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KAIST Researchers Develops Hyper-Stretchable Elastic-Composite Energy Harvester
A research team led by Professor Keon Jae Lee (http://fand.kaist.ac.kr) of the Department of Materials Science and Engineering at KAIST has developed a hyper-stretchable elastic-composite energy harvesting device called a nanogenerator.
Flexible electronics have come into the market and are enabling new technologies like flexible displays in mobile phone, wearable electronics, and the Internet of Things (IoTs). However, is the degree of flexibility enough for most applications? For many flexible devices, elasticity is a very important issue. For example, wearable/biomedical devices and electronic skins (e-skins) should stretch to conform to arbitrarily curved surfaces and moving body parts such as joints, diaphragms, and tendons. They must be able to withstand the repeated and prolonged mechanical stresses of stretching. In particular, the development of elastic energy devices is regarded as critical to establish power supplies in stretchable applications. Although several researchers have explored diverse stretchable electronics, due to the absence of the appropriate device structures and correspondingly electrodes, researchers have not developed ultra-stretchable and fully-reversible energy conversion devices properly.
Recently, researchers from KAIST and Seoul National University (SNU) have collaborated and demonstrated a facile methodology to obtain a high-performance and hyper-stretchable elastic-composite generator (SEG) using very long silver nanowire-based stretchable electrodes. Their stretchable piezoelectric generator can harvest mechanical energy to produce high power output (~4 V) with large elasticity (~250%) and excellent durability (over 104 cycles). These noteworthy results were achieved by the non-destructive stress- relaxation ability of the unique electrodes as well as the good piezoelectricity of the device components. The new SEG can be applied to a wide-variety of wearable energy-harvesters to transduce biomechanical-stretching energy from the body (or machines) to electrical energy.
Professor Lee said, “This exciting approach introduces an ultra-stretchable piezoelectric generator. It can open avenues for power supplies in universal wearable and biomedical applications as well as self-powered ultra-stretchable electronics.”
This result was published online in the March issue of Advanced Materials, which is entitled “A Hyper-Stretchable Elastic-Composite Energy Harvester.”
YouTube Link: “A hyper-stretchable energy harvester”
https://www.youtube.com/watch?v=EBByFvPVRiU&feature=youtu.be
Figure: Top row: Schematics of hyper-stretchable elastic-composite generator enabled by very long silver nanowire-based stretchable electrodes.
Bottom row: The SEG energy harvester stretched by human hands over 200% strain.
2015.04.14 View 12769 -
KAIST Connects CNU with Pedestrian Walkway
KAIST and Chungnam National University (CNU) built a pedestrian walkway ("pedway") that physically brings them closer than ever. Opened on April 13, 2015, the KAIST-CNU Pedway now offers members of the two universities a quick and scenic road to walk or bike for their campus visit.
The 180-meter-strip, with a width of four meters, starts from KAIST’s student dormitories, Narae and Mir Halls, and arrives at the backyard of the College of Agriculture and Life Sciences building at CNU. For security and safety precaution, emergency alarms, CCTVs and security lights are installed along the path.
A commemorative event celebrating the opening of the pedway was held on April 15, 2015 at the KAIST campus. Along with senior administrators of the two universities, In-Sik Kim, Chairman of Daejeon City Assembly, Choon-Hee Baek, Deputy Mayor for Political Affairs of Daejeon, President Steve Kang of KAIST, and President Sang-Chul Jung of CNU will attend the event.
CNU is located just a twenty-minute walk from KAIST, but the two universities have had little interaction. To promote more collaboration and exchange, KAIST and CNU signed a memorandum of understanding on the cooperation of education, research, and medicine in June 2014.
With the KAIST-CNU Pedway as the stepping stone, the two universities will strengthen their cooperation in academic information exchange allowing access to their libraries and establishing the Graduate School of Integrated Medical Science in Sejong.
President Kang said, “Universities should not be isolated islands from the local community, but should act as bridges between different districts.” He continued, “I hope this pedway can be the starting point.”
President Jung said, “I hope this road can remove the wall between KAIST and Chungnam National University, in terms of knowledge, information, and people. I further hope that it will become the symbol and token of unity of the two universities.”
2015.04.13 View 7418 -
KAIST Hosts a Symposium on IPR
KAIST’s Graduate School of Future Strategy (http://futures.kaist.ac.kr) hosted a symposium entitled “Future Strategies to Grow Korea as the Hub for the World’s Intellectual Property Rights (IPRs)” under the theme of “Patent Laws and a Revised Bill for the Code of Civil Procedures” in the National Assembly’s Memorial Hall on April 9, 2015.
Experts who attended the symposium included Professor James Dator, Director of the Hawaii Research Center for Futures Studies, Sang-Wook Han, a lawyer and Vice President of Korea Intellectual Property Protection Association (KIPRA), and Min Seo, a former Chairman of Civil Law Revision Commission of the Ministry of Justice, Korea.
The event consisted of special lectures, patent law presentations, a revised bill for the code of civil procedures in patent law, and a general discussion forum. Professor Dator, the keynote speaker, addressed the future of intellectual property. San-Wook Han (KIPRA) talked about new and effective changes in Korean patent law such as the compensation against IPR violations and the reduction of legal burden of proof in IPR disputes. Min Seo from the Ministry of Justice moderated a panel of eight members, which offered an in-depth discussion on the revised bill.
A ceremony for “The Third Future Strategy Award” was also held at the symposium. Yeon-Soo Park, former Administrator of the National Emergency Management Agency, received the award for his work on the Northeast Asian International Business Center City Project which enabled the construction of Incheon International Airport and Songdo International City.
2015.04.09 View 9907 -
Wall Climbing Quadcopter by KAIST Urban Robotics Lab
Popular Science, an American monthly magazine devoted to general readers of science and technology, published “Watch This Creepy Drone Climb A Wall” online describing a drone that can fly and climb walls on March 19, 2015. The drone is the product of research conducted by Professor Hyun Myung of the Department of Civil and Environmental Engineering at KAIST. The flying quadcopters can turn into wall-crawling robots, or vice versa, when carrying out such assignments as cleaning windows or inspecting a building’s infrastructure. Professor Myung leads the KAIST Urban Robotics Lab (http://urobot.kaist.ac.kr/). For a link to the article, see http://www.popsci.com/watch-drone-climb-wall-video.
Another Popular Science article (posted on April 3, 2015), entitled “South Korea Gets Ready for Drone-on-Drone Warfare with North Korea,” describes a combat system of drones against hostile drones. Professor Hyunchul Shim of the Aerospace Engineering Department at KAIST developed the anti-drone system. He currently heads the Unmanned System Research Group, FDCL, http://unmanned.kaist.ac.kr/) and the Center of Field Robotics for Innovation, Exploration, aNd Defense (C-FRIEND).
2015.04.07 View 11301 -
Anti-Cancer Therapy Delivering Drug to an Entire Tumor Developed
KAIST’s Department of Bio and Brain Engineering Professor Ji-Ho Park and his team successfully developed a new highly efficacious anti-cancer nanotechnology by delivering anti-cancer drugs uniformly to an entire tumor. Their research results were published in Nano Letters online on March 31, 2015.
To treat inoperable tumors, anti-cancer medicine is commonly used. However, efficient drug delivery to tumor cells is often difficult, treating an entire tumor with drugs even more so.
Using the existing drug delivery systems, including nanotechnology, a drug can be delivered only to tumor cells near blood vessels, leaving cells at the heart of a tumor intact. Since most drugs are injected into the bloodstream, tumor recurrence post medication is frequent.
Therefore, the team used liposomes that can fuse to the cell membrane and enter the cell. Once inside liposomes the drug can travel into the bloodstream, enter tumor cells near blood vessels, where they are loaded to exosomes, which are naturally occurring nanoparticles in the body. Since exosomes can travel between cells, the drug can be delivered efficiently into inner cells of the tumor.
Exosomes, which are secreted by cells that exist in the tumor microenvironment, is known to have an important role in tumor progression and metastasis since they transfer biological materials between cells. The research team started the investigation recognizing the possibility of delivering the anti-cancer drug to the entire tumor using exosomes.
The team injected the light-sensitive anti-cancer drug using their new delivery technique into experimental mice. The researchers applied light to the tumor site to activate the anti-cancer treatment and analyzed a tissue sample. They observed the effects of the anti-cancer drug in the entire tumor tissue.
The team’s results establish a ground-breaking foothold in drug delivery technology development that can be tailored to specific diseases by understanding its microenvironment. The work paves the way to more effective drug delivery systems for many chronic diseases, including cancer tumors that were difficult to treat due to the inability to penetrate deep into the tissue.
The team is currently conducting experiments with other anti-cancer drugs, which are being developed by pharmaceutical companies, using their tumor-penetrating drug delivery nanotechnology, to identify its effects on malignant tumors.
Professor Park said, “This research is the first to apply biological nanoparticles, exosomes that are continuously secreted and can transfer materials to neighboring cells, to deliver drugs directly to the heart of tumor.”
Picture: Incorporation of hydrophilic and hydrophobic compounds into membrane vesicles by engineering the parental cells via synthetic liposomes.
2015.04.07 View 11039 -
Professor Rim Presents at IAEA Workshop in Vienna
Professor Chun-Taek Rim of the Department of Nuclear and Quantum Engineering at KAIST recently attended the International Atomic Energy Agency (IAEA)’s workshop on the Application of Wireless Technologies in Nuclear Power Plant Instrumentation and Control System. It took place on March 30-April 2, 2015, in Vienna, Austria.
Representing Korea, Professor Rim gave a talk entitled “Highly Reliable Wireless Power and Communications under Severe Accident of Nuclear Power Plants (NPPs).” About 20 industry experts from 12 countries such as AREVA (France), Westinghouse (US), Oak Ridge National Laboratory (US), Hitachi (Japan), and ENEA (Italy) joined the meeting.
The IAEA hosted the workshop to explore the application of wireless technology for the operation and management of NPPs. It formed a committee consisting of eminent professionals worldwide in NPP instrumentation and control systems, communications, and nuclear power to examine this issue in-depth and to conduct various research projects for the next three years.
In particular, the committee will concentrate its research on improving the reliability and safety of using wireless technology, not only in the normal operation of nuclear plants but also in extreme conditions such as the Fukushima Daiichi nuclear accident. The complementation, economic feasibility, and standardization of NPPs when applying wireless technology will be also discussed.
Professor Rim currently leads the Nuclear Power Electronics
and Robotics Lab at KAIST (http://tesla.kaist.ac.kr/index_eng.php?lag=eng).
Picture 1: Professors Rim presents his topic at the IAEA Workshop in Vienna.
Picture 2: The IAEA Workshop Participants
2015.04.07 View 11165 -
Novel Photolithographic Technology Enabling 3D Control over Functional Shapes of Microstructures
Professor Shin-Hyun Kim and his research team in the Department of Chemical and Biomolecular Engineering at KAIST have developed a novel photolithographic technology enabling control over the functional shapes of micropatterns using oxygen diffusion.
The research was published online in the March 13th issue of Nature Communications and was selected as a featured image for the journal.
Photolithography is a standard optical process for transferring micropatterns on to a substrate by exposing specific regions of the photoresist layer to ultraviolet (UV) light. It is used widely throughout industries that require micropatterns, especially in the semiconductor manufacturing industry.
Conventional photolithography relied on photomasks which protected certain regions of the substrate from the input UV light. Areas covered by the photomasks remain intact with the base layer while the areas exposed to the UV light are washed away, thus creating a micropattern. This technology was limited to a two-dimensional, disc-shaped design as the boundaries between the exposed and roofed regions are always in a parallel arrangement with the direction of the light.
Professor Kim’s research team discovered that: 1) the areas exposed to UV light lowered the concentration of oxygen and thus resulted in oxygen diffusion; and 2) manipulation of the diffusion speed and direction allowed control of the growth, shape and size of the polymers. Based on these findings, the team developed a new photolithographic technology that enabled the production of micropatterns with three-dimensional structures in various shapes and sizes.
Oxygen was considered an inhibitor during photopolymerization. Photoresist under UV light creates radicals which initialize a chemical reaction. These radicals are eliminated with the presence of oxygen and thus prevents the reaction. This suggests that the photoresist must be exposed to UV light for an extended time to completely remove oxygen for a chemical reaction to begin.
The research team, however, exploited the presence of oxygen. While the region affected by the UV light lowered oxygen concentration, the concentration in the untouched region remained unchanged. This difference in the concentrations caused a diffusion of oxygen to the region under UV light.
When the speed of the oxygen flow is slow, the diffusion occurs in parallel with the direction of the UV light. When fast, the diffusion process develops horizontally, outward from the area affected by the UV light. Professor Kim and his team proved this phenomenon both empirically and theoretically. Furthermore, by injecting an external oxygen source, the team was able to manipulate diffusion strength and direction, and thus control the shape and size of the polymer. The use of the polymerization inhibitors enabled and facilitated the fabrication of complex, three-dimensional micropatterns.
Professor Kim said, “While 3D printing is considered an innovative manufacturing technology, it cannot be used for mass-production of microscopic products. The new photolithographic technology will have a broad impact on both the academia and industry especially because existing, conventional photolithographic equipment can be used for the development of more complex micropatterns.” His newest technology will enhance the manufacturing process of three-dimensional polymers which were considered difficult to be commercialized.
The research was also dedicated to the late Professor Seung-Man Yang of the Department of Chemical and Biomolecular Engineering at KAIST. He was considered one of the greatest scholars in Korea in the field of hydrodynamics and colloids.
Picture 1: Featured Image of Nature Communications, March 2015
Picture 2: Polymers with various shapes and sizes produced with the new photolithographic technology developed by Professor Kim
2015.04.06 View 9644 -
Polymers with Highly Improved Light-transformation Efficiency
A joint Korean research team, led by Professor Bum-Joon Kim of the Department of Chemical and Biomolecular Engineering at KAIST and Professor Young-Woo Han of the Department of Nanofusion Engineering at Pusan National University, has developed a new type of electrically-conductive polymer for solar batteries with an improved light-transformation efficiency of up to 5%. The team considers it a viable replacement for existing plastic batteries for solar power which is viewed as the energy source of the future.
Polymer solar cells have greater structural stability and heat resistance compared to fullerene organic solar cells. However, they have lower light-transformation efficiency—below 4%—compared to 10% of the latter. The low efficiency is due to the failure of blending among the polymers that compose the active layer of the cell. This phenomenon deters the formation and movement of electrons and thus lowers light-transformation efficiency.
By manipulating the structure and concentration of conductive polymers, the team was able to effectively increase the polymer blending and increase light-transformation efficiency. The team was able to maximize the efficiency up to 6% which is the highest reported ratio.
Professor Kim said, “This research demonstrates that conductive polymer plastics can be used widely for solar cells and batteries for mobile devices.”
The research findings were published in the February 18th issue of the Journal of the American Chemical Society (JACS).
Picture: Flexible Solar Cell Polymer Developed by the Research Team
2015.04.05 View 9851 -
ITTP Produces 119 Graduates from 52 Countries.
“Transparency of Costa Rica was highly improved after adopting an electronic purchase and supply system from Korea.”
So noted a public official from the technical office of the digital government in Costa Rica, Ileana Palaco, who entered the master’s program in KAIST’s Global Information and Telecommunication Technology Program (ITTP) last September.
She also said, “The electronic government of Korea is an exemplary model emulated in the establishment of the e-Government system in Central and South America. I am eager to introduce Korean IT technology and policies to the countries in the region.”
Consisting of master’s and doctoral programs designed for public officials and technical experts in emerging countries, ITTP fosters international cooperation, builds human networks, and supports domestic companies in technology transfers.
For the past twenty years, the IT industry has been the key to Korea’s development. Utilizing its advancement in the IT technology, Korea provides developing countries with the support necessary for their continuous growth in the 21st century. To that end, KAIST created ITTP which invites government officials from emerging countries with a growing IT industry.
Run by the Business and Technology Management Department of KAIST since 2006, ITTP has produced 119 graduates from 52 countries. For the past 10 years, 57 students from Africa, 45 from South East-Asia, 16 from Eastern Europe, and 7 from the Middle East were accepted to the program.
The program consists of theory-based classes which introduces the technology and IT policies of Korea and project-based classes for university-industry cooperation. In the latter, experts from professional organizations in IT such as the Electronics and Telecommunications Research Institute (ETRI), the National Information Society Agency (NIA), and Korea Telecom participate and provide information based on industry experience.
Foreign governments and international organizations have reacted positively to this program. Having recognized its excellence, the International Telecommunication Union (ITU) has supported it by sending the application information to 193 member countries. The African Development Bank (AFDB) chose ITTP as one of the Next Generation African Leadership Programs and assigned 19 public officials from Africa.
ITTP graduates have played a large role in promoting the e-Government system overseas. In In 25 cases in 2012, graduates participated as researchers in 6 cases. Thanks to the support of elite public officials from emerging countries who graduated from ITTP, Korean technology companies can bring their technology to overseas countries more effectively.
Recently, government officials from these countries have been asking for both long and short- term programs on technology and IT policies. In response, KAIST is planning to expand the program. Professor Jaejeung Rho from the Business and Technology Management Department who supervises this program said, “Allowing public officials in the field of IT all over the world to know more about Korea is very important in raising Korea’s reputation in technology and in the globe” and added that “having these officials is a boon in keeping our country’s competitive edge in the IT industry.”
Picture: About 60 people including ITTP students, the Nigerian ambassador to Korea, and President Steve Kang of KAIST joined a ceremony to raise a scholarship fund for KAIST on April 2, 2015 at Munji campus in Daejeon.
2015.04.03 View 7636 -
Professor Shim Featured with His Drone System in IEEE Spectrum
The IEEE Spectrum, a technology and science magazine published by the Institute of Electrical and Electronics Engineers (IEEE), featured an article of KAIST’s autonomous unmanned aerial vehicles (UAVs) entitled “South Korea Prepares for Drone vs. Drone Combat,” posted on April 1, 2015.
The article introduces the anti-drone defense system being developed by Professor “David” Hyunchul Shim of the Department of Aerospace Engineering at KAIST. With the goal of developing guard drones that can detect and capture unknown UAVs, the anti-drone defense system consists of reconnaissance drones, agile multi-rotor UAVs equipped with nets which are dropped to snare enemy drones, and transport UAVs to carry smaller drones.
Professor Shim currently leads KAIST’s Unmanned System Research Group (USRG, http://unmanned.kaist.ac.kr/) and Center of Field Robotics for Innovation, Exploration, aNd Defense (C-FRIEND).
For the article, please go to http://spectrum.ieee.org/automaton/robotics/aerial-robots/south-korea-drone-vs-drone.
2015.04.02 View 11347 -
Mystery in Membrane Traffic How NSF Disassembles Single SNAR Complex Solved
KAIST researchers discovered that the protein N-ethylmaleimide-sensitive factor (NSF) unravels a single SNARE complex using one round ATP turnover by tearing the complex with a single burst, contradicting a previous theory that it unwinds in a processive manner.
In 2013, James E. Rothman, Randy W. Schekman, and Thomas C. Südhof won the Nobel Prize in Physiology or Medicine for their discoveries of molecular machineries for vesicle trafficking, a major transport system in cells for maintaining cellular processes. Vesicle traffic acts as a kind of “home-delivery service” in cells. Vesicles package and deliver materials such as proteins and hormones from one cell organelle to another. Then it releases its contents by fusing with the target organelle’s membrane. One example of vesicle traffic is in neuronal communications, where neurotransmitters are released from a neuron. Some of the key proteins for vesicle traffic discovered by the Nobel Prize winners were N-ethylmaleimide-sensitive factor (NSF), alpha-soluble NSF attachment protein (α-SNAP), and soluble SNAP receptors (SNAREs).
SNARE proteins are known as the minimal machinery for membrane fusion. To induce membrane fusion, the proteins combine to form a SNARE complex in a four helical bundle, and NSF and α-SNAP disassemble the SNARE complex for reuse. In particular, NSF can bind an energy source molecule, adenosine triphosphate (ATP), and the ATP-bound NSF develops internal tension via cleavage of ATP. This process is used to exert great force on SNARE complexes, eventually pulling them apart. However, although about 30 years have passed since the Nobel Prize winners’ discovery, how NSF/α-SNAP disassembled the SNARE complex remained a mystery to scientists due to a lack in methodology.
In a recent issue of Science, published on March 27, 2015, a research team, led by Tae-Young Yoon of the Department of Physics at the Korea Advanced Institute of Science and Technology (KAIST) and Reinhard Jahn of the Department of Neurobiology of the Max-Planck-Institute for Biophysical Chemistry, reports that NSF/α-SNAP disassemble a single SNARE complex using various single-molecule biophysical methods that allow them to monitor and manipulate individual protein complexes.
“We have learned that NSF releases energy in a burst within 20 milliseconds to “tear” the SNARE complex apart in a one-step global unfolding reaction, which is immediately followed by the release of SNARE proteins,” said Yoon.
Previously, it was believed that NSF disassembled a SNARE complex by unwinding it in a processive manner. Also, largely unexplained was how many cycles of ATP hydrolysis were required and how these cycles were connected to the disassembly of the SNARE complex.
Yoon added, “From our research, we found that NSF requires hydrolysis of ATPs that were already bound before it attached to the SNAREs—which means that only one round of an ATP turnover is sufficient for SNARE complex disassembly. Moreover, this is possible because NSF pulls a SNARE complex apart by building up the energy from individual ATPs and releasing it at once, yielding a “spring-loaded” mechanism.”
NSF is a member of the ATPases associated with various cellular activities family (AAA+ ATPase), which is essential for many cellular functions such as DNA replication and protein degradation, membrane fusion, microtubule severing, peroxisome biogenesis, signal transduction, and the regulation of gene expression. This research has added valuable new insights and hints for studying AAA+ ATPase proteins, which are crucial for various living beings.
The title of the research paper is “Spring-loaded unraveling of a single SNARE complex by NSF in one round of ATP turnover.” (DOI: 10.1126/science.aaa5267)
Youtube Link: https://www.youtube.com/watch?v=FqTSYHtyHWE&feature=youtu.be
Picture 1. Working model of how NSF/α-SNAP disassemble a single SNARE complex
Picture 2. After neurotransmitter release, NSF disassembles a single SNARE complex using a single round of ATP turnover in a single burst reaction.
2015.03.28 View 9930 -
KAIST & the Classic 500 Co Sign for Mobile Healthcare Research
KAIST and The Classic 500 Co., Ltd., an elder care provider based in Seoul, signed a memorandum of understanding to expand medical services by cooperating on the research of medical services and IT on March 24, 2015.
Twenty people from the two institutions, including President Steve Kang, Dong-Hyun Bak, CEO of The Classic 500 and Mun-Sul Jeong, a former KAIST Chairman of the Board, attended the signing ceremony.
Under the agreement, the two institutions will cooperate on mobile healthcare research and the development of a telemedicine system. They will also research and develop a system to better serve society with medical services.
The Classic 500, established by Konkuk University in Korea, provides nursing care services and assisted living facilities for senior citizens.
2015.03.26 View 7872