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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 10519 -
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 9665 -
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 8770 -
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 7333 -
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 9507 -
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 10117 -
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 9637 -
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 8156 -
Distinguished Professor Sang Yup Lee Accepts an Honorary Professorship at Beijing University of Chemical Technology
Distinguished Professor Sang Yup Lee of the Department of Chemical and Biomolecular Engineering at KAIST has been appointed an honorary professor at Beijing University of Chemical Technology (BUCT). Founded in 1958, BUCT is one of the outstanding universities in mainland China, especially in chemistry studies.
In addition to the Chinese Academy of Sciences (2012), Shanghai Jiao Tong University (2013), Wuhan University (2014), and Hebei University of Technology (2014), this is the fifth honorary professorship Professor Lee has received from higher education institutions in China.
Professor Lee was recognized for his pioneering research in systems metabolic engineering of microorganisms necessary for the development of green chemical industries. He succeeded in producing succinic acid through bacterial fermentation and engineering plastic raw materials in the most effective and economical method for the first time in the world. Professor Lee also developed polylactic acid, a bio-based polymer that allows plastics to be produced through natural and renewable resources, as well as the microbial production of alkanes, an alternative to gasoline that can be produced from fatty acids.
Professor Lee has been actively working as a member of a group of global leaders supported by the World Economic Forum (WEF), serving as the Chairman of the Future of Chemicals, Advanced Materials & Biotechnology, Global Agenda Councils, WEF.
2014.11.13 View 10493 -
A KAIST Student Team Wins the ACM UIST 2014 Student Innovation Contest
A KAIST team consisted of students from the Departments of Industrial Design and Computer Science participated in the ACM UIST 2014 Student Innovation Contest and received 1st Prize in the category of People’s Choice.
The Association for Computing Machinery (ACM) Symposium on User Interface Software and Technology (UIST) is an international forum to promote innovations in human-computer interfaces, which takes place annually and is sponsored by ACM Special Interest Groups on Computer-Human Interaction (SIGCHI) and Computer Graphics (SIGGRAPH). The ACM UIST conference brings together professionals in the fields of graphical and web-user interfaces, tangible and ubiquitous computing, virtual and augmented reality, multimedia, and input and output devices.
The Student Innovation Contest has been held during the UIST conference since 2009 to innovate new interactions on state-of-the-art hardware. The participating students were given with the hardware platform to build on—this year, it was Kinoma Create, a JavaScript-powered construction kit that allows makers, professional product designers, and web developers to create personal projects, consumer electronics, and "Internet of Things" prototypes. Contestants demonstrated their creations on household interfaces, and two winners in each of three categories -- Most Creative, Most Useful, and the People’s Choice -- were awarded.
Utilizing Kinoma Create, which came with a built-in touchscreen, WiFi, Bluetooth, a front-facing sensor connector, and a 50-pin rear sensor dock, the KAIST team developed a “smart mop,” transforming the irksome task of cleaning into a fun game. The smart mop identifies target dirt and shows its location on the display built in the rod of a mop. If the user turns on a game mode, then winning scores are gained wherever the target dirt is cleaned.
The People’s Choice award was decided by conference attendees, and they voted the smart mop as their most favorite project.
Professor Tek-Jin Nam of the Department of Industrial Design at KAIST, who advised the students, said, "A total of 24 teams from such prestigious universities as Carnegie Mellon University, Georgia Institute of Technology, and the University of Tokyo joined the contest, and we are pleased with the good results. Many people, in fact, praised the integration of creativity and technical excellence our have shown through the smart mop.”
Team KAIST: pictured from right to left, Sun-Jun Kim, Se-Jin Kim, and Han-Jong Kim
The Smart Mop can clean the floor and offer users a fun game.
2014.11.12 View 10262 -
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 9543 -
Professor Joong-Keun Park Receives SeAH Heam Academic Award
Professor Joong-Keun Park of the Department of Materials Science and Engineering at KAIST received an award from SeAH Steel Corp. in recognition of his academic achievements in the field of metallic and materials engineering.
The award was presented at the 2014 Fall Conference of the Korean Institute of Metals and Materials which took place on October 22-24 at the Kangwon Land Convention Hotel.
The award, called “SeAH Heam Academic Award,” is given annually to a scholar who has contributed to the development of new metal and polymer composite materials and its related field in Korea. Following the award ceremony, Professor Park gave a keynote speech on ferrous metals for automotive materials.
2014.11.04 View 7450