Engineering
-
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 12934 -
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 13147 -
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 10904 -
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 10918 -
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 11645 -
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 12081 -
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 9993 -
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 12996 -
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 12723 -
Professor Sung-Yong Kim Receives the Young Scientist Award
Professor Sung-Yong Kim of the Department of Ocean Systems Engineering at KAIST received the Young Scientist Award for 2014 conferred by the Korean Society of Oceanography (KSO). The award was presented at the KSO’s fall conference that took place on November 6, 2014 at the campus of the Naval Academy of the Republic of Korea in Jinhae.
Professor Kim has been recognized for his outstanding research in coastal oceanography and environmental fluid mechanics. His research papers are frequently published in prestigious journals such as the Journal of Geophysical Research-Oceans by the American Geophysical Union.
2014.11.11 View 8659 -
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 8921 -
The 2014 SoC Robot Competition Took Place
Professor Hoi-Jun Yoo of the Department of Electrical Engineering at KAIST and his research team hosted a competition for miniature robots with artificial intelligence at KINTEX in Ilsan, Korea, on October 23-26, 2014.
The competition, called the 2014 SoC Robot War, showed the latest developments of semiconductor and robot technology through the robots’ presentations of the Korean martial art, Taekwondo, and hurdles race. SoC is a system on ship, an integrated circuit that holds all components of a computer or other electronic systems in a single chip. SoC robots are equipped with an artificial intelligence system, and therefore, can recognize things on their own or respond automatically to environmental changes. SoC robots are developed with the integration of semiconductor technology and robotics engineering.
Marking the thirteenth competition this year since its inception, the Robot War featured two competitions between HURO and Taekwon Robots. Under the HURO competition, participating robots were required to run a hurdle race, pass through barricades, and cross a bridge. The winning team received an award from the president of the Republic of Korea. Robots participating in the Taekwon Robot competition performed some of the main movements of Taekwondo such as front and side kicks and fist techniques. The winning team received an award from the prime minster of the Republic of Korea.
A total of 105 teams with 530 students and researchers from different universities across the country participated in preliminaries, and 30 teams qualified for the final competition.
2014.10.27 View 9621