AT
-
Broadband and Ultrathin Polarization Manipulators Developed
Professor Bumki Min from the Department of Mechanical Engineering at KAIST has developed a technology that can manipulate a polarized light in broadband operation with the use of a metamaterial.
It is expected that this technology will lead to the development of broadband optical devices that can be applied to broadband communication and display.
When an object or its structure is analyzed by using a polarized light such as a laser, the results are generally affected by the polarized state of the light. Therefore, in an optics laboratory, the light is polarized by various methods.
In such cases, researchers employ wave plates or photoactive materials. However, the performance of these devices depend vastly on wavelength, and so they are not suitable to be used as a polarizer, especially in broadband.
There were many attempts to make artificial materials that are very photoactive by using metamaterials which have a strong resonance. Nonetheless, because the materials had an unavoidable dispersion in the resonance frequency, they were not adequate for broadband operation.
Professor Min’s research team arranged and connected helical metamaterials that are smaller than the wavelength of light. They verified theoretically and experimentally that polarized light can be constantly rotated regardless of the wavelength by super-thin materials that have thickness less than one-tenth of the wavelength of the light. The experiment which confirmed the theory was conducted in the microwave band.
Broadband polarized rotational 3D metamaterials were found to rotate the polarized microwave within the range of 0.1 GHz to 40 GHz by 45 degrees regardless of its frequency. This nondispersive property is quite unnatural because it is difficult to find a material that does not change in a wide band.
In addition, the research team materialized the broadband nondispersive polarized rotational property by designing the metamaterial in a way that it has chirality, which determines the number of rotations proportional to the wavelength.
Professor Min said, “As the technology is able to manipulate ultrathin polarization of light in broadband, it will lead to the creation of ultra-shallow broadband optical devices.”
Sponsored by the Ministry of Science, ICT and Future Planning of the Republic of Korea and the National Research Foundation of Korea, this research was led by a PhD candidate, Hyun-Sung Park, under the guidance of Professor Min. The research findings were published online in the November 17th issue of Nature Communications.
Figure 1 – Broadband and Ultrathin Polarization Manipulators Produced by 3D Printer
Figure 2 – Concept of Broadband and Ultrathin Polarization Manipulators
2014.12.03 View 11609 -
Structure of Neuron-Connecting Synaptic Adhesion Molecules Discovered
A research team has found the three-dimensional structure of synaptic adhesion molecules, which orchestrate synaptogenesis. The research findings also propose the mechanism of synapses in its initial formation. Some brain diseases such as obsessive compulsive disorder (OCD) or bipolar disorders arise from a malfunction of synapses. The team expects the findings to be applied in investigating pathogenesis and developing medicines for such diseases.
The research was conducted by a Master’s candidate Kee Hun Kim, Professor Ji Won Um from Yonsei University, and Professor Beom Seok Park from Eulji University under the guidance of Professor Homin Kim from the Graduate School of Medical Science and Engineering, KAIST, and Professor Jaewon Ko from Yonsei University. Sponsored by the Ministry of Science, ICT and Future Planning and the National Research Foundation of Korea, the research findings were published online in the November 14th issue of Nature Communications.
A protein that exists in the neuronal transmembrane, Slitrk, interacts with the presynaptic leukocyte common antigen-related receptor protein tyrosine phosphatases (LAR-RPTPs) and forms a protein complex. It is involved in the development of synapses in the initial stage, and balances excitatory and inhibitory signals of neurons.
It is known that a disorder in those two proteins cause a malfunction of synapses, resulting in neuropsychosis such as autism, epilepsy, OCD, and bipolar disorders. However, because the structure as well as synaptogenic function of these proteins were not understood, the development of cures could not progress.
The research team discovered the three-dimensional structure of two synaptic adhesion molecules like Slitrk and LAR-RPTPs and identified the regions of interaction through protein crystallography and transmission electron microscopy (TEM). Furthermore, they found that the formation of the synapse is induced after the combination of two synaptic adhesion molecules develops a cluster.
Professor Kim said, “The research findings will serve as a basis of understanding the pathogenesis of brain diseases which arises from a malfunction of synaptic adhesion molecules. In particular, this is a good example in which collaboration between structural biology and neurobiology has led to a fruitful result.” Professor Ko commented that “this will give new directions to synaptic formation-related-researches by revealing the molecular mechanism of synaptic adhesion molecules.”
Figure 1: Overview of the PTPd Ig1–3/Slitrk1 LRR1 complex.
Figure 2: Representative negative-stained electron microscopy images of Slitrk1 Full ectodomain (yellow arrows indicate the horseshoe-shaped LRR domains). The typical horseshoe-shaped structures and the randomness of the relative positions of each LRR domain can be observed from the two-dimensional class averages displayed in the orange box.
Figure 3: Model of the two-step presynaptic differentiation process mediated by the biding of Slitrks to LAR-RPTPs and subsequent lateral assembly of trans-synaptic LAR-RPTPs/Slitrik complexes.
2014.11.28 View 11992 -
Breakthrough in Flexible Electronics Enabled by Inorganic-based Laser Lift-off
Flexible electronics have been touted as the next generation in electronics in various areas, ranging from consumer electronics to bio-integrated medical devices. In spite of their merits, insufficient performance of organic materials arising from inherent material properties and processing limitations in scalability have posed big challenges to developing all-in-one flexible electronics systems in which display, processor, memory, and energy devices are integrated. The high temperature processes, essential for high performance electronic devices, have severely restricted the development of flexible electronics because of the fundamental thermal instabilities of polymer materials.
A research team headed by Professor Keon Jae Lee of the Department of Materials Science and Engineering at KAIST provides an easier methodology to realize high performance flexible electronics by using the Inorganic-based Laser Lift-off (ILLO).
The ILLO process involves depositing a laser-reactive exfoliation layer on rigid substrates, and then fabricating ultrathin inorganic electronic devices, e.g., high density crossbar memristive memory on top of the exfoliation layer. By laser irradiation through the back of the substrate, only the ultrathin inorganic device layers are exfoliated from the substrate as a result of the reaction between laser and exfoliation layer, and then subsequently transferred onto any kind of receiver substrate such as plastic, paper, and even fabric.
This ILLO process can enable not only nanoscale processes for high density flexible devices but also the high temperature process that was previously difficult to achieve on plastic substrates. The transferred device successfully demonstrates fully-functional random access memory operation on flexible substrates even under severe bending.
Professor Lee said, “By selecting an optimized set of inorganic exfoliation layer and substrate, a nanoscale process at a high temperature of over 1000 °C can be utilized for high performance flexible electronics. The ILLO process can be applied to diverse flexible electronics, such as driving circuits for displays and inorganic-based energy devices such as battery, solar cell, and self-powered devices that require high temperature processes.”
The team’s results were published in the November issue of Wiley’s journal, ‘ Advanced Materials, ’ as a cover article entitled “ Flexible Crossbar-Structured Resistive Memory Arrays on Plastic Substrates via Inorganic-Based Laser Lift-Off.”
( http://onlinelibrary.wiley.com/doi/10.1002/adma.201402472/abstract )
This schematic picture shows the flexible crossbar memory developed via the ILLO process.
This photo shows the flexible RRAM device on a plastic substrate.
2014.11.26 View 10245 -
Elsevier Selects a KAIST Graduate's Paper as the Top Cited Papers in 2011-2012
Dr. Myung-Won Seo, a graduate from the Department of Chemical and Bimolecular Engineering at KAIST, published a paper in January 2011 in Chemical Engineering Journal, which was entitled “Solid Circulation and Loop-seal Characteristics of a Dual Circulating Fluidized Bed: Experiments and CFD Simulation.” His paper was selected by Elsevier as the Top Cited Papers of 2011-2012. The Chemical Engineering Journal is a renowned peer-reviewed journal issued by Elsevier.
Dr. Seo published another paper, “CFD Simulation with Experiments in a Dual Circulating Fluidized Bed Gasifier,” in January 2012 in Computers & Chemical Engineering, which was also selected as the Most Downloaded Papers in 2012-2013.
Dr. Seo graduated with a doctoral degree from KAIST in 2011. He is currently working at the Clean Fuel Laboratory, the Korea Institute of Energy Research, Daejeon, as a researcher. His research areas are coal gasification, upgrading, and liquefaction, as well as energy and chemical production from low-grade fuels such as biomass and wastes.
2014.11.24 View 9734 -
KAIST Robotic Art: Exhibit called "Artificial Brain, Robots Evolve"
It is not difficult to find the desire to create a Neoanthropinae in the history of mankind. Humans evolve through man-made extensions and live by self-training them. This is Seung Hyun Son’s description which encourages us to discuss the changes man-made humanoids would bring to our future lives. He depicts this in “Theory of Evolution: From mankind to humanoid” in the “Artificial Brain, Robots Evolve” exhibition in the KI Building, KAIST, from 21 November 2014 to 8 February 2015.
KAIST's Art and Design Committee (led by President Myung Seok Kim) is holding the third experimental art exhibition based on the integration of science and art. The previous exhibition themes were “See the Sky” in 2012 and “Life is Beautiful” in 2013. The exhibition is divided into five subtopics: Move, Feel, Think, Express, and Experiment in Imagination.
The exhibits are by 17 artists including Nam June Paik, Nancy Lang, and KAIST Professor Myung Seok Kim. The main exhibits include “Cloud Face,” by Seung Baek Shin and Yong Hoon Kim, that shows up as error on computer but can be seen by human eyes and “Brains in Vat," by Boo Rok Lee and Myung Chul Kim based on KAIST's robotic lab’s materials and motif. Also, “The May of My Life” by Professor Myung Seok Kim’s lab reminds us of the relationship between robot and human.
President Myung Seok Kim said, “The range of content in cultural art will inspire students’ imagination.” He continued, “I hope this exhibition will awaken both scientific ideas and artistic sense.”
The opening ceremony of the exhibition will be held from 14:00, 21 November. The “Artificial Brain, Robots Evolve” exhibition is hosted by the Daejeon Museum of Art and sponsored by National Museum of Modern and Contemporary Art and Soma Museum.
Pictures from top to bottom are Cloud Face, Brains in Vat, The May of My Life_1, and The May of My Life_2.
2014.11.21 View 7957 -
The 2014 Wearable Computer Competition Takes Place at KAIST
“This is a smart wig for patients who are reluctant to go outdoors because their hair is falling out from cancer treatment.”
A graduate student from Sungkyunkwan University, Jee-Hoon Lee enthusiastically explains his project at the KAIST KI Building where the 2014 Wearable Computer Competition was held. He said, “The sensor embedded inside the wig monitors the heart rate and the body temperature, and during an emergency, the device warns the patient about the situation. The product emphasizes two aspects; it notifies the patient in emergency situations, and it encourages patients to perform outdoor activities by enhancing their looks.”
The the tenth anniversary meeting of the 2014 Wearable Computer Competition took place at the KAIST campus on November 13-14, 2014.
A wearable computer is a mobile device designed to be put on the body or clothes so that a user can comfortably use it while walking. Recently, these devices that are able to support versatile internet-based services through smartphones are receiving a great deal of attention.
Wearable devices have been employed in two categorizes: health checks and information-entertainment. In this year’s competition, six healthcare products and nine information-entertainment products were exhibited.
Among these products, participants favored a smart helmet for motorcycle drivers. The driver can see through a rear camera with a navigation screen of the smartphone and text messages through the screen installed in the front glass of the helmet. Another product included a uniform that can control presentation slides by means of motion detection and voice recognition technology. Yet another popular device offered an insole to guide travelers to their destination with the help of motion sensors.
The chairman of the competition, Professor Hoi-Jun Yoo from the Department of Electrical Engineering at KAIST said, “Wearable devices such as smart watches, glasses, and clothes are gaining interest these days. Through this event, people will have a chance to look at the creativity of our students through the display of their wearable devices. In turn, these devices will advance computer technology.”
The third annual wearable computer workshop on convergence technology of wearable computers followed the competition. In the workshop, experts from leading information technology companies such as Samsung Electronics, LG Electronics, and KT Corporation addressed the convergence technology of wearable computers and trends in the field.
2014.11.19 View 10466 -
3D Printer Developed by KAIST Undergraduate Students
More than 100 Pre-orders Prior to Product Launch Made
KAIST undergraduate students received more than 100 pre-orders before the launch for 3D printers they developed and became a hot topic of interest.
KAIST Research Institute for Social Technology and Innovations (Head Hong-Kyu Lee) had a launch party at Daejeon Riviera Hotel on 17 November 2014 for “Commercial Delta 3D Printer” developed by KAIST undergraduate students inviting around 50 businesses, buyers and representatives of 3D Printing Industry Association.
“3D Printer” uses blueprints of products such as toys, mug cups and chairs to make 3D objects and is thought to be revolutionary technology in manufacturing industry. The interest has grown as recent printers could print even fruits and cosmetics.
The printing structure of 3D printer can be divided roughly into horizontal Mendel method and Delta method. KAIST students focused on the Delta method to give a differentiated product from 90% of commercial products that use Mendel method.
First, the students focused on lowering the cost of unit price by using self-developed components. The carriage (transport machine) of the product is replaced by self-developed components instead of bearing to reduce the noise and the linking method was changed to beads from loop guide to increase the completeness of the printed product. Also, an auto-levelling is loaded to ensure the nozzle and the bed is parallel and hence increasing convenience for the users. Further, the printer, designed by a product designer in Germany, is linked to a smartphone application for blueprints.
A student in the development team, Seokhyeon Seo (Department of Computer Science, 3rd Year Undergraduate) said, “The biggest merits of the product are lowering the price to a 1/3 by using self-developed components and reducing the noise.” He continued, “By using a smartphone application, anyone can easily design the product. So it is applicable to use for education or at home”
In the exhibit, “3D Printing Korea 2014,” in Coex, Seoul the printer had a preview demonstration, and received more than 100 pre-orders from educational and business training institutions. Further, buyers from Canada and the US requested opening agencies in their countries.
KAIST Research Institute for Social Technology and Innovations Head Hong-Kyu Lee said, “3D printing is an innovative technology that could bring the 3rd industrial revolution.” He continued, “It is still early days but the demand will increase exponentially.”
This project was a research project of KAIST Research Institute for Social Technology and Innovations led by a development team consisting of 4 undergraduate students of KAIST, one student from University of Oxford and one German product designer.
Students in the picture below are Won-Hoi Kim (Department of Mechanical Engineering), Sung-Hyun Cho (Department of Mechanical Engineering), and Suk-Hyun Seo (Department of Computer Science) from left to right.
2014.11.19 View 11026 -
Eggshell-like Cell Encapsulation and Degradation Technology Developed
Some bacteria form endospores on cell walls to protect their DNA in case of nutrient deficiency. When an endospore meets a suitable environment for survival, the cell can revert to the original state from which it can reproduce.
The technique that can artificially control such phenomenon was developed by an international team of researchers. At first, a cell is wrapped and preserved like an egg. When the cell is needed, the technique allows the endospore to decompose while it is alive. Future applications for this technique include cell-based biosensor, cell therapy, and biocatalyst processes.
Professors Insung Choi and Younghoon Lee from the Department of Chemistry at KAIST as well as and Professor Frank Caruso from the University of Melbourne developed this technique which permits a cell to stay alive by coating it with film on a nanometer scale and then to be decomposed while it is alive.
The research finding was published in the November 10th issue of Angewandte Chemie International Edition as the lead article.
Cell encapsulation allows researchers to capture a cell in a tight capsule while it is alive. It is highly recognized in cell-based applications where the control of cell stability and cell-division is the biggest issue.
Traditional cell encapsulation methods utilized organic film or inorganic capsules that are made of organic film moldings. Although these films tightly closed around the cell, because they were not easily decomposable, it was difficult to apply the method.
The research team succeeded in encapsulating each cell in a metal-polyphenol film by mixing tannic acid and iron ion solution with yeast cells.
Usually extracted from oak barks or grape peels, tannic acid is a natural substance. It forms a metal-polyphenol film within ten seconds when it meets iron ions due to its high affinity with cells. Cells encapsulated with this film presented high survival rates. Since the film forms quickly in a simple manner, it was possible to obtain large amount of encapsulated cells.
The research team also found that the metal-polyphenol film was stable in neutral pH, but is easily degradable under a weak acidic condition. Using this property, they were able to control cell division by restoring the cell to its pre-encapsulated state at a desired moment.
Protecting the cell from the external environment like an egg shell, the metal-polyphenol film protected the cell against foreign conditions such as lytic enzymes, extended exposure to UV radiation, and silver nanoparticles. The research indicated that the encapsulated cells had a high survival rate even under extreme environments.
Professor Lee said that “not only the cells remain alive during the encapsulation stage, but also they can be protected under extreme environment.” He added, “This is an advanced cell encapsulation technology that allows controlling cell-division of those cells through responsive shell degradation on-demand.”
Professor Choi commented, “Although the cell encapsulation technology is still in its infancy, as the technology matures the application of cell-manipulation technology will be actualized.” He highlighted that “it will serve as a breakthrough to problems faced by cell-based applications.”
Sponsored by the Ministry of Science, ICT and Future Planning and the National Research Foundation of Korea, the research was led by two Master’s candidates, Ji Hun Park and Kyung Hwan Kim, under the joint guidance of research professors from KAIST and the University of Melbourne.
Figure 1: Lead article of Angewandte Chemie
Background: Shows a live native yeast (in green) encapsulated in a metal-polyphenol film (in red) illustrating the vitality of the yeast
Front: A native yeast at each encapsulation stage
Pictured on the bottom left is a cell prior to encapsulation. Following the red arrow, the native yeast is in purple to show metal-polyphenol film formed around the cell. The cell after the green arrow is a visualization of the degradation of the film in weak acidic condition.
Figure 2: A mimetic diagram of cell encapsulation with a metal-polyphenol film
Top: A native yeast before encapsulation
Middle: A native yeast encapsulated with Tannic Acid-Fe (III) Nanoshell – cell-division of the encapsulated cell is controlled by pH and the shell is protected against silver nanoparticle, lytic enzyme, and UV-C
Bottom: Shell degradation on-demand depending on pH
2014.11.18 View 10403 -
The Website of the KAIST Industrial Design Department Receives a Design Award
The 10th QS-Apple Higher Education Conference and Exhibition took place on November 11-13, 2014 in Taipei, Taiwan. The conference was hosted by Quacquarelli Symonds, a British company specializing in education, which publishes annually its world university rankings. Apple stands for Asia Pacific Professional Leaders in Education.
The QS-Apple conference supports the internationalization of Asia Pacific universities by providing opportunities for networking, exchanging best practices, and discussing recent developments in higher education. During the conference, the organizers presented the Creative Awards for best international education promotional designs in four categories: Website Pages, Video, Print Advertisement, and International Student Recruitment Brochures.
KAIST’s Industrial Design Department received the Best Website Pages Award for their website in recognition of high levels of user convenience and satisfaction as well as English language services. A total of 39 universities in the Asia and Pacific region competed in this category, and Nanyang Technological University in Singapore came in second place, followed by Hong Kong Baptist University in third.
2014.11.13 View 8985 -
President Steve Kang will serve as the Chairman of Global Agenda Council on the Future of Electronics of the World Economic Forum
President Steve Kang of KAIST has been appointed to the Chairman of the Global Agenda Council (GAC) on the Future of Electronics of the World Economic Forum (WEF). He will serve the position for two years until September 2016.
President Kang and WEF council members co-hosted, with the government of the United Arab Emirates (UAE), the Future Circles Initiative, a future-focused, innovative brainstorming conference to help find strategies and ideas for the development of UAE. The conference took place on November 11-12, 2014 at the Mina Al Salam Hotel in Dubai.
WEF has about 80 GACs. Each council consists of 15 experts and thought leaders from the academia, industry, government, business, and non-profit sector and deals with specific issues that are important and relevant to the global community such as ageing, artificial intelligence and robotics, brain research, food and nutrition security, education, social media, and future of chemicals, advanced materials and biotechnology.
President Kang was recognized for his contribution to the advancement of science and higher education as an engineer, scholar, and professor. He led the development of the world’s premier CMOS 32-bit microprocessors while working at the AT&T Bell Laboratories. He also taught and conducted research at the University of California, Santa Cruz, and the University of Illinois, Urbana-Champaign. President Kang served as the chancellor of the University of California at Merced from March 2007 to June 2011.
2014.11.11 View 9225 -
KAIST and the International Institute for Applied Systems Analysis Agree to Cooperate
KAIST signed a cooperation agreement with the International Institute for Applied Systems Analysis (IIASA) on October 29, 2014 at the president’s office.
Established in 1972 and based in Austria as a non-governmental research organization, IIASA is an international scientific institute that conducts policy-oriented research into global problems such as climate change, energy security, or population aging. IIASA examines such issues and devises strategies for cooperative action unconstrained by political and national self-interest.
Dr. Pavel Kabat, the Director General and CEO of IIASA, headed a delegation that visited KAIST to attend the signing ceremony of the agreement. He said, “KAIST has been known as a leading research university, and its strength in the development of green technology and environmental policy will benefit our institution. In particular, we expect to see vibrant exchanges of knowledge and researchers with the Graduate School of Green Growth (GSGG) and the Graduate School of EEWS (energy, environment, water, and sustainability) at KAIST.”
The two organizations will implement joint research projects in the diffusion analysis of green technology, the development and improvement of evaluation models to integrate economy, energy, and environment, the development of an analysis system for water resources, and the establishment of academic workshops and conferences.
The Dean of GSGG, Professor Jae-Kyu Lee said, “IIASA is a well-respected international organization with accumulated knowledge about analysis and prediction techniques. With this agreement, we hope that KAIST will intensify its research capacity in environmental science and lead education and research in green growth and environmental technology.”
The picture below shows Dr. Pavel Kabat, the Director General and CEO of IIASA, on the left and President Steve Kang of KAIST on the right holding the signed agreement with professors from GSGG and EEWS Graduate School including Professor Jae-Kyu Lee, to the right of President Kang.
2014.11.05 View 10594 -
The Hancom and KAIST Research Center Opens
KAIST and Hancom, Inc., an office suite developer in Korea, established a joint research center to develop software technology and its related industry. President Steve Kang of KAIST, Sang-Chul Kim, the Chief Executive Officer (CEO) of Hancom, and professors from the computer science department at KAIST attended a ceremony to celebrate the opening of the center.
KAIST and Hancom signed a memorandum of understanding in April this year for the development of software industry in Korea, and based on the agreement, the two institutions identified five research projects and created a research center to implement them effectively.
President Kang said, “I hope that the research center will serve as a good example of university and industry collaboration. To that end, we will provide our support to the maximum extent possible to lead the software industry in Korea. We are also planning to hold a joint workshop on the latest trends in software technology and on the education of software developers.”
Established in 1990, Hancom created the native word processor for the Korean language called “Hangul.”
2014.11.05 View 8032