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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 11134 -
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 13363 -
Mutations Occurring Only in Brain Responsible for Intractable Epilepsy Identified
KAIST researchers have discovered that brain somatic mutations in MTOR gene induce intractable epilepsy and suggest a precision medicine to treat epileptic seizures.
Epilepsy is a brain disorder which afflicts more than 50 million people worldwide. Many epilepsy patients can control their symptoms through medication, but about 30% suffer from intractable epilepsy and are unable to manage the disease with drugs. Intractable epilepsy causes multiple seizures, permanent mental, physical, and developmental disabilities, and even death. Therefore, surgical removal of the affected area from the brain has been practiced as a treatment for patients with medically refractory seizures, but this too fails to provide a complete solution because only 60% of the patients who undergo surgery are rendered free of seizures.
A Korean research team led by Professor Jeong Ho Lee of the Graduate School of Medical Science and Engineering at the Korea Advanced Institute of Science and Technology (KAIST) and Professor Dong-Seok Kim of Epilepsy Research Center at Yonsei University College of Medicine has recently identified brain somatic mutations in the gene of mechanistic target of rapamycin (MTOR) as the cause of focal cortical dysplasia type II (FCDII), one of the most important and common inducers to intractable epilepsy, particularly in children. They propose a targeted therapy to lessen epileptic seizures by suppressing the activation of mTOR kinase, a signaling protein in the brain. Their research results were published online in Nature Medicine on March 23, 2015.
FCDII contributes to the abnormal developments of the cerebral cortex, ranging from cortical disruption to severe forms of cortical dyslamination, balloon cells, and dysplastic neurons. The research team studied 77 FCDII patients with intractable epilepsy who had received a surgery to remove the affected regions from the brain. The researchers used various deep sequencing technologies to conduct comparative DNA analysis of the samples obtained from the patients’ brain and blood, or saliva. They reported that about 16% of the studied patients had somatic mutations in their brain. Such mutations, however, did not take place in their blood or saliva DNA.
Professor Jeong Ho Lee of KAIST said, “This is an important finding. Unlike our previous belief that genetic mutations causing intractable epilepsy exist anywhere in the human body including blood, specific gene mutations incurred only in the brain can lead to intractable epilepsy. From our animal models, we could see how a small fraction of mutations carrying neurons in the brain could affect its entire function.”
The research team recapitulated the pathogenesis of intractable epilepsy by inducing the focal cortical expression of mutated mTOR in the mouse brain via electroporation method and observed as the mouse develop epileptic symptoms. They then treated these mice with the drug called “rapamycin” to inhibit the activity of mTOR protein and observed that it suppressed the development of epileptic seizures with cytomegalic neurons.
“Our study offers the first evidence that brain-somatic activating mutations in MTOR cause FCDII and identifies mTOR as a treatment target for intractable epilepsy,” said co-author Dr. Dong-Seok Kim, a neurosurgeon at Yonsei Medical Center with the country’s largest surgical experiences in treating patients with this condition.
The research paper is titled “Brain somatic mutations in MTOR cause focal cortical dysplasia type II leading to intractable epilepsy.” (Digital Object Identifier #: 10.1038/nm.3824)
Picture 1: A schematic image to show how to detect brain specific mutation using next-generation sequencing technology with blood-brain paired sample. Simple comparison of non-overlapping mutations between affected and unaffected tissues is able to detect brain specific mutations.
Picture 2: A schematic image to show how to generate focal cortical dysplasia mouse model. This mouse model open the new window of drug screening for seizure patients.
Picture 3: Targeted medicine can rescue the focal cortical dysplasia symptoms including cytomegalic neuron & intractable epilepsy.
2015.03.25 View 14325 -
KAIST Clinic's Dr. Joo-yeon Kim Receives Minister's Award
Dr. Joo-yeon Kim receives citation on “The Fifth Tuberculosis Prevention Day” for her contribution to campus tuberculosis outbreak prevention.
Dr. Joo-Yeon Kim, the general manager of medical services of KAIST Clinic, received an award from the Korean Ministry of Health and Welfare on March 24, 2015. The award ceremony took place during “The Fifth Tuberculosis Prevention Day,” hosted by the Ministry of Health and Welfare and supervised by the Korea Centers for Disease Control and Prevention. The event was held at Seoul Sejong Cultural Center with 300 distinguished guests in attendance including the Minister of Health and Welfare, the Committee Members of the National Assembly Health and Welfare Committee, and the Director of Korea Centers for Disease Control Prevention.
The award acknowledges Dr. Kim’s contribution to curbing a tuberculosis (TB) outbreak on KAIST’s campus in 2013. In cooperation with the Infectious Disease Prevention Committee in KAIST, Korea Centers for Disease Control and Prevention, and Yuseong Public Health Centre, Dr. Kim’s swift treatment and rigorous control of both TB and latent TB patients prevented further outbreaks.
The KAIST Clinic is the first university-affiliated clinic established in September 2010 after Neil Pappalardo, the President of MEDITEC in the US, donated $2.5 million to KAIST. It is currently running 10 medical departments including those in family medicine, stress clinic, and dentistry to provide medical care to students and staff.
Every March 24 marks the annual “Tuberculosis Prevention Day” and “World Tuberculosis Day.” The “World Tuberculosis Day” was established in 1982 to promote TB prevention and early detection. It commemorated the 100th year anniversary of the discovery of M. tuberculosis on March 24, 1883 by the German bacteriologist Robert Koch.
According to the TB Prevention Act (Article 4), Korea marks “The Tuberculosis Prevention Day” alongside the “World Tuberculosis Day” on March 24 to raise public awareness of the magnitude of the disease and the importance of prevention.
2015.03.25 View 8582 -
KAIST Develops a Credit-Card-Thick Flexible Lithium Ion Battery
Since the battery can be charged wirelessly, useful applications are expected including medical patches and smart cards.
Professor Jang Wook Choi at KAIST’s Graduate School of Energy, Environment, Water, and Sustainability (EEWS) and Dr. Jae Yong Song at the Korea Research Institute of Standards and Science jointly led research to invent a flexible lithium ion battery that is thinner than a credit card and can be charged wirelessly.
Their research findings were published online in Nano Letters on March 6, 2015. Lithium ion batteries are widely used today in various electronics including mobile devices and electronic cars. Researchers said that their work could help accelerate the development of flexible and wearable electronics.
Conventional lithium ion batteries are manufactured based on a layering technology, stacking up anodes, separating films, and cathodes like a sandwich, which makes it difficult to reduce their thickness. In addition, friction arises between layers, making the batteries impossible to bend. The coating films of electrodes easily come off, which contributes to the batteries’ poor performance.
The research team abandoned the existing production technology. Instead, they removed the separating films, layered the cathodes and anodes collinearly on a plane, and created a partition between electrodes to eliminate potential problems, such as short circuits and voltage dips, commonly present in lithium ion batteries.
After more than five thousand consecutive flexing experiments, the research team confirmed the possibility of a more flexible electrode structure while maintaining the battery performance comparable to the level of current lithium ion batteries.
Flexible batteries can be applied to integrated smart cards, cosmetic and medical patches, and skin adhesive sensors that can control a computer with voice commands or gesture as seen in the movie “Iron Man.”
Moreover, the team has successfully developed wireless-charging technology using electromagnetic induction and solar batteries.
They are currently developing a mass production process to combine this planar battery technology and printing, to ultimately create a new paradigm to print semiconductors and batteries using 3D printers.
Professor Choi said, “This new technology will contribute to diversifying patch functions as it is applicable to power various adhesive medical patches.”
Picture 1: Medical patch (left) and flexible secondary battery (right)
Picture 2: Diagram of flexible battery
Picture 3: Smart card embedding flexible battery
2015.03.24 View 12585 -
KAIST Exhibits Socially Benign Technologies
Exhibited 29 products that address the need to solve social issues such as a Braille printer
Students from the KAIST Idea Factory, a startup program for undergraduates operated by the Research Institute for Social Technology and Innovation (RISTI), hosted an exhibition presenting their research prototypes. The Idea Factory provides students with opportunities to try out new ideas and develop innovative technologies.
The exhibition was held at the Creative Learning building on campus on March 20, 2015. Students displayed 29 inventions, showcasing technologies to address important social issues. The exhibit included products and technologies developed by the students or already commercialized by small businesses such as a Braille printer, a hydrogen peroxide-oxygen respirator for vessel accidents, and an educational 3D printer. The small business exhibits included a removable additional power unit for wheelchairs, agricultural product anti-theft system, and security lighting.
KAIST also hosted a social technology innovation symposium in KAIST Institute Building on the same day. The theme of the symposium was the “Integration of Technological Innovation and Social Innovation – Social Technology Innovation.”
The key note speaker, Director Heung-Kyu Lee of RISTI, KAIST, presented a lecture on the topic, “The Meaning of Social Technology Innovation: System Change.” His talk was followed by Hyuk-Jin Choi of the Korea Social Enterprise Promotion Agency on “Social Economic Organizations of Korea and Social Technology,” and Jae-Sun Kim of The Grassroots on “Search for Social Innovation and Social Economy.”
The supervisor of the event, Director Lee said, “This exhibit focuses on technologies that could help the underprivileged. We will continue to support students’ ideas and small businesses’ endeavors to develop these technologies.”
KAIST established the Idea Factory in 2014 to assist KAIST students to commercialize creative and innovative ideas. The Idea Factory made a key contribution in commercializing the educational 3D printers last year.
Picture: A Braille Printer
2015.03.20 View 7475 -
Qualcomm Innovation Award Recognizes 20 KAIST Students
The
award provides research fellowships, worth of USD 100,000, to 20 KAIST graduate
students
With an audience of 100 people present,
KAIST held a ceremony for the Qualcomm Innovation Award 2015 at the Information
Technology Convergence building on campus on March 12, 2015.
The Qualcomm Innovation Award, established
in 2010, is a fellowship that supports innovative science and engineering master’s
and doctoral students at KAIST. Qualcomm donated USD 100,000 to KAIST, stipulating that it be used to foster a creative research environment for graduate
students.
To select the recipients, KAIST formed an award committee chaired
by Professor Soo-Young Lee of the Department of Electrical Engineering and accepted research proposals until late January.
The award committee first selected 37
proposals from 75 papers submitted and then chose the final 20 research
proposals on March 12, 2015 after presentation evaluations. The presentations had to show promise of innovation and creativity; prospective influence on wireless communications
and mobile industry; and the prospect of being implemented.
Each recipient received a USD 4,500 research
fellowship along with an opportunity to present their research findings at a
workshop where Qualcomm engineers and other distinguished individuals of the industry
will attend.
Previously, Qualcomm has donated
research fellowships to KAIST graduate students in 2011 and 2013.
2015.03.19 View 10226 -
Emeritus Professors' Social Service for Embracing Multicultural Families
Korea has become a melting pot over recent years, with many families embracing diverse nationalities, cultures, and ethnicities. A group of KAIST emeritus professors volunteered to help these multicultural families, which are often formed through international marriages, better cope with life in Korea by creating a continuing education program called “Multicultural Mother School.”
The school admitted a total of ten non-Korean mothers for its first class and held an entrance ceremony for the students on March 14, 2015, at the IFC Hope Church in Daejeon. Classes began since March 16, 2015, offering the first lecture to students remotely via the Internet.
Professor Emeritus Byung-Kyu Choi, who organized the volunteering program and is the director of the Multicultural Mother School, said, “About 5% of newborns in Korea currently come from multicultural families. It is important that we should support them to assimilate well into the Korean society. Since 60% of multicultural children have yet to enter the public school system, particularly at the elementary schools level, offering their mothers opportunities to learn more about Korea will serve a greater good.”
2015.03.14 View 6373 -
Interactions Features KAIST's Human-Computer Interaction Lab
Interactions, a bi-monthly magazine published by the Association for Computing Machinery (ACM), the largest educational and scientific computing society in the world, featured an article introducing Human-Computer Interaction (HCI) Lab at KAIST in the March/April 2015 issue (http://interactions.acm.org/archive/toc/march-april-2015).
Established in 2002, the HCI Lab (http://hcil.kaist.ac.kr/) is run by Professor Geehyuk Lee of the Computer Science Department at KAIST. The lab conducts various research projects to improve the design and operation of physical user interfaces and develops new interaction techniques for new types of computers. For the article, see the link below:
ACM Interactions, March and April 2015
Day in the Lab: Human-Computer Interaction Lab @ KAIST
http://interactions.acm.org/archive/view/march-april-2015/human-computer-interaction-lab-kaist
2015.03.02 View 10454 -
The Real Time Observation of the Birth of a Molecule
From right to left: Dr. Kyung-Hwan Kim, Professor Hyotcherl Lhee, and Jong-Gu Kim, a Ph.D. candidate
Professor Hyotcherl Lhee of the Department of Chemistry at KAIST and Japanese research teams jointly published their research results showing that they have succeeded in the direct observation of how atoms form a molecule in the online issue of Nature on February 19, 2015.
The researchers used water in which gold atoms ([Au(CN) 2- ]) are dissolved and fired X-ray pulses over the specimen in femtosecond timescales to study chemical reactions taking place among the gold atoms. They were able to examine in real time the instant process of how gold atoms bond together to become a molecule, to a trimer or tetramer state.
This direct viewing of the formation of a gold trimer complex ([Au(CN) 2- ] 3 ) will provide an opportunity to understand complex chemical and biological systems.
For details, please see the following press release that was distributed by the High Energy Accelerator Research Organization, KEK, in Japan:
Direct Observation of Bond Formations
February 18, 2015
A collaboration between researchers from KEK, the Institute for Basic Science (IBS), the Korea Advanced Institute of Science and Technology (KAIST), RIKEN, and the Japan Synchrotron Radiation Research Institute (JASRI) used the SACLA X-ray free electron laser (XFEL) facility for a real time visualization of the birth of a molecular that occurs via photoinduced formation of a chemical bonds. This achievement was published in the online version of the scientific journal “Nature” (published on 19 February 2015).
Direct “observation” of the bond making, through a chemical reaction, has been longstanding dream for chemists. However, the distance between atoms is very small, at about 100 picometer, and the bonding is completed very quickly, taking less than one picosecond (ps). Hence, previously, one could only imagine the bond formation between atoms while looking at the chemical reaction progressing in the test-tube.
In this study, the research group focused on the process of photoinduced bond formation between gold (Au) ions dissolved in water. In the ground state (S 0 state in Fig. 1) Au ions that are weakly bound to each other by an electron affinity and aligned in a bent geometry. Upon a photoexcitation, the S 0 state rapidly converts into an excited (S 1 state in Fig. 1) state where Au-Au covalent bonds are formed among Au ions aligned in a linear geometry. Subsequently, the S 1 state transforms to a triplet state (T 1 state in Fig. 1) in 1.6 ps while accompanying further contraction of Au-Au bonds by 0.1 Å. Later, the T 1 state of the trimer converts to a tetramer (tetramer state in Fig. 1) on nanosecond time scale. Finally, the Au ions returned to their original loosely interacting bent structure.
In this research, the direct observation of a very fast chemical reaction, induced by the photo-excitation, was succeeded (Fig. 2, 3). Therefore, this method is expected to be a fundamental technology for understanding the light energy conversion reaction. The research group is actively working to apply this method to the development of viable renewable energy resources, such as a photocatalysts for artificial photosynthesis using sunlight.
This research was supported by the X-ray Free Electron Laser Priority Strategy Program of the MEXT, PRESTO of the JST, and the the Innovative Areas "Artificial Photosynthesis (AnApple)" grant from the Japan Society for the Promotion of Science (JSPS).
Publication: Nature , 518 (19 February 2015)
Title: Direct observation of bond formation in solution with femtosecond X-ray scattering
Authors: K. H. Kim 1 , J. G. Kim 1 , S. Nozawa 1 , T. Sato 1 , K. Y. Oang, T. W. Kim, H. Ki, J. Jo, S. Park, C. Song, T. Sato, K. Ogawa, T. Togashi, K. Tono, M. Yabashi, T. Ishikawa, J. Kim, R. Ryoo, J. Kim, H. Ihee, S. Adachi. ※ 1: These authors contributed equally to the work.
DOI: 10.1038/nature14163
Figure 1. Structure of a gold cyano trimer complex (Au(CN) 2 - ) 3 .
Figure 2. Observed changes in the molecular structure of the gold complex
Figure 3. Schematic view of the research of photo-chemical reactions by the molecular movie
2015.02.27 View 12645 -
KAIST Develops Subminiature, Power-Efficient Air Pollution Sensing Probe
Professor Inkyu Park and his research team from the Department of Mechanical Engineering at KAIST have developed a subminiature, power-efficient air-pollution sensing probe that can be applied to mobile devices. Their research findings were published online in the January 30th issue of Scientific Reports.
As air pollution has increased, people have taken greater interest in health care. The developed technology could allow people to measure independently the air pollution level of their surrounding environments.
Previous instruments used to measure air pollution levels were bulky and consumed a lot of power. They also often produced inaccurate results when measuring air pollution in which different toxic gases were mixed. These problems could not be resolved with existing semiconductor manufacturing process.
Using local temperature field control technology, Professor Park’s team succeeded in integrating multiple heterogeneous nanomaterials and fitting them onto a small, low-power electronic chip. This microheating sensor can heat microscale regions through local hydrothermal synthesis. Because it requires a miniscale amount of nanomaterials to manufacture, the sensor is most suitable for mobile devices.
Professor Park said, “Our research will contribute to the development of convergence technology in such field as air pollution sensing probes, biosensors, electronic devices, and displays.”
The team's research was supported by the Ministry of Education and the Ministry of Science, ICT and Future Planning, Republic of Korea.
Figure 1 – The Concept of Multiple Nanomaterial Device and Numerical Simulation Results of Precursor Solutions
Figure 2 - Multiple Nanomaterial Manufactured in a Microscale Region
2015.02.27 View 10890 -
Dr. Dong-Hee Chung Honored with OYRA by Korean Physicists in America
Dr. Dong-Hee Chung, a KAIST alumnus (class of 2002) who is currently a professor of the Physics Department at the Pennsylvania State University (Penn State), received the 2015 Outstanding Young Researcher Award (OYRA) by the Association of Korean Physicists in America (AKPA).
The award ceremony was held on March 3, 2015 at AKPA’s annual conference. According to AKPA, Dr. Chung was recognized for his research achievements in the fields of the early universe, dark energy, and galaxy formation.
Dr. Chung finished both his undergraduate and graduate degrees at KAIST and received his doctorate in 2004 from the University of Texas at Austin. He was appointed a professor at Penn State in 2014.
2015.02.27 View 7302