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Technology to Allow Non-Magnetic Materials to Have Magnetic Properties by Professor Chan-Ho Yang
Professor Chan-Ho Yang and his research team from the Department of Physics at KAIST have developed a technology that allows non-magnetic materials to have magnetic properties or, in reverse, to remove magnetic properties from a magnet using an electric field.
Based on this research, it is expected that if magnetic-material-based data storage is developed, applications for high-speed massive data transfer will be possible.
The results of this research, with Ph.D. candidate Byung-Kwon Jang as the first author, were published online in Nature Physics on October 3.
Very small magnets exist inside of any materials. If the direction of the minuscule magnets is dis-aligned, pointing multiple directions, it is non-magnetic. If the direction is aligned in a certain direction, the material holds magnetic property just like any magnet we normally see.
Data storage capacity technology has rapidly advanced to the point where we can easily get a portable hard disk drive (HDD) with terabyte-level storage; however, the increase in storage is inevitably followed by slower data access speed for a storage device. Although HDDs are currently the most widely used data storage devices, their technical applications are limited due to their slow data access speed.
Other methods such as solid-state drives (SSDs), floating gates, and resistive switching have been developed as alternatives. Yet, they leave tracks every time data is written, and this can cause fatigue cumulative damage.
There have been many attempts to compose cells—the smallest data storage space on a storage device—with magnetic materials as that would enable faster data access speeds and remove fatigue cumulative damage. Generally, the techniques tried by researchers were to use induced magnetic fields through current flow. However, magnetic fields are very difficult to shield and can affect a large area. As a result, they alternate the magnetic property of adjacent cells. Because each cell cannot be adjusted one by one, it cannot also be arranged in a certain direction, and therefore, it is hard to change the magnetic state.
Professor Yang and his team adjusted the magnetic state by using magnetoelectric interaction to deal with this issue. Instead of using magnetic fields, magnetoelectric interaction is a method that uses an electric field to adjust the magnetic state. It has the advantage of smaller energy consumption as well.
Professor Yang's team demonstrated that cells facing random directions can be arranged in a certain direction by only inducing an electric field. In addition, the reverse was also proved to be feasible.
Until this research, most cases of previous findings were only feasible at extremely low temperatures or high temperatures, but the technology developed by the research team is practicable at room temperature by manipulating chemical pressure. It allows for a reversible magnetic state, and moreover, is non-volatile. Therefore, the results of this research are expected to provide the basis for developing next-generation information storage device.
Professor Yang said, “The changes in the electric magnetic state will be accompanied by entropy changes” and added, “Our research is expected to open new potential for future applications not only for magnetoelectric devices, but also for thermoelectric effect.”
This research has been worked on jointly with Dr. Si-Yong Choi from the Korea Institute of Materials Science, Prof. Yoon-Hee Jeong from the Pohang University of Science and Technology, Dr. Tae-Yeong Koo from the Pohang Accelerator Laboratory, Dr. Kyung-Tae Ko from the Max Planck Institute for Chemical Physics of Solids, Dr. Jun-Sik Lee and Dr. Hendrik Ohldag from the SLAC National Accelerator Laboratory of the United States, and Prof. Jan Seidel from the University of New South Wales of Australia.
The research was supported by the Mid-Career Researcher Program of the National Research Foundation of Korea, Global Research Network Support Project, Leading Research Center Support Project (Condensed Quantum Coherence Research Center), Global Frontier Project (Hybrid Interface Materials Research Group), and others.
Picture: The concept graphic for the electric-field-induced magnetic phase switching the magnetic direction
2016.11.04 View 7901 -
Next-Generation Holographic Microscope for 3D Live Cell Imaging
KAIST researchers have developed a revolutionary bio-medical imaging tool, the HT-1, to view and analyze cells, which is commercially available.
Professor YongKeun Park of the Physics Department at KAIST and his research team have developed a powerful method for 3D imaging of live cells without staining. The researchers announced the launch of their new microscopic tool, the holotomography (HT)-1, to the global marketplace through a Korean start-up that Professor Park co-founded, TomoCube (www.tomocube.com).
Professor Park is a leading researcher in the field of biophotonics and has dedicated much of his research career to working on digital holographic microscopy technology. He collaborated with TomoCube’s R&D team to develop a state-of-the-art, 2D/3D/4D holographic microscope that would allow a real-time label-free visualization of biological cells and tissues.
The HT is an optical analogy of X-ray computed tomography (CT). Both X-ray CT and HT share the same physical principle—the inverse of wave scattering. The difference is that HT uses laser illumination whereas X-ray CT uses X-ray beams. From the measurement of multiple 2D holograms of a cell, coupled with various angles of laser illuminations, the 3D refractive index (RI) distribution of the cell can be reconstructed. The reconstructed 3D RI map provides structural and chemical information of the cell including mass, morphology, protein concentration, and dynamics of the cellular membrane.
The HT enables users to quantitatively and non-invasively investigate the intrinsic properties of biological cells, for example, dry mass and protein concentration. Some of the research team’s breakthroughs that have leveraged HT’s unique and special capabilities can be found in several recent publications, including a lead article on the simultaneous 3D visualization and position tracking of optically trapped particles which was published in Optica on April 20, 2015.
Current fluorescence confocal microscopy techniques require the use of exogenous labeling agents to render high-contrast molecular information. Therefore, drawbacks include possible photo-bleaching, photo-toxicity, and interference with normal molecular activities. Immune or stem cells that need to be reinjected into the body are considered particularly difficult to employ with fluorescence microscopy.
“As one of the two currently available, high-resolution tomographic microscopes in the world, I believe that the HT-1 is the best in class regarding specifications and functionality. Users can see 3D/4D live images of cells, without fixing, coating or staining cells. Sample preparation times are reduced from a few days or hours to just a few minutes,” said Professor Park.
Two Korean hospitals, Seoul National University Hospital in Bundang and Boramae Hospital in Seoul, are using this microscope currently. The research team has also introduced the HT-1 at the Photonics West Exhibition 2016 that took place on February 16-18 in San Francisco, USA.
Professor Park added, “Our technology has set a new paradigm for cell observation under a microscope. I expect that this tomographic microscopy will be more widely used in future in various areas of pharmaceuticals, neuroscience, immunology, hematology, and cell biology.”
Figure 1: HT-1 and Its Specifications
Figure 2: 3D Images of Representative Biological Cells Taken with the HT-1
2016.03.29 View 12897 -
Ph.D. Candidate Seo Wins the Human Tech Paper Award
Hyun-Suk Seo, a doctoral student of KAIST’s Department of Electrical Engineering, received the grand prize of the “22nd Human Tech Paper Award” on February 3, 2016 from Samsung Electronics Co., Ltd.
Seo was the first to receive this prize ever since the Human Tech Paper Award was established 22 years ago. Until last year, the highest prize awarded for KAIST was a gold one.
The “Human Tech Paper Award” was established in 1994 by Samsung Electronics to discover and support outstanding scientists in the field of electrical engineering.
Entitled “Self-Gated Cardiac Cine MRI Using Phase Information,” Seo’s paper presented a technology that would reduce discomforts and inconveniences experienced by patients who take a magnetic resonance imaging (MRI).
This technology uses the speed changes of aorta and the abdominal movements of body to obtain the phase changes of magnetic resonance signals so that MRIs may be taken despite the organs’ movements.
Seo commented on his research, “I wanted to develop a technique that can make MRI a more comfortable experience. I will continue my research on this subject and hope to serve the needs of the society.”
In addition, the “Special Award,” which is given to schools, was awarded to KAIST. KAIST’s Department of Electrical Engineering has also been named the department that has received the second most awards (15 awards) this year.
Oh-Hyun Kwon, Vice President of Samsung Electronics, Steve Kang, President of KAIST, and Nak-In Seo, President of Seoul National University, participated in the event.
Picture: Hyun-Suk Seo (left), the recipient of the grand prize of the 2016 Human Tech Paper Award, and Oh-Hyun Kwon (right), Vice President of Samsung Electronics
2016.02.06 View 9118 -
Dr. Se-Jung Kim Receives the Grand Prize at the International Photo and Image Contest on Light
Dr. Se-Jung Kim of the Physics Department at KAIST received the Grand Prize at the 2015 Photo and Image Contest of the International Year of Light and Light-based Technologies.
The United Nations has designated the year 2015 as the International Year of Light and Light-based Technologies.
The Optical Society of Korea celebrated the UN’s designation by hosting an international photo and image contest on the theme of light and optics related technology.
Dr. Kim presented a photo of images taken from a liquid crystal, which was entitled “A Micro Pinwheel.” She took pictures of liquid crystal images with a polarizing microscope and then colored the pictures. The liquid crystal has self-assembled circle domain structures, and each domain can form vortex optics. Her adviser for the project is Professor Yong-Hoon Cho of the Physics Department.
Her work was exhibited during the annual conference of the Optical Society of Korea, which was held on July 13-15, 2015 at Gyeong-Ju Hwabaek International Convention Center. It will also be exhibited at the National Science Museum in Gwacheon and the Kim Dae-Jung Convention Center in Gwangju.
Picture: A Micro Pinwheel
2015.07.31 View 10120 -
Professor Sung Yong Kim Presents a Keynote Speech at the International Ocean Color Science Meeting (IOCS) 2015
Professor Sung Yong Kim of the Mechanical Engineering Department at KAIST delivered a keynote speech at the International Ocean Color Science Meeting (IOCS) 2015 held in San Francisco on June 15-18, 2015. His speech was entitled “Research and Applications Using Sub-mesoscale GOCI (Geostationary Ocean Color Imager) Data.”
The IOCS, organized by the International Ocean Color Coordinating Group (IOCCG), is a community consultation meeting providing communication and collaboration between space agencies and the ocean color community, building strong ties among international representatives of the ocean color communities, and providing a forum for discussion and the evolution of community thinking on a range of issues.
Professor Kim was recognized for his contribution towards the development of remote exploration of sub-mesoscale processes including eddies, fronts, and environmental fluid dynamics.
He also attended the 26th General Assembly of the International Union of Geodesy and Geophysics (IUGG) in Prague, the Czech Republic, on June 22, 2015 and gave a presentation on the sub-mesoscale eddies circulation research.
2015.06.12 View 9245 -
World Renowned Wireless Technology Experts Gathered in KAIST
KAIST hosted the 2015 IEEE WoW from June 5 to 6, 2015
Wireless power transfer technologies, such as wireless electric vehicles, trains and batteries, are increasingly in use. A conference, The 2015 IEEE WoW (Workshop on Wireless Power), was held in KI Building for two days starting June 5, 2015 to exchange ideas on the new trends and issues of the world wireless power technology.
The wireless power conference hosted by Institute of Electrical and Electronics Engineers (IEEE), IEEE WoW, was sponsored by its societies, PELS, IAS, IES, VTS, MAG, and PES.
This year’s conference took place in Korea for the first time and was titled “IEEE PELS Workshop on Emerging Technologies: Wireless Power.” The event was attended by around 200 experts in wireless power from 15 countries to discuss the international standards and current trends.
Keynote speakers were President Don Tan of IEEE; Professor Grant Covic of the University of Auckland; Andrew Daga, the CEO at Momentum Dynamics Corporation; Professor Ron Hui of the City University of Hong Kong; and Jung Goo Cho, the CEO of Green Power Technologies.
The forum included plenary speaking sessions on “The Futures of EV and Power Electronics,” “Development of IPT at the University of Auckland,” “Interoperable Solution for Wireless EV Charging,” “Development of IPT for Factory Automation,” “Commercialization of High Power WPT,” and “WPT: From Directional Power to Omni-directional Power.”
Notably, KAIST Professor Dong-Ho Cho, responsible for KAIST’s On-Line Electric Vehicle (OLEV) development, spoke on “The Development of Shaped Magnetic Field Systems for EVs and Trains” to introduce the KAIST OLEV bus and OLEV trains developed in cooperation with Korea Railroad Research Institute.
The Dialog Sessions on “The Futures of Wireless Electric Vehicles” were led by John M. Miller of JNJ Miller and “Road Charged EV and WPT Regulation and Standard for EV in Japan” by Yoichi Hori of University of Tokyo.
The General Chair of this year’s IEEE WoW, KAIST Professor Chun T. Rim said, “This forum serves a great assistance to the industry using wireless power technology in areas such as smartphones, home appliances, Internet of Things, and wearable devices.”
2015.05.29 View 9554 -
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 12489 -
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 13193 -
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 10365 -
Professor Mikyoung Lim Receives the MediaV Young Researcher Award
Professor Mikyoung Lim of the Department of Mathematical Sciences at KAIST received the MediaV Young Researchers Award at the International Conference on Inverse Problems and Related Topics that took place at the National Taiwan University, Taiwan, on December 15-19, 2014.
The Conference established the MediaV Young Researcher Award in 2010 to recognize distinguished scholars who are age 40 or younger and have made important contributions to the field of inverse problems. This year, two recipients were chosen for the award.
Professor Lim has focused her research on the incremental reading of incomprehensible materials’ imaging and the effect of invisibility cloaking.
The other awardee was Kui Ren, a professor at the University of Texas at Austin.
2014.12.27 View 11063 -
Ultra-high Resolution 2-dimentional Real-time Image Capture with Super Lens
Ultra-high Resolution 2-dimentional Real-time Image Capture with Super Lens
Applications to high-precision semiconductor processing or intracellular structures observation are possible.
A joint research team led by Professors Yongkeun Park and Yong-Hoon Cho from the Department of Physics, KAIST, has succeeded in capturing real-time 2D images at a resolution of 100 nm (nanometers), which was impossible with optical lens due to the diffraction limit of light until now. Its future application includes high-precision semiconductor manufacturing process or observation of intracellular structures.
This research follows the past research of the super-lens developed by Professor Park last April, using paint spray to observe images that have three times higher resolution than those discovered by conventional optical lens.
Since optical lens utilize the refraction of light, the diffraction limit, which prevents achieving focus smaller than the wavelength of light, has always been a barrier for acquiring high-resolution images. In the past, it was impossible to observe objects less than the size of 200 to 300 nm in the visible light spectrum.
In order to solve the problem of near-field extinction due to scattering of light, the research team used spray paint consisting of nano-particles massed with dense scattering materials to obtain high-resolution information.
Then, by calculating and restoring the first scattering shape of light using the time reversibility of light, the researchers were able to overcome the diffraction limit. The original position of an object to be observed is obtained by deriving the complex trajectory of the light, and reversing the time to locate the particular position of the object.
Professor Park said, “This new technology can be used as the core technology in all fields which require optical measurement and control. The existing electron microscopy cannot observe cells without destroying them, but the new technology allows us to visualize at ultra-high resolution without destruction.”
The research results were published online in the 9th edition of Physical Review Letters, a prestigious international journal in the field of physics.
2014.09.23 View 10061 -
PIBOT, a small humanoid robot flies an aircraft
The 2014 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2014) took place in Chicago, Illinois, on September 14-18, 2014.
Professor David Hyunchul Shim and his students from the Department of Aerospace Engineering, KAIST, presented a research paper entitled “A Robot-machine Interface for Full-functionality Automation Using a Humanoid” at the conference.
The robot called “PIBOT,” a pint-sized, tiny humanoid robot, uses a mixture of flight data and visuals to fly an airplane, capable of identifying and operating all of the buttons and switches in the cockpit of a normal light aircraft designed for humans.
For now, the robot is only flying a simulator, but Professor Shim expects that “PIBOT will help us have a fully automated flight experience, eventually replacing human pilots.”
The IEEE Spectrum magazine published an article on PIBOT posted online September 18, 2014. Please follow the link below for the article:
IEEE Spectrum, September 18, 2014
Tiny Humanoid Robot Learning to Fly Real Airplanes
http://spectrum.ieee.org/automaton/robotics/humanoids/tiny-humanoid-robot-learning-to-fly-real-airplanes
2014.09.23 View 13671