and graphene. “There are yet more issues to resolve such as stability, but we will collaborate with other organizations to open up the era of electronic vehicles,” said Professor Il-Doo Kim. “We hope to contribute to vitalizing the fields of next generation lithium air battery by leading nanocatalyst synthesis technology, one of the core materials in the fields of secondary battery,” Professor Kim spoke of his aspiration.
The graduate students participated in the research are Won-Hee Ryu, a postdoctorate at KAIST Department of Materials Science, Sungho Song, a PhD candidate at KAIST Department of Materials Science, and Taek-Han Yoon, a graduate student at Kyonggi University.
Picture I: Schematic Diagram of Lithium Air Battery Made of Nano Composite Catalysts
Picture II: Images of Cobalt Oxide Nano Fibers and Graphene Nano Composite Catalysts
Picture III: Images of Manufacturing Process of Cobalt Oxide Nano Fibers and Graphene Nano Composite Catalysts for Lithium Air Battery
2013.10.18 View 12383 -
Therapy developed to induce Angiogenesis of Retina
- Junyeop Lee, Graduate School of Medical Sciences and Engineering
- Research results expected to be applied for treatment of diabetic retinopathy
A major clue to treatment of retinovascular disease, which causes blindness, has been found. The key to protection of the retinal nerve is the angiogenic protein that promotes healthy retinal vessel growth around the retina, which usually does not receive blood supply readily. This research offers a beginning to the possible improvement of therapy for diabetic retinopathy1 and retinopathy of prematurity2. Also important to the research is the fact that the ophthalmology specialist researcher, currently undergoing professional training, provided the results.
KAIST Graduate School of Medical Sciences and Engineering’s Junyeop Lee is the opthalmology specialist, who carried out the research under supervision by academic advisers Gyuyeong Go and Wookjun Yoo. The Ministry of Science, ICT and Future Planning as well as the National Research Foundation of Korea have funded his research. The research results have been published as a cover paper on ‘Science Translational Medicine’ on 18th August. This journal is a sister publication of Science, which is prestigious in the field of translational medicine that ties the basic science with clinical medicine. (Thesis title: Angiopoietin-1 Guides Directional Angiogenesis Through Integrin αvβ5 Signaling for Recovery of Ischemic Retinopathy)
The traditional treatment of diabetic retinopathy includes laser photocoagulation to destroy the retinal tissues or antibody therapeutics, which prevents vessel proliferation and blood leaking. The advantage of antibody therapeutics3 is that it retains the retinal nerves, however, it is not the fundamental solution but merely a temporary one, which requires repeated treatments.
The research team identified that Angiopoietin-14 protein, known as essential for growth and stabilization of vessels, also plays an important role in retinal vessel growth. The protein protects the retinal nerves, as well as provides improvement for retinal ischemia5 that is the root cause of vision loss due to retinal hemorrhages. It is expected to become a key to finding fundamental treatment method – by providing sufficient blood supply to the retina, thereby preserving the retinal nerve functions.
The results show that administration of Angiopoietin-1 to retinopathy mouse model promotes growth of healthy vessel growth, further preventing abnormal vessel growth, retinal hemorrhage and vision loss due to retinal ischemia.
Junyeop Lee said, “This research has identified that Angiopoietin-1 is an important factor in retinal vessel generation and stabilization. The paradigm will shift from traditional treatment method, which prevents vessel growth, to a new method that generates healthy vessels and strengthens vessel functions.”
1 Diabetic retinopathy: This retinovascular disease is a diabetic complication caused by insufficient blood supply. It is the major causes of blindness in adults.
2 Retinopathy of prematurity: The retinal vascular disease that occurs in premature infants with incomplete retinal vascular development. It is also the most common cause of blindness in children.
3 Antibody Therapeutics: Antibody developed to selectively inhibit abnormal blood vessel growth and leakage. Typical antibody therapeutics is Avastin and Lucentis, which hinder vascular endothelial growth factor (VEGF).
4 Angiopoietin-1: A critical growth factor that induces the production of healthy blood vessels and maintains the stability of the created vessel.
5 Retinal ischemia: State of ailment where retinal tissue blood supply is not sufficient.
Figure 1. Retinopathy mouse models show that, in comparison to the control group, the VEGF-Trap treatment and Angiopoietin-1 (Ang1) treatment groups significantly suppresses the pathological vascular proliferation. In addition, the Ang 1 group show vessel growth toward the central avascular area (region of retinal ischemia), which is not observed in VEGF-Trap treatment.
Figure 2. Reduced retinal ischemia, retinal bleeding and blood vessel normalization by Angiopoietin-1. Retinal ischemic region (arrow) and retinal bleeding significantly reduced in the Angiopoietin-1 (Ang1) treatment model in comparison to control group (left). The newly generated vessels in Ang 1 model are structurally supported by perivascular cells as normal retinal vessels do (right).
2013.10.12 View 11964 -
KAIST to establish Ombudsperson system
KAIST has recently undergone a massive reorganization to achieve a streamlined system and highly efficient administration; and it will now implement the new “Ombudsperson” system to hear the opinions of the members of the university.
On September 9th, President Sungmo Kang held a ceremony to appoint Professors Sang-Young Shin and Hong-Gu Shim as the new “Ombudspersons”.
The previous Shinmungo system raised complaints and recommendations for improvements by members of the university, but this is the first time that KAIST has assigned a direct department for handling such matters.
The newly appointed Ombudspersons will review for the possibility of any unjust, irrational systems, violations of research ethics and such. It is their role to take a neutral stance and advise on the correction and improvement.
The merit of the Ombudsperson system is that diverse opinions can be reflected on the policy. The Ombudsperson guarantees the security of the contents of discussion so that anyone can share his or her opinion without fear of being recorded in documents.
It is expected that the Ombudsperson system will protect the interests of the individuals and thus contribute to making a “happy campus”.
President [Sungmo] Kang has said that the reason establishing the office of the Ombudsperson is “In order for KAIST to take a new leap toward the world, it is crucial to bring the minds of the members together…. Even the smallest voices must be heard to present solutions to make the university where everyone’s happy.”
In 1809, the Swedish Parliament appointed the first “Ombudsperson” to investigate and resolve civil complaints. Now, it is widely used in public institutions, corporations and universities to improve the communication and work efficiency of the members.
The new Ombudsmen: Prof. Sang-Young Shin (left) and Prof. Hong-Gu Shim (right)
2013.09.27 View 11666 -
Jellyfish Exterminator Robot Developed
Formation Control demonstrated by JEROS
- Trial performance successfully completed with three assembly robots -
A team led by KAIST Civil and Environmental Engineering Department’s Professor Hyeon Myeong has just finished testing the cooperative assembly robot for jellyfish population control, named JEROS, in the field.
The rising number of accidents and financial losses by fishing industry, estimated at 300 billion won per year, caused by the recent swarm of jellyfish in coastal waters has been a major problem for many years. The research team led by Prof. Hyeon Myeong began developing an unmanned automated system capable of eradicating jellyfishin in 2009, and has since completed field-tests last year with success.
This year, JEROS’s performance and speed has been improved with the ability to work in formation as a cooperative group to efficiently exterminate jellyfish.
An unmanned aquatic robot JEROS with a mountable grinding part is buoyed by two cylindrical bodies that utilizes propulsion motors to move forward and reverse, as well as rotate 360 degrees. Furthermore, GIS (geographic information system)-based map data is used to specify the region for jellyfish extermination, which automatically calculates the path for the task. JEROS then navigates autonomously using a GPS (Global Positioning System) receiver and an INS(inertial navigation system).
The assembly robots maintain a set formation pattern, while calculating its course to perform jellyfish extermination. The advantage of this method is that there is no need for individual control of the robots. Only the leader robot requires the calculated path, and the other robots can simply follow in a formation by exchanging their location information via wireless communication (ZigBee method).
JEROS uses its propulsion speed to capture jellyfish into the grinding part on the bottom, which then suctions the jellyfish toward the propeller to be exterminated.
The field test results show that three assembly robots operating at 4 knots (7.2km/h) disposes jellyfish at the rate of about 900kg/h.
The research team has currently completed testing JEROS at Gyeongnam Masan Bay and is expected to further experiment and improve the performance at various environment and conditions.
JEROS may also be utilized for other purposes including marine patrols, prevention of oil spills and waste removal in the sea.
JEROS research has been funded by Ministry of Science, ICT and Future Planning and Ministry of Trade, Industry and Energy.
2013.09.27 View 17389 -
Transparent Glass Wall as a Touch Game Media
Professor Woo-hoon Lee
- Selected as the “Highlight” at SIGGRAPH emerging technology conference
- “An excellent example of the transparent display panel in everyday life”
A joint research team led by KAIST Industrial Design Department’s Prof. Woo-hoon Lee and Computer Sciences Prof. Ki-hyuk Lee has developed a brand new concept game media “TransWall”, which utilizes both sides of the glass wall as the touch medium.
TransWall has been chosen as the “highlight” of 2013 SIGGRAPH emerging technology conference. SIGGRAPH is a world-renowned conference in the area of computer graphics and interaction technique, last held 21st-25th July at Anaheim, in the United States.
It all started with the thought, wouldn’t it be possible to turn the glass walls surrounding us into a medium for entertainment and communication?
TransWall utilizes holographic screen film inserted between two glass sheets with a multi-touch function, onto which the image can be projected using the beam projector from both sides. Furthermore, an additional Surface Transducer attached to the glass can deliver the sound and vibration.
What seemed as an ordinary glass wall has been transformed into a multi-sensory media that can transmit and receive visual, auditory and tactile information.
TransWall can be implemented at public places such as theme parks, large shopping malls and subway stations, providing the citizens with a new form of entertainment. This touch-interaction method can also be applied to developing a variety of cultural contents in the future.
Professor Lee said, “TransWall shows an example of near-future where touch-interaction method can be utilized with the soon-to-be commercialized transparent display panel in everyday lives.”
TransWall Introduction video (https://vimeo.com/70391422)
TransWall at SIGGRAPH 2013 Display (https://vimeo.com/71718874)
Picture 1. Both sides of the glass wall can be used as a touch platform for various medias, including games.
Picture 2. TransWall attracts the interests of the audience at SIGGRAPH emerging technology.
Picture 3. Structure of TransWall
Picture 4. Photo of TransWall from side
2013.09.19 View 10318 -
Secondary, High Capacity Battery developed from Rice Husks
Rice husks, a waste product from rice polishing, has been successfully utilized as the silicon anode for use in high capacity lithium ion secondary batteries. The new silicon anode derived from rice husks exhibit superior output and lifespan.
Professor Choi Jang Wook (The Graduate School of Energy, Environment, Water and Sustainability (EEWS)) and Professor Park Seung Min (Department of Biochemistry) and their respective research teams separated naturally occurring, highly porous silica material within the rice husks and developed a 3-dimensional, highly porous silicon anode material.
The result of the research effort was published in the online edition of the Proceedings of the National Academy of Sciences (PNAS) journal, a world renowned journal in the field of natural sciences.
Silicon has attracted much attention as anode material for next generation lithium ion secondary batteries because it exhibits 3~5 times higher capacity than conventional graphene. The high capacity will pave the way to lithium secondary batteries with higher energy densities than conventional batteries. It is anticipated that the application of silicon batteries will yield electronic devices with a longer duration for use in addition to electronic vehicles boasting longer mileage.
The silicon anode is based on the 3-dimensional, highly porous structure of rice husks which remedies the problematic extreme volume expansion of conventional silicon anodes.
Utilization of inexpensive rice husks to create high value silicon anodes will cause a ripple effect on the industry and academia.
2013.08.23 View 11103
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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 16578 -
Ultra High Speed Nanomaterial Synthesis Process Developed Using Laser
Dr. Jun-Yeop, Yeo and the research team led by Professor Seung-Hwan, Ko (both of the Department of Mechanical Engineering) successfully developed a process enabling the location-determinable, ultra high speed synthesis of nanomaterials using concentrated laser beams.
The result of the research effort was published as the frontispiece in the July 9th issue of Advanced Functional Materials, a world renowned material science and engineering academic journal.
Application of the technology reduced the time needed to process nanomaterial synthesis from a few hours to a mere five minutes. In addition, unlike conventional nanomaterial synthesis processes, it is simple enough to enable mass production and commercialization.
Conventional processes require the high temperatures of 900~1,000 °C and the use of toxic or explosive vapors. Complex processes such as separation after synthesis and patterning are needed for application in electronic devices. The multi-step, expensive, environmentally unfriendly characteristics of nanomaterial synthesis served as road blocks to its mass production and commercialization.
Exposing the precursor to concentrated continuous laser beam (green wavelength) resulted in the synthesis of nanowires in the desired location; the first instance in the world to accomplish this feat. The technology, according to the research team, makes possible the production, integration and patterning of nanomaterials using a single process. Applicable to various surfaces and substrates, nanowires have been successfully synthesized on flexible plastic substrates and controlled patterning on the surface of 3-dimensional structures.
Dr. Yeo commented that the research effort has “yielded the creation of a nanomaterial synthesis process capable of synthesis, integration, pattern, and material production using light energy” and has “reduced the synthesis process time of nanomaterial to one tenths of the conventional process.” Dr. Yeo continues to devise steps to commercialize the new multifunctional electronic material and methods for mass production.
The research effort, led by Dr. Yeo and Professor Ko, received contribution from Professor Hyung-Jin Sung (KAIST Department of Mechanical Engineering), Seok-Joon Hong, a Ph.D. candidate, Hyun-Wook Kang, also a Ph.D. candidate, Professor Costas Grigoropoulos of UC Berkeley, and Dr. Dae Ho Lee. In addition, the team received support from the National Research Foundation, Ministry of Knowledge Economy, Global Frontier Program, and KAIST EEWS.
Picture I: Synthesized nanomaterials produced at a desirable location by laser beams
Picture 2: Synthesized nanomaterials built on the 3D structure by using the developed technology
Picture 3: Functional electric circuit made with synthesized nanomaterials
Picture 4: Cover page of July 9th issue of Advanced Functional Materials
2013.08.23 View 10682