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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 16972 -
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 15009 -
KAIST's Thermoelectric Generator on Glass Fabric Receives the Grand Prize at the Netexplo Forum 2015
The forum announced top ten IT innovations expected to change the world and selected the grand prize on February 4, 2014.
Established in 2007 by Martine Bidegain and Thierry Happe in partnership with the French Senate and the French Ministry for the Digital Economy, the Netexplo Observatory is an independent global organization that studies the impact of digital technology and innovation on society and business.
Every year, the Netexplo Observatory hosts an international conference, the Netexplo Forum, in Paris, France, which surveys digital innovation worldwide. The 8th forum was held in partnership with the United Nations Educational, Scientific and Cultural Organization (UNESCO) on February 4-5, 2015, at the UNESCO House in Paris.
Prior to the conference, the Netexplo Forum 2015 named the top ten most promising digital technologies that will greatly impact the world.
Among them was Professor Byung Jin Cho’s research on a wearable thermoelectric generator (http://www.eurekalert.org/pub_releases/2014-04/tkai-tgo041014.php). The generator was selected as the most innovative technology this year.
Professor Cho of KAIST’s Electrical Engineering Department developed a glass fabric-based thermoelectric generator that is extremely light and flexible and that produces electricity from the heat of the human body. This technology can be applied widely to wearable computers and mobile devices.
The full list of innovations follows below:
Wearable Thermo-Element, South Korea: The human body becomes a source of energy for mobile devices.
W.Afate 3D-printer, Togo: An environmentally friendly fablab that makes a low-cost 3D-printer from recycling electronic components.
Slack, USA: By combining email, Skype, and file-sharing and social networks, internal communication becomes much easier and simpler.
PhotoMath, Croatia: A free app that enables smartphone users to solve mathematical problems simply by scanning the mathematical texts.
Kappo, Chile: Connected cyclists produce and transmit useful data for urban planning to make the city more bike-friendly.
Branching Minds, USA: An improved learning process for students in difficulty through a personalized approach.
Baidu Kuai Sou, China: Smart chopsticks that can check food hazards.
SCio, Israel: A pocket molecular sensor with various applications and data
Rainforest Connection, USA: Fighting deforestation with recycled smartphones
Sense Ebola Followup, Nigeria: A mobile tool to help contain Ebola
For more details on the wearable thermos-element which received the 2015 Netexplo Award, please go to https://www.netexplo.org/en/intelligence/innovation/wearable-thermo-element.
Pictures 1 and 2: A high-performance wearable thermoelectric generator that is extremely flexible and light.
Picture 3: Senator Catherine Morin-Desailly (left) of the French Parliament presents the 2015 Netexplo Award to Professor Byung Jin Cho (right) on February 4, 2015 at the UNESCO House in Paris.
Credit of Loran Dhérines
Picture 4: Professor Byung Jin Cho (left) poses with Dr. Joël de Rosnay (right).
Credit of Loran Dhérines
2015.02.06 View 19103 -
A magnetic pen for smartphones adds another level of conveniences
Utilizing existing features on smartphones, the MagPen provides users with a compatible and simple input tool regardless of the type of phones they are using.
A doctoral candidate at the Korea Advanced Institute of Science and Technology (KAIST) developed a magnetically driven pen interface that works both on and around mobile devices. This interface, called the MagPen, can be used for any type of smartphones and tablet computers so long as they have magnetometers embedded in.
Advised by Professor Kwang-yun Wohn of the Graduate School of Culture Technology (GSCT) at KAIST, Sungjae Hwang, a Ph.D. student, created the MagPen in collaboration with Myung-Wook Ahn, a master"s student at the GSCT of KAIST, and Andrea Bianchi, a professor at Sungkyunkwan University.
Almost all mobile devices today provide location-based services, and magnetometers are incorporated in the integrated circuits of smartphones or tablet PCs, functioning as compasses. Taking advantage of built-in magnetometers, Hwang"s team came up with a technology that enabled an input tool for mobile devices such as a capacitive stylus pen to interact more sensitively and effectively with the devices" touch screen. Text and command entered by a stylus pen are expressed better on the screen of mobile devices than those done by human fingers.
The MagPen utilizes magnetometers equipped with smartphones, thus there is no need to build an additional sensing panel for a touchscreen as well as circuits, communication modules, or batteries for the pen. With an application installed on smartphones, it senses and analyzes the magnetic field produced by a permanent magnet embedded in a standard capacitive stylus pen.
Sungjae Hwang said, "Our technology is eco-friendly and very affordable because we are able to improve the expressiveness of the stylus pen without requiring additional hardware beyond those already installed on the current mobile devices. The technology allows smartphone users to enjoy added convenience while no wastes generated."
The MagPen detects the direction at which a stylus pen is pointing; selects colors by dragging the pen across smartphone bezel; identifies pens with different magnetic properties; recognizes pen-spinning gestures; and estimates the finger pressure applied to the pen.
Notably, with its spinning motion, the MagPen expands the scope of input gestures recognized by a stylus pen beyond its existing vocabularies of gestures and techniques such as titling, hovering, and varying pressures. The tip of the pen switches from a pointer to an eraser and vice versa when spinning. Or, it can choose the thickness of the lines drawn on a screen by spinning.
"It"s quite remarkable to see that the MagPen can understand spinning motion. It"s like the pen changes its living environment from two dimensions to three dimensions. This is the most creative characteristic of our technology," added Sungjae Hwang.
Hwang"s initial research result was first presented at the International Conference on Intelligent User Interfaces organized by the Association for Computing Machinery and held on March 19-22 in Santa Monica, the US.
In the next month of August, the research team will present a paper on the MagPen technology, entitled "MagPen: Magnetically Driven Pen Interaction On and Around Conventional Smartphones" and receive an Honorable Mention Award at the 15th International Conference on Human-Computer Interaction with Mobile Devices and Services (MobileHCI 2013) to be held in Germany.
In addition to the MagPen, Hwang and his team are conducting other projects to develop different types of magnetic gadgets (collectively called "MagGetz") that include the Magnetic Marionette, a magnetic cover for a smartphone, which offers augmented interactions with the phone, as well as magnetic widgets such as buttons and toggle interface.
Hwang has filed ten patents for the MagGetz technology.
Youtube Links: http://www.youtube.com/watch?v=NkPo2las7wc, http://www.youtube.com/watch?v=J9GtgyzoZmM
2013.07.25 View 16213