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Omnidirectional Free Space Wireless Charging Developed
The simultaneous charging of multiple mobile devices at 0.5 meter away from the power source is now possible under the international electromagnetic field guidelines.
Mobile devices, such as smartphones and laptops, have become indispensable portable items in modern life, but one big challenge remains to fully enjoying these devices: keeping their batteries charged.
A group of researchers at KAIST has developed a wireless-power transfer (WPT) technology that allows mobile devices to be charged at any location and in any direction, even if the devices are away from the power source, just as Wi-Fi works for Internet connections. With this technology, so long as mobile users stay in a designated area where the charging is available, e.g., the Wi-Power zone, the device, without being tethered to a charger, will pick up power automatically, as needed.
The research team led by Professor Chun T. Rim of the Nuclear and Quantum Engineering Department at KAIST has made great strides in WPT development. Their WPT system is capable of charging multiple mobile devices concurrently and with unprecedented freedom in any direction, even while holding the devices in midair or a half meter away from the power source, which is a transmitter. The research result was published in the June 2015 on-line issue of IEEE Transactions on Power Electronics, which is entitled “Six Degrees of Freedom Mobile Inductive Power Transfer by Crossed Dipole Tx (Transmitter) and Rx (Receiver) Coils.”
Professor Rim’s team has successfully showcased the technology on July 7, 2015 at a lab on KAIST’s campus. They used high-frequency magnetic materials in a dipole coil structure to build a thin, flat transmitter (Tx) system shaped in a rectangle with a size of 1m2. Either 30 smartphones with a power capacity of one watt each or 5 laptops with 2.4 watts each can be simultaneously and wirelessly charged at a 50 cm distance from the transmitter with six degrees of freedom, regardless of the devices’ three-axes positions and directions. This means that the device can receive power all around the transmitter in three-dimensional space. The maximum power transfer efficiency for the laptops was 34%. The researchers said that to fabricate plane Tx and Rx coils with the six-degree-of-freedom characteristic was a bottleneck of WPT for mobile applications.
Dipole Coil Resonance System (DCRS)
The research team used the Dipole Coil Resonance System (DCRS) to induce magnetic fields, which was developed by the team in 2014 for inductive power transfer over an extended distance. The DCRS is composed of two (transmitting and receiving) magnetic dipole coils, placed in parallel, with each coil having a ferrite core and connected with a resonant capacitor. Comparing to a conventional loop coil, the dipole coil is very compact and has a less dimension. Therefore, a crossed dipole structure has 2-dimension rather than 3-dimension of a crossed loop coil structure. The DCRS has a great advantage to transfer power even when the resonance frequency changes in the range of 1% (Q factor is below 100). The ferrite cores are optimally designed to reduce the core volume by half, and their ability to transfer power is nearly unaffected by human bodies or surrounding metal objects, making DCRS ideal to transmit wireless power in emergency situations. In a test conducted in 2014, Professor Rim succeeded in transferring 209 watts of power wirelessly to the distance of five meters. (See KAIST’s press release on DCRS for details: http://www.eurekalert.org/pub_releases/2014-04/tkai-wpt041714.php.)
Greater Flexibility and Safer Charging
The research team rearranged the two dipole coils from a parallel position to cross them in order to generate rotating magnetic fields, which was embedded in the Tx’s flat platform. This has made it possible for mobile devices to receive power from any direction.
Although wireless-power technology has been applied to smartphones, it could not offer any substantial advantages over traditional wired charging because the devices still require close contact with the transmitter, a charging pad. To use the devices freely and safely, including in public spaces, the WPT technology should provide mobile users with six degrees of freedom at a distance. Until now, all wireless-charging technologies have had difficulties with the problem of short charging distance, mostly less than 10 cm, as well as charging conditions that the devices should be placed in a fixed position. For example, the Galaxy S6 could only be charged wirelessly in a fixed position, having one degree of freedom. The degree of freedom represents mobile devices’ freedom of movement in three-dimensional space.
In addition, the DCRS works at a low magnetic field environment. Based on the magnetic flux shielding technology developed by the research team, the level of magnetic flux is below the safety level of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guideline (27µT) for general public exposure to electromagnetic field (EMF).
Professor Rim said, “Our transmitter system is safe for humans and compatible with other electronic devices. We have solved three major issues of short charging distance, the dependence on charging directions, and plane coil structures of both Tx and Rx, which have blocked the commercialization of WPT.”
Currently, the research team and KAIST’s spin-off company, TESLAS, Inc., have been conducting pilot projects to apply DCRS in various places such as cafes and offices.
YouTube Link: https://www.youtube.com/watch?v=JU64pMyJioc
Demonstration of 30 Watts Range Omnidirectional Wireless-charging at a Laboratory on KAIST’s Campus
Figure 1: Wide-range omnidirectional wireless-charging system based on DCRS can charge multiple numbers of mobile devices simultaneously in a 1m3 range. The above is a transmitter, and the below is a Samsung Galaxy Note with a receiver embedded inside.
Figure 2: Demonstration of the omnidirectional wireless-charging system (clockwise from top of the left, robust charging despite the presence of metal obstacles, omnidirectional charging, long distance charging, and multiple devices charging)
2015.07.08 View 16029 -
Experts Gather to Develop a Korean Supercomputer on KAIST Campus
KAIST hosted an inauguration ceremony for the Super-Capacity Computing Advancement Forum on July 2, 2015, to increase Korea's national computing capacity. It represents a gathering consisting of experts drawn across industry, university, and institutes in super-capacity computing.
More than ten experts from the university, including President Steve Kang and Professor Oh-Joon Kwon of the Department of Aerospace Engineering, attended the ceremony. This forum was created to secure a competitive edge in the global market by establishing a long-term strategy for the development of super computers.
The recent rise of new service industries, such as voice recognition, artificial intelligence, and the Internet of Things, has increased the need for super-capacity computing to deal more rapidly with big data. The need is made more urgent by increased investment by leading countries in this field.
The forum will organize and operate working-level subcommittees to promote in-depth discussions on issues related to super-capacity computing systems. Open forums and public hearings will be held until October, to gather information and insights needed to advance the field.
President Steve Kang, the Chairman of the Forum, said, “The forum will have a great impact on Korea’s effort to become a world leader in super-capacity computing. We plan to debate the pros and cons of potential solutions to the Korean government, to assist them in building the nation’s competitiveness in super-capacity computing capability.”
2015.07.07 View 5795 -
The Minister of Education of Kazakhstan Visits KAIST
The Minister of Education of the Republic of Kazakhstan, Aslan Sarinzhipov, and his delegation visited KAIST on June 30, 2015.
Dr. Young-Suk Ji, the Chairman of Elsevier, an academic publishing company that publishes medical and scientific literature, arranged the visit.
The Kazakh delegation showed great interest in KAIST’s educational system and research programs during their meeting with President Steve Kang of KAIST. In particular, the delegation was most impressed by the startups and entrepreneurship programs established at the KAIST Pangyo Innovation Center.
President Kang said, “I hope the Minister’s visit will help inspire more Kazakh students to come to Korea and study at KAIST.”
Kazakhstan, located in the northern part of Central Asia, gained its independence in 1991 after the collapse of the Soviet Union. Currently, there are 22 Kazakh students studying at KAIST.
2015.07.03 View 4493 -
Professor Jae Kyu Lee Appointed the President of Association for Information Systems
Chair Professor Jae Kyu Lee of KAIST’s College of Business was appointed the President of Association for Information Systems (AIS) on July 1, 2015. Professor Lee will serve a one-year term, which will end in June 2016. With four thousand members researching information systems from 90 different nations, AIS is the largest academic society in the fields of information system and business process engineering.
Professor Lee has proposed his idea of “the Bright Internet” as the official vision of AIS. Employing this vision, AIS will create technology and systems, as well as sponsor international cooperation to solve fundamental issues of the Internet including concerns over hacking and cyber-related crimes.
The extent of damage from cyber-related crimes grows each year. Every day, 56 billion junk emails are sent to computers which are hacked and become “zombie” computers. The social cost of such crimes is estimated to be 400 billion US dollars annually.
Based on "the Bright Internet," AIS will build a preventative Internet security system by adopting ground rules that make attackers responsible for the damages from such crimes. The system will also modify technology and other systems to minimize privacy infringement while maintaining security. Finally, the Bright Internet proposes to adopt an international standard for this security system through collaboration with the International Telecommunications Union (ITU).
Professor Lee said, “The vision of the Bright Internet started from an awareness that we needed to resolve issues such as Internet addiction, indiscriminate media exposure, and verbal violence. This vision developed by the experts from all around the world will not only bring a revolution of a reliable Internet platform to a global scale but also reshape the Korean Internet platform.”
2015.07.02 View 6793 -
KAIST Professor Sung-Ju Lee Appointed a Technical Program Chair of INFOCOM
Professor Sung-Ju Lee of the Department of Computer Science at KAIST has been appointed to serve as a technical program chair of IEEE INFOCOME. The computer communication conference, started in 1982, is influential in the research fields of the Internet, wireless, and data centers.
Professor Lee is the first Korean to serve as a program chair. He has been acknowledged for his work in network communications. In the 34th conference, which will be held next year, he will take part in selecting 650 experts in the field to become members and supervise the evaluation of around 1,600 papers.
Professor Lee is the leading researcher in the field of wireless mobile network systems. He is a fellow of the Institute of Electrical and Electronics Engineers (IEEE) and served as the general chair of the 20th Association for Computing Machinery (ACM) SIGMOBILE Annual International Conference on Mobile Computing & Networking (MobiCom 2014). He is on the editorial boards of IEEE Transactions on Mobile Computing (TMC) and IEEE Internet of Things Journals.
Professor Lee said, “I hope to continue the traditions of the conference, as well as integrating research from various areas of network communication. I will strive to create a program with high technology transfer probability.”
The 34th IEEE INFOCOM will take place in San Francisco in April 2016.
2015.07.02 View 7348 -
Professor Naehyuck Jang was Appointed Technical Program Chair of the Design Automation Conference
Professor Naehyuck Jang of the Electrical Engineering Department at KAIST was appointed as the technical program chair of the Design Automation Conference (DAC). He is the first Asian to serve the conference as the chair. At next year’s conference, he will select 150 program committee members and supervise the selection process of 1,000 papers.
Founded in 1964, DAC encompasses research related to automation of semiconductor processes, which usually involve billions of transistors. More than seven thousand people and 150 companies from all around the world participate, of which only the top 20% of the submitted papers are selected. It is the most prestigious conference in the field of semiconductor automation.
The Design Automation Conference also introduces optimization and automation of design processes of systems, hardware security, automobiles, and the Internet of things. Professor Jang specializes in low power system designs. As an ACM Distinguished Scientist, Professor Jang was elected as the chairman after contributing to this year’s program committee by reforming the process of selection of papers.
Professor Jang said, “This year’s conference represents a departure, where we move from the field of traditional semiconductors to the optimization of embedded system, the Internet of things, and security. He added that “we want to create a paper selection process that can propose the future of design automation.”
The 53rd annual DAC will take place at the Austin Convention Center in Texas in June 2016.
2015.07.02 View 5908 -
3D Plasmon Antenna Capable of Focusing Light into Few Nanometers
Professors Myung-Ki Kim and Yong-Hee Lee, both of the Physics Department at KAIST, and their research teams have developed a three dimensional (3D) gap-plasmon antenna which can focus light into a space a few nanometers wide. Their research findings were published in the June 10th issue of Nano Letters.
Focusing light into a point-like space is an active research field with many applications. However, concentrating light into a smaller space than its wavelength is often hindered by diffraction. To tackle this problem, many researchers have utilized the plasmonic phenomenon of a metal where light can be confined to a greater extent by overcoming the diffraction limit.
Many researchers have focused on developing a two dimensional (2D) plasmon antenna and were able to focus a light under 5 nanometers wide. However, this 2D antenna revealed a challenge: the light disperses to the opposite end regardless of how small its beam was focused. To solve this difficulty, a 3D structure had to be employed to maximize the light's intensity.
Adopting the proximal focused-ion-beam milling technology, the KAIST research team developed a 3D four nanometer wide gap-plasmon antenna. By squeezing the photons into a 3D nano space of 4 x 10 x 10 nm3 size, the researchers were able to increase the intensity of light by 400,000 times stronger than that of the incident light. Capitalizing on the enhanced intensity of light within the antenna, they intensified the second-harmonic signal and verified that the light was focused in the nano gap by scanning cathodoluminescent images.
The researchers anticipate that this technology will improve the speed of data transfer and processing up to the level of a terahertz (one trillion times per second) and to enlarge the storage volume per unit area on hard disks by 100 times. In addition, high definition images of submolecule size can be taken with actual light, instead of with an electron microscope, while improving the semiconductor process to a smaller size of few nanometers.
Professor Kim said, “A simple yet ingenious idea has shifted the research paradigm from 2D gap-plasmon antennas to 3D antennas. This technology will see numerous applications including in the field of information technology, data storage, imaging medical science, and semiconductor processes.”
The research was sponsored by the National Research Foundation of Korea.
Figure 1: 3D Gap-Plasmon Antenna Structure and Simulation Results
Figure 2 – Constructed 3D Gap-Plasmon Antenna Structure
Figure 3 – Amplified Second Harmonic Signal Generation and Light Focused in the Nano Gap
2015.06.24 View 9683 -
KAIST Ranks 39th Among Top 50 Patent Filers in the US
The US National Academy of Inventors and Intellectual Property Owners Association have just released a list of top universities worldwide, which filed the highest number of patents in the US last year. KAIST has ranked 39th with 59 patents. A total of three institutions from Korea made the list, including KAIST (114 patents) and Seoul National University’s R&DB Foundation (57 patents). For details, see the article below:
ChicagoInno, June 22, 2015
“Three Illinois Universities Are Among the Top 50 Universities Granted YS Utility Patents”
http://chicagoinno.streetwise.co/2015/06/22/patent-filings-northwestern-illinois-uchicago-among-top-patent-filers-worldwide/
2015.06.23 View 7129 -
Professor Kyoungsik Yu Receives the Young IT Engineer Award from IEEE and IEIE of Korea
Professor Kyoungsik Yu of KAIST’s Department of Electrical Engineering is the recipient of this year’s Young IT (Information Technology) Engineer Award that was co-hosted by the Institute of Electrical and Electronics Engineers (IEEE), the Institute of Electronics Engineers of Korea (IEIE), and Haedong Science Culture Foundation in Korea. The award was presented on June 22, 2015 at The Ramada Plaza Jeju Hotel on Jeju Island, Korea.
The Young IT Engineer Award is given to emerging scientists who have made significant contributions to the advancement of technology, society, environment, and creative education.
Professor Yu's main research interests are IT, energy, and imaging through miniaturization and integration of optoelectronic devices. His contribution to academic and technological development is reflected in his publication of more than 100 papers in international journals and conferences, which were cited over 2,200 times.
Professor Yu said, “I’m honored to receive this award and am encouraged by it. I also find the award meaningful because the United Nations has designated this year as the “International Year of Light and Light-based Technologies,” the field I have been involved in as a researcher.”
In addition to Korea, the IEEE has jointly hosted and presented this award to researchers in countries such as Chile, Ecuador, Peru, Singapore, and Italy.
2015.06.22 View 10036 -
Professor Jinwoo Shin of the Electrical Engineering Department Receives the 2015 ACM SIGMETRICS Rising Star Research Award
Professor Jinwoo Shin of the Electrical Engineering Department at KAIST was selected as the recipient of the 2015 ACM SIGMETRICS Rising Star Research Award.
As a computer systems performance evaluation community, SIGMETRICS annually awards a junior researcher. He was selected as the 8th annual recipient, being the first from an Asian university.
Professor Shin was recognized for his work in theoretical analysis of stochastic queueing networks and machine learning. He said, “I would like to contribute to the expansion of computing and network theory in Korea wherein those fields are unrecognized.”
He has received numerous awards including Kennneth C. Sevcik (Best Student Paper) Award at SIGMETRICS 2009, George M. Sprowls (Best MIT CS PhD Thesis) Award 2010, Best Paper Award at MOBIHOC 2013, Best Publication Award from INFORMS Applied Probability Society 2013, and Bloomberg Scientific Research Award 2015.
2015.06.21 View 8302 -
Professor Jeong-Guon Ih Is Appointed the Vice President of the International Commission for Acoustics
Professor Jeong-Guon Ih of the Mechanical Engineering Department at KAIST has been elected to serve as the Vice President of the International Commission for Acoustics (ICA) from June 2015 to the end of 2016. The appointment was made at the meeting of the ICA Board held on June 1, 2015, in Maastricht, the Netherlands.
Professor Ih currently also chairs the Asia-Pacific Acoustics Commission.
Instituted in 1951, the ICA is an academic society that promotes international development and collaboration in all fields of acoustics including research, advancement, education, and standardization. It has a membership of 44 national acoustical societies worldwide and four observer countries.
2015.06.17 View 6080 -
KAIST and Sejong City Goverment Agree to Establish a Graduate School of Medical Science and Engineering
KAIST and the government of Sejong City will cooperate to establish a graduate school of medical science and engineering. On June 11, 2015, President Steve Kang of KAIST and Mayor Choon-Hee Lee of Sejong City signed a memorandum of understanding at the city hall of Sejong to establish the school.
Under the agreement, the two organizations will work out details to establish the graduate school in Sejong on such issues as administrative assistance, financial support, curriculum development, and the creation of an environment conducive to the growth of medical science.
President Kang said, “Once this graduate school is established, KAIST will be able to offer Korea and the world top-notch researchers in the field of medical science. I have high hopes that the school will produce high-impact research breakthroughs and lead in the advancement of interdisciplinary studies in biotechnology.”
In the picture below, President Steve Kang of KAIST (third from the left) holds the signed memorandum of understanding with Mayor Choon-Hee Lee of Sejong (fourth from the left).
2015.06.16 View 6064