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Thermoelectric generator on glass fabric for wearable electronic devices
Wearable computers or devices have been hailed as the next generation of mobile electronic gadgets, from smart watches to smart glasses to smart pacemakers. For electronics to be worn by a user, they must be light, flexible, and equipped with a power source, which could be a portable, long-lasting battery or no battery at all but a generator. How to supply power in a stable and reliable manner is one of the most critical issues to commercialize wearable devices.
A team of KAIST researchers headed by Byung Jin Cho, a professor of electrical engineering, proposed a solution to this problem by developing a glass fabric-based thermoelectric (TE) generator that is extremely light and flexible and produces electricity from the heat of the human body. In fact, it is so flexible that the allowable bending radius of the generator is as low as 20 mm. There are no changes in performance even if the generator bends upward and downward for up to 120 cycles.
To date, two types of TE generators have been developed based either on organic or inorganic materials. The organic-based TE generators use polymers that are highly flexible and compatible with human skin, ideal for wearable electronics. The polymers, however, have a low power output. Inorganic-based TE generators produce a high electrical energy, but they are heavy, rigid, and bulky.
Professor Cho came up with a new concept and design technique to build a flexible TE generator that minimizes thermal energy loss but maximizes power output. His team synthesized liquid-like pastes of n-type (Bi2Te3) and p-type (Sb2Te3) TE materials and printed them onto a glass fabric by applying a screen printing technique. The pastes permeated through the meshes of the fabric and formed films of TE materials in a range of thickness of several hundreds of microns. As a result, hundreds of TE material dots (in combination of n and p types) were printed and well arranged on a specific area of the glass fabric.
Professor Cho explained that his TE generator has a self-sustaining structure, eliminating thick external substrates (usually made of ceramic or alumina) that hold inorganic TE materials. These substrates have taken away a great portion of thermal energy, a serious setback which causes low output power.
He also commented,
"For our case, the glass fabric itself serves as the upper and lower substrates of a TE generator, keeping the inorganic TE materials in between. This is quite a revolutionary approach to design a generator. In so doing, we were able to significantly reduce the weight of our generator (~0.13g/cm2), which is an essential element for wearable electronics."
When using KAIST's TE generator (with a size of 10 cm x 10 cm) for a wearable wristband device, it will produce around 40 mW electric power based on the temperature difference of 31 °F between human skin and the surrounding air.
Professor Cho further described about the merits of the new generator:
"Our technology presents an easy and simple way of fabricating an extremely flexible, light, and high-performance TE generator. We expect that this technology will find further applications in scale-up systems such as automobiles, factories, aircrafts, and vessels where we see abundant thermal energy being wasted."
This research result was published online in the March 14th issue of Energy & Environmental Science and was entitled "Wearable Thermoelectric Generator Fabricated on Glass Fabric."
Youtube Link: http://www.youtube.com/watch?v=BlN9lvEzCuw&feature=youtu.be
[Picture Captions]
Caption 1: The picture shows a high-performance wearable thermoelectric generator that is extremely flexible and light.
Caption 2: A thermoelectric generator developed as a wristband. The generator can be easily curved along with the shape of human body.
Caption 3: KAIST’s thermoelectric generator can be bent as many as 120 times, but it still shows the same high performance.
2014.04.21 View 19913 -
Hidden Mechanism for the Suppression of Colon Cancer Identified
Published in Cell Reports : cells at the risk of causing colorectal cancer due to genetic mutation are discharged outside the colon tissue
Korean researchers have successfully identified the cancer inhibitory mechanism of the colon tissue. The discovery of the inherent defense mechanism of the colon tissues is expected to provide understanding of the cause of colorectal cancer.
The research was led by Kwang-Hyun Cho, a professor of Bio and Brain Engineering at KAIST (corresponding author) and participated by Dr. Jehun Song (the first author), as well as Dr. Owen Sansom, David Huels, and Rachel Ridgway from the Beatson Institute for Cancer Research in the UK and Dr. Walter Kolch from Conway Institute in Ireland.
The research was funded by the Ministry of Science, ICT and Future Planning and the National Research Foundation of Korea, and its results were published in the 28th March online edition of Cell Reports under the title of “The APC network regulates the removal of mutated cells from colonic crypts.”
The organism can repair damaged tissues by itself, but genetic mutations, which may cause cancer, can occur in the process of cell division s for the repair. The rapid cell division s and toxic substances from the digestive process cause a problem especially in colon crypt that has a high probability for genetic mutation.
The research team was able to find out that the colon tissues prevent cancer by rapidly discharging carcinogenic cells with genetic mutations from the colon crypt durin ga frequent tissue repair process.
This defense mechanism, which inhibits abnormal cell division s by reducing the time mutated cells reside in the crypt, is inherent in the colon.
Extensive mathematical simulation results show that the mutated cells with enhanced Wnt signaling acquire increased adhesion in comparison to the normal cells, which therefore move rapidly toward the upper part of the crypt and are discharged more easily.
If beta-catenine, the key factor in Wnt signal transduction pathway, is not degraded due to genetic mutation, the accumulated beta-catenine activates cell proliferation and increases cell adhesion. The special environment of crypt tissue and the tendency of the cells with similar adhesion to aggregate will therefore discharge the mutated cell, hence maintaining the tissue homeostasis.
In vivo experiment with a mouse model confirms the simulation results that, in the case of abnormal crypt, the cells with high proliferation in fact move slower.
Professor Cho said, “This research has identified that multicellular organism is exquisitely designed to maintain the tissue homeostasis despite abnormal cell mutation. This also proves the systems biology research, which is a convergence of information technology and bio-technology , can discover hidden mechanisms behind complex biological phenomena.”
Crypt: Epithelium, consisting of approximately 2,000 cells, forms a colon surface in the shape of a cave.
Wnt Signaling: A signal transduction pathway involved in the proliferation and differentiation of cells that are particularly important for the embryonic development and management of adult tissue homeostasis.
2014.04.17 View 11322 -
An Electron Cloud Distribution Observed by the Scanning Seebeck Microscope
All matters are made of small particles, namely atoms. An atom is composed of a heavy nucleus and cloud-like, extremely light electrons.
Korean researchers developed an electron microscopy technique that enables the accurate observation of an electron cloud distribution at room-temperature. The achievement is comparable to the invention of the quantum tunneling microscopy technique developed 33 years ago.
Professor Yong-Hyun Kim of the Graduate School of Nanoscience and Technology at KAIST and Dr. Ho-Gi Yeo of the Korea Research Institute of Standards and Science (KRISS) developed the Scanning Seebeck Microscope (SSM). The SSM renders clear images of atoms, as well as an electron cloud distribution. This was achieved by creating a voltage difference via a temperature gradient.
The development was introduced in the online edition of Physical Review Letters (April 2014), a prestigious journal published by the American Institute of Physics.
The SSM is expected to be economically competitive as it gives high resolution images at an atomic scale even for graphene and semiconductors, both at room temperature. In addition, if the SSM is applied to thermoelectric material research, it will contribute to the development of high-efficiency thermoelectric materials.
Through numerous hypotheses and experiments, scientists now believe that there exists an electron cloud surrounding a nucleus. IBM's Scanning Tunneling Microscope (STM) was the first to observe the electron cloud and has remained as the only technique to this day. The developers of IBM microscope, Dr. Gerd Binnig and Dr. Heinrich Rohrer, were awarded the 1986 Nobel Prize in Physics.
There still remains a downside to the STM technique, however: it required high precision and extreme low temperature and vibration. The application of voltage also affects the electron cloud, resulting in a distorted image.
The KAIST research team adopted a different approach by using the Seebeck effect which refers to the voltage generation due to a temperature gradient between two materials.
The team placed an observation sample (graphene) at room temperature (37~57℃) and detected its voltage generation. This technique made it possible to observe an electron cloud at room temperature.
Furthermore, the research team investigated the theoretical quantum mechanics behind the electron cloud using the observation gained through the Seebeck effect and also obtained by simulation capability to analyze the experimental results.
The research was a joint research project between KAIST Professor Yong-Hyun Kim and KRISS researcher Dr. Ho-Gi Yeo. Eui-Seop Lee, a Ph.D. candidate of KAIST, and KRISS researcher Dr. Sang-Hui Cho also participated. The Ministry of Science, ICT, and Future Planning, the Global Frontier Initiative, and the Disruptive Convergent Technology Development Initiative funded the project in Korea.
Picture 1: Schematic Diagram of the Scanning Seebeck Microscope (SSM)
Picture 2: Electron cloud distribution observed by SSM at room temperature
Picture 3: Professor Yong-Hyun Kim
2014.04.04 View 13111 -
The First Winner of Sang Soo Lee Award in Optics and Photonics
The Optical Society of Korea and the Optical Society of America selected Mario Garavaglia, a researcher at the La Plata Optical Research Center in Argentina, as the first winner of the Sang Soo Lee Award.
Dr. Garavaglia has been selected to receive the award in recognition for his research and education in the field of optics and photonics in Argentina.
The Sang Soo Lee Award, co-established by the Optical Society of Korea and the Optical Society of America in 2012, is awarded to an individual who has made a significant impact in the field. Special considerations are made for individuals who have introduced a new field of research, helped establish a new industry, or made a great contribution to education in the field.
The award is sponsored by the late Doctor Sang Soo Lee's family, the Optical Society of Korea, and the Optical Society of America.
The late Doctor Sang Soo Lee (1925~2010) has been widely known as the 'father of optics' in Korea. He was an active educator, researcher, and writer. Dr. Lee served as the first director of the Korea Advanced Institute of Science (KAIS), the predecessor to KAIST, which was Korea's first research oriented university.
Dr. Lee also served as the 6th president of KAIST between 1989 to 1991 and was a KAIST professor of physics for 21 years. He oversaw the completion of 50 Ph.D. and 100 Master's students as well as published 230 research papers.
Philip Bucksbaum, the president of the Optical Society of America, commented,
"Garavaglia has been an example to the spirit of the Sang Soo Lee Award. The award is the recognition for his tireless efforts and commitment to the development of optics and photonics in Argentina through his teaching, research, and publications."
Jeong-Won Woo, the president of the Optical Society of Korea, said,
"The Sang Soo Lee Award is given to researchers who have consistently contributed to the development of the field. Garavaglia is a well respected researcher in Argentina, and we are truly happy with his selection."
Dr. Garavaglia established a spectroscopy, optic, and laser laboratory in Universidad Nacional de La Plata in 1966. He founded the Center for Optical Research in 1977 and served as the chief of the laboratory until 1991.
Dr. Garavaglia published over 250 research papers in the fields of classical optics, modern optics, photoemission spectroscopy, and laser spectroscopy. He has also received the Galileo Galilei Award from the International Commission for Optics in 1999.
2014.03.31 View 9894 -
KAIST Holds 'Wearable Computer Contest'
Application for ‘2014 Wearable Computer Contest’ until May 23rd
KAIST is holding the 2014 Wearable Computer Contest (WCC) sponsored by Samsung Electronics in November and is currently receiving applications until May 23rd.
Wearable Computer is a device that can be worn on body or clothing, which allows users to be connected while on the move. It is currently receiving attention as the next generation of computer industry that will replace smart phones.
The Wearable Computer Contest will be held under the topic “Smart Fashion to Simple Life” and will be divided into a designated topic contest and an idea contest.
In the “designated topic contest,” each group will compete with their prototypes based on their own ideas about a wearable computer that combines IT and fashion. A total of 15 teams that enter the finals after a document review will be provided with USD 1,400 for a prototype production, Samsung's smart IT devices, and a systematic training program.
For the “idea contest,” competitors will present their ideas for a wearable computer in a poster format. The teams qualified to continue onto the finals will be given an opportunity to create and exhibit a life-sized model.
Chairman of the Wearable Computer Contest (WCC), Professor Hoejun Yoo from the KAIST Department of Electrical Engineering said, “Wearable Computer is the major future growth industry that will lead IT industry after smart phones. I hope WCC will help nurture the future professionals in the field of wearable computer industry.”
The applications for the Wearable Computer Contest can be found on the main website (http://www.ufcom.org) until May 23rd. Both undergraduate and graduate students can participate as a team for the “designated topic contest,” and there are no qualifications required for those who enter the “idea contest.”
Last year, a total of 104 teams from universities all around Korea has participated in the Wearable Computer Contest. The finalist, team 'Jump' from Chungnam University, received the Award of the Minister of Science, ICT and Future Planning, Republic of Korea.
2014.03.28 View 9566 -
Box-shaped Pressure Vessel for LNG Developed by KAIST Research Team
Earlier today, Korean researchers successfully showcased the installation and operation of a box-shaped, high-pressure tank for the storage of liquefied natural gas in Pohang, Republic of Korea. The development was the first of its kind in the world. Pressure vessels have many applications and are widely used within the petrochemical, energy, and other industrial sectors where the transport and storage of many types of pressurized gases and fluids are essential. Pressure vessels must be designed, manufactured, installed, and operated strictly in accordance with the appropriate codes and standards since they can, in cases of leak or rupture, pose considerable health and safety hazards. Pressure vessels are normally designed in the form of a cylindrical or spherical tank. These shapes are, in principle, highly efficient in withstanding internal pressure, but rather inefficient in terms of space utilization. The tanks fit very poorly within a typically prismatic-shaped room. They cannot be packed closely together, so they do not efficiently utilize the overall space. Moreover, cylindrical or spherical tanks are not easily scalable to very large sizes because the wall thickness of the tank must increase proportionally to its overall radius. Therefore, a large pressure vessel unavoidably will have very thick walls, which are difficult and expensive to manufacture, requiring a great amount of thick-walled steel to be rolled, forged, and welded together. KAIST researchers, sponsored by POSCO, a multinational steel-making company based in Pohang, Republic of Korea, have taken a turnabout approach to construct a pressure vessel that is neither cylindrical nor spherical. Professors Pål G. Bergan and Daejun Chang and of Ocean Systems Engineering at KAIST developed a box-type, large size pressure vessel for the storage and transportation of liquids such as liquefied petroleum gas (LPG), compressed natural gas (CNG), or liquefied natural gas (LNG). The box-shaped pressure vessel has an internal, load-carrying lattice-type structure. The lattice pattern is modular in all three spatial directions, thereby effectively anchoring and balancing pressure forces on the external walls of the vessel. The modular lattice can easily be adapted to prescribed pressure levels as the overall volumetric dimensions are directly linked to the number of repetitive modules. A giant prismatic pressure vessel with a size of 20,000 m3 and a design pressure of 10 atmospheres (10 barg) can be built simply by scaling up a smaller size pressure vessel. It is interesting to note that the thickness of steel walls remains unchanged and that the weight of steel per unit storage volume goes down as the vessel size increases. Professor Chang explained the benefit of a prismatic or box-shaped pressure vessel.“If we use cylindrical pressure vessels to supply LNG fuel for a large container ship, for example, many fuel tanks will be needed. Those tanks will take up large and valuable space onboard because the cylinders have to be lined up. In our case, however, much less space is needed. The operation of a ship becomes simpler with one fuel tank rather than with many. Furthermore, our box-type pressure vessel can be designed with dimensions that precisely fit a ship. For a container ship, there may be room for a substantially higher number of containers to be loaded than when using cylindrical vessels. In a case study on a 13,000 TEU container ship, the value of the increased transport capacity tuned out USD 8.4 million for one year of operation for one ship.”The manufacturing cost of a pressure vessel has been reduced as well. Several types of special steel for cryogenic (low temperature) applications have been investigated in design and analysis studies, and this includes a new type of high-manganese steel that is being developed by POSCO. Regardless of materials, in any instance of large pressure vessels, the new lattice tank technology can offer significant savings of combined capital and operational costs. Professor Bergan was also upbeat regarding the impact of the KAIST technology innovation. “Our box-type pressure vessel represents ground-breaking research. This innovative technology will dramatically change the rules of the game for industry concerning production, transportation, and storage of fluids under high pressure and at low temperatures.”The showcased prismatic pressure vessel was a scale-down model with a volume size of 80 m3 and design pressure of 10 atmospheres. The vessel complies with the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPVC), the international standard for the appropriateness of design, fabrication, and inspection of boilers and pressure vessels. It passed the 15 pressure testing in January 2014 and received an accreditation from the ASME BPVC (ASME U2 Stamp). KAIST’s prismatic pressure vessel will be presented and displayed at Gastech 2014, the largest global conference and exhibition in the natural gas, LNG, and hydrocarbons industry. This event will take place on March 24-27 at KINTEX in Ilsan, Republic of Korea. Youtube: http://www.youtube.com/watch?v=woJwc5zisxk&list=TLGOLcI7L6_YYTn0lImPqNyeppQWRXqUt5Picture 1: The prototype of a prismatic pressure vesselPicture 2: A lattice pattern that is lined inside a prismatic pressure tankPicture 3: Above is a container ship having a box-shaped pressure vessel as a fuel tank, and below are traditional cylindrical fuel tanks.
2014.03.25 View 13427 -
Science Daily: Nanostructured Capsules Could Bring About Paints and Electronic Displays That Never Fade
A collaborative research by Professor Shin-Hyun Kim of Chemical and Bimolecular Engineering, KAIST, and his student, Tae-Min Choi, on nano-structural colors with Harvard University was published by Science Daily on March 14, 2014.
For the article, please go to:
Science Daily,
March 14, 2014
Featured Research
"Brighter inks, without pigment: Nanostructured capsules could bring about paints and electronic displays that never fade"
http://www.sciencedaily.com/releases/2014/03/140314164214.htm
2014.03.17 View 8424 -
The Korea Herald: Synthetic Biology Holds Key to Future
The Korea Herald
, a leading English newspaper in Korea, published an article on the production of gasoline by a metabolically engineered microorganism. For the article, please go to the link below:
The Korea Herald
March 14, 2014
"Synthetic biology holds key to future"
KAIST professor makes breakthrough in biorefining using E. coli’s metabolic process
http://www.koreaherald.com/view.php?ud=20140314001343
2014.03.17 View 7053 -
Professor Kyung-Wook Paik Receives the Best Presentation Award from 2014 Pan Pacific Symposium
The Surface Mount Technology Association (SMTA) hosted its 19th Annual Pan Pacific Microelectronics Symposium on February 11-13, 2014 in Hawaii.
The 2014 conference, promoting international technical exchange and extensive networking among microelectronics professionals from around the world, presented over 50 papers from 17 countries.
Professor Kyung-Wook Paik of Materials Science Engineering at KAIST received the Best Presentation Award for his paper titled, “Novel Nanofiber Anisotropic Films for Nine Pitch Assembly” at the conference.
SMTA is an international network of professionals in electronics assembly technologies, including Microsystems, emerging technologies, and related business operations.
2014.03.17 View 8543 -
Tae-Wan Kim, a doctoral candidate, receives the best paper award from ECTC
The 2014 Electronic Components and Technology Conference (ECTC) will take place on May 27-30 in Florida, USA. Tae-Wan Kim, a Ph.D. candidate at the Department of Materials Science Engineering (MSE), KAIST, will receive the Intel Best Student Paper Award at the conference.ECTC is the premier international conference that brings together the best researchers and engineers in packaging, components and microelectronic systems science, technology and education in an environment of cooperation and technical exchange. The conference is sponsored by the Components, Packaging and Manufacturing Technology (CPMT) Society of IEEE (Institute of Electrical and Electronics Engineering).The paper describes research on novel nanofiber anisotropic conductive films for ultra fine pitch electronic package application, which was written under the guidance of Professor Kyung-Wook Paik of the MSE Department. In the past ten years, two of his students have received the best paper award from ECTC.
2014.03.14 View 10377 -
Visit by Sir Paul Maxime Nurse, President of the Royal Society
Sir Paul Maxime
Nurse, who is an English geneticist and cell biologist, visited KAIST and gave
a lecture entitled The Great Ideas of
Biology on March 11, 2014.
Sir Paul was awarded the 2001 Nobel Prize in
Physiology or Medicine with Leland H. Hartwell and R. Timothy Hunt for their discoveries
of protein molecules that control the division of cells in the cell cycle.
He was Professor of Microbiology at the University
of Oxford, CEO of the Imperial Cancer Research Fund and Cancer Research UK, and
President of Rockefeller University in New York. Sir Paul is currently the President of
the Royal Society as well as Director and Chief Executive of the Francis Crick
Institute.
Founded in London in 1660, the Royal Society is composed of the world’s most distinguished scientists drawn from all areas of
science, engineering, and medicine.
Below is a summary of his lecture, The Great Ideas of Biology:
Four major ideas of biology
are the theory of genes, evolution by natural selection, the proposal that the
cell is the fundamental unit of all life, and the chemical composition of a cell.
When considering the
question “what is life?” these ideas come together. The special way cells reproduce
provides the conditions by which natural selection takes place, allowing living
organisms to evolve. The organization of chemistry within the cell provides
explanations for life’s phenomena.
In addition, an emerging idea
is the nature of biological self-organization with which living cells and organisms
process information and acquire specific forms. These great ideas have
influenced one another and changed the way we perceive biology and science
today.
2014.03.11 View 9685 -
Book Announcement: Sound Visualization and Manipulation
The movie
Gravity
won seven Oscar awards this year, one of which was for its outstanding 3D sound mixing, immersing viewers in the full experience of the troubled space expedition.
3D audio effects are generated by manipulating the sound produced by speakers, speaker-arrays, or headphones to place a virtual sound source at a desired location in 3D space such as behind, above, or below the listener's head.
Two professors from the Department of Mechanical Engineering at KAIST have recently published a book that explains two important technologies related to 3D sound effects: sound visualization and manipulation.
Professor Yang-Hann Kim, an eminent scholar in sound engineering, and Professor Jung-Woo Choi collaborated to write Sound Visualization and Manipulation (Wily 2013), which uniquely addresses the two most important problems in the field in a unified way.
The book introduces general concepts and theories and describes a number of techniques in sound visualization and manipulation, offering an interrelated approach to two very different topics: sound field visualization techniques based on microphone arrays and controlled sound field generation techniques using loudspeaker arrays.
The authors also display a solid understanding of the associated physical and mathematical concepts applied to solve the visualization and manipulation problems and provide extensive examples demonstrating the benefits and drawbacks of various applications, including beamforming and acoustic holography technology.
The book will be an excellent reference for graduate students, researchers, and professionals in acoustic engineering, as well as in audio and noise control system development.
For detailed descriptions of the book:
http://as.wiley.com/WileyCDA/WileyTitle/productCd-1118368479.html
2014.03.10 View 11854