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KAIST Develops Sodium Ion Batteries using Copper Sulfide
A KAIST research team recently developed sodium ion batteries using copper sulfide anode. This finding will contribute to advancing the commercialization of sodium ion batteries (SIBs) and reducing the production cost of any electronic products with batteries.
Professor Jong Min Yuk and Emeritus Professor Jeong Yong Lee from Department of Materials Science and Engineering succeeded in developing a new anode material suitable for use in a SIB. Compared to the existing anode materials, the copper sulfide anode was measured to exhibit 1.5 times better cyclability with projected 40% reduction in cost.
Batteries used in various applications including mobile phones are lithium ion batteries, mostly referred as Li-ion batteries or LIBs. Though they are popularly used until now, large-scale energy storage systems require much inexpensive and abundant materials. Hence, a SIB has attracted enormous attention for their advantage over a lithium counterpart.
However, one main obstacle to commercialization of SIB is the lack of suitable anodes that exhibit high capacity and the cycling stability of the battery. Hence, the research team recognized this need for a good anode material that could offer high electrical conductivity and theoretical capacity. The material was found to be copper sulfide, preferably in nanoplates, which “prefers to make an alloy with sodium and is thus promising for high capacity and long-term cyclability.”
Further analysis presented in the study reveals that copper sulfide undergoes crystallographic tuning to make a room for sodium insertion. Results indicate that the sodium ion-insertion capacity of copper sulfide is as much as 1.5 times that of lithium ions for graphite. Furthermore, a battery with this new anode material retains 90% of its original capacity for 250 charge-discharge cycles.
With the natural abundance of sodium in seawater, this development may contribute to reduction in battery costs, which can be translated into up to 30% cut in the price of various consumer electronics.
Professor Lee expressed his hope for “the production of next-generation, high-performance sodium ion batteries”.
Professor Yuk said, “These days, people are showing a great deal of interest in products related to renewable energy due to recent micro-dust issues ongoing in Korea. This study may help Korea get a head-start on renewable energy products”.
This research, led by PhD candidate Jae Yeol Park and Dr. Sung Joo Kim, was published online in Nature Communications on March 2.
Figure 1. The sodiation process of copper sulfide
2018.04.17 View 6142 -
Producing 50x More Stable Adsorbent
A KAIST research team developed a technology to increase the stability of amine-containing adsorbents by fifty times, moving one step further toward commercializing stable adsorbents that last longer.
Professor Minkee Choi from the Department of Chemical and Biomolecular Engineering and his team succeeded in developing amine-containing adsorbents that show high oxidative stability.
The capture of the greenhouse gas carbon dioxide is an active ongoing research field, and some of the latest advancements point to amine-containing adsorbents as an efficient and environment-friendly way to capture carbon dioxide. However, existing amine-containing adsorbents are known to be unstable under oxidation, which chemically breaks down the adsorbent, thereby making it difficult to rely on amine-containing adsorbents for repeated and continued use.
The researchers have discovered that the miniscule amount of iron and copper present in the amine accelerate the oxidative breakdown of the amine-containing adsorbent. Upon this discovery, they proposed the use of a chelator substance, which essentially suppresses the activation of the impurities.
The team demonstrates that the proposed method renders the adsorbent up to 50 times slower in its deactivation rate due to oxidation, compared to conventional polyethyleneimine (PEI) / silica adsorbents. Figure 1 illustrates the superior performance of this oxidation-stable amine-containing adsorbent (shown in black squares), whose carbon dioxide-capturing capacity deteriorates by only a small amount (~8%). Meanwhile, the carbon dioxide-capturing capacity of the PEI/silica adsorbent (shown in red diamonds) degrades dramatically after being exposed to oxidative aging for 30 days.
This stability under oxidation is expected to have brought amine-containing adsorbents one step closer to commercialization. As such, first author Woosung Choi describes the significance of this study as “having brought solid carbon dioxide adsorbents to commercializable standards”. In fact, Professor Choi explains that commercialization steps for his team’s carbon dioxide adsorbents are already underway. He further set forth his aim to “develop the world’s best carbon dioxide capture adsorbent”.
This research, led by the PhD candidate Woosung Choi, was published online in Nature Communications on February 20.
Figure 1. Carbon dioxide working capacity against oxidative aging time. Performance of the proposed method (black) degrades much more slowly (~50x) than that of existing methods. The novel adsorbent is thus shown to be more robust to oxidation.
2018.04.16 View 5493 -
Professor Gou Young Koh, 2018 Laureate of Ho-Am Prize
Distinguished Professor Gou Young Koh from the Graduate School of Medical Science and Engineering was appointed a 2018 laureate in medicine of the Ho-Am Prize by the Ho-Am Foundation. Professor Koh is a renowned expert in the field of tumor angiogenesis by exploring the hidden nature of capillary and lymphatic vessels in human organs.
He was recognized for demonstrating the effective reduction of tumor progression and metastasis via tumor vessel normalization. This counterintuitive study result is regarded as a stepping stone for a drug discovery to prevent microvascular diseases.
Besides Professor Koh, Professor Hee Oh from Yale University (Science), Professor Nam-Gyu Park from Sungkyunkwan University (Engineering), Opera Singer Kwangchul Youn (The Arts) and Sister Carla Kang (Community Service) received awards.
The Ho-Am Prize is presented to individuals who have contributed to academics, the arts, and social development, or furthered the welfare of humanity, and commemorates the noble spirit of public service espoused by the late Chairman Byung-chull Lee, who used the pen name Ho-Am.
It was established in 1990 by Kun-Hee Lee, the chairman of Samsung. Awards have been presented to 143 individuals worth a total of 24.4 billion KRW.
2018.04.11 View 7298 -
Formation of Burning Ice in Oceanic Clay Rich Sediment Disclosed
(from left: Professor Tae-Hyuk Kwon and PhD candidate Taehyung Park) A KAIST research team has identified the formation of natural gas hydrates, so-called flammable ice, formed in oceans.
Professor Tae-Hyuk Kwon from the Department of Civil & Environmental Engineering and his team found that clay minerals in oceanic clay-rich sedimentary deposits promote formation of gas hydrates and proposed the principle of gas hydrate formation in the clayey sedimentary layers.
Gas hydrates are ice-like crystalline structures composed of hydrogen-bonded water molecules encapsulating gas molecules. They are also known as burning ice. Their deposits are so huge that they gain attention for alternative energy.
Conventionally, it was believed that formation of gas hydrates is limited in clay sedimentary deposits; however, unexpected abundance of natural gas hydrates in oceanic clay-rich sedimentary deposits raised the issue of how they formed.
The surfaces of natural clay minerals are negatively charged and, thus, unavoidably generate physicochemical interactions between clay and water. Such clay-water interactions have a critical role in the occurrence of natural gas hydrates in clay-rich sedimentary formations.
However, there has been experimental difficulty in analyzing hydrate formation because of the cations contained in clay particles, which balance the clay surface charges. Therefore, clay particles inevitably release the cations when mixed with water, which complicates the interpretation of experimental results.
To overcome this limitation, the team polarized water molecules with an electric field and monitored the induction times of water molecules forming gas hydrates.
They found that the 10 kV/m of electric field promoted gas hydrate nucleation under certain conditions rather than slowing it down, due to the partial breakage of the hydrogen bonded water clusters and the lowered thermal energy of water molecules.
Professor Kwon said, “Through this research, we gained better insight into the origin of gas hydrates occurrence in clay-rich sedimentary deposits. In the near future, we will soon be able to commercially produce methane gas from natural gas hydrate deposits.”
This research, led by PhD candidate Taehyung Park, was published online in Environmental Science and Technology on February 3. (doi: 10.1021/acs.est.7b05477)
Figure 1. Formation of gas hydrates with water molecules
Figure 2. Enhancement and inhibition of gas hydrates
2018.04.09 View 5964 -
Printed Thermo-Plasmonic Heat Patterns for Neurological Disorder Treatment
(Professor Nam and Dr. Kang, right)
A KAIST team presented a highly customizable neural stimulation method. The research team developed a technology that can print the heat pattern on a micron scale to enable the control of biological activities remotely.
The researchers integrated a precision inkjet printing technology with bio-functional thermo-plasmonic nanoparticles to achieve a ‘selective nano-photothermal neural stimulation method.’
The research team of Professor Yoonkey Nam at the Department of Bio and Brain Engineering expects this will serve as an enabling technology for personalized precision neuromodulation therapy for patients with neurological disorders.
The nano-photothermal neural stimulation method uses the thermo-plasmonic effect of metal nanoparticles to modulate the activities of neuronal networks. With the thermo-plasmonic effect, metal nanoparticles can absorb specific wavelength of illuminated light to efficiently generate localized heat. The research team discovered the inhibitory behavior of spontaneous activities of neurons upon photothermal stimulation four years ago. Since then, they have developed this technology to control hyperactive behaviors of neurons and neural circuits, which is often found in neurological disorders such as epilepsy.
In order to overcome the limitation on the spatial selectivity and resolution of the previously developed nano-photothermal method, the team adopted an inkjet printing technology to micro pattern the plasmonic nanoparticles (a few tens of microns), and successfully demonstrated that the nano-photothermal stimulation can be selectively applied according to the printed patterns.
The researchers applied a polyelectrolyte layer-by-layer coating method to printing substrates in a way to improve the pattern fidelity and achieve the uniform assembly of nanoparticles. The electrostatic attraction between the printed nanoparticles and the coated printing substrate also helped the stability of the attached nanoparticles. Because the polyelectrolyte coating is biocompatible, biological experiments including cell culture are possible with the technology developed in this work.
Using printed gold nanorod particles in a few tens of microns resolution over a several centimeters area, the researchers showed that highly complex heat patterns can be precisely formed upon light illumination according to the printing image.
Lastly, the team confirmed that the printed heat patterns can selectively and instantaneously inhibit the activities of cultured hippocampal neurons upon near-infrared light illumination. Because the printing process is applicable to thin and flexible substrates, the technology can be easily applied to implantable neurological disorder treatment devices and wearable devices. By selectively applying the heat patterns to only the desired cellular areas, customized and personalized photothermal neuromodulation therapy can be applied to patients.
“The fact that any desired heat patterns can be simply ‘printed’ anywhere broadens the applicability of this technology in many engineering fields. In bioengineering, it can be applied to neural interfaces using light and heat to modulate physiological functions. As another engineering application, for example, printed heat patterns can be used as a new concept of anti-counterfeit applications,” said the principal investigator, Yoonkey Nam at KAIST. This work, led mainly by Dr. Hongki Kang, was published in ACS Nano on February 5th 2018.
2018.04.06 View 6452 -
KAIST Develops IoT Platform for Food Safety
A research team led by the KAIST Auto-ID Labs developed a GS1 international standard-based IoTs infrastructure platform dubbed Oliot (Open Language of Internet of Things). This platform will be applied to Wanju Local Food, the nation’s largest cooperative, and will be in operation from April 5.
A total of eleven organizations participated in the development of Oliot, with KAIST as the center. This consortium is based on the GS1 international standard-based Oliot platform, which allows collecting and sharing data along the entire process of agrifood from production to processing, distribution, and consumption. It aims at increasing farm incomes and establishing a global ecosystem of domestic agriculture and stockbreeding that provides safe food.
Wanju Local Food is now the world’s first local food co-op with a traceability system from the initial stage of production planning to end sales based on GS1 international standards, which will ensure food safety.
KAIST has been sharing Oliot data in order to apply it to industries around the world. As of April 2018, approximately 900 enterprises and developers from more than 100 countries have downloaded it.
Professor Daeyoung Kim from the School of Computing, who is also Research Director of Auto-ID Labs said, “We are planning to disseminate Oliot to local food cooperatives throughout the nation. We will also cooperate with other countries, like China, Holland, and Hong Kong to create a better ecosystem for the global food industry.
“We are currently collaborating with related business to converge Oliot with AI or blockchain technology that can be applied to various services, such as healthcare and smart factories. Its tangible outcome will be revealed soon,” he added.
Auto-ID Labs are a global research consortium of six academic institutions that research and develop new technologies for advancing global commerce, partnering with GS1 (Global Standard 1), a non-profit organization that established standards for global commerce such as introducing barcodes to the retail industry. The Auto-ID Labs include MIT, University of Cambridge, Keio University, Fudan University, ETH Zurich/University of St. Gallen, and KAIST.
The consortium was supported by the Ministry of Science and ICT as well as the Institute for Information and Communications Technology Promotion for three years from 2015.
The launching of Oliot at Wanju Local Food will be held on April 5.
2018.04.03 View 7880 -
KAIST to Host FinTech Conference 2018
KAIST will be hosting a FinTech Conference with Princeton University (USA), Tsinghua University (China), and EDHEC Business School (France) in Seoul from April 12 to 13 titled State of the Art in Robo-Advising Systems: Financial Technologies for Enhanced Social Security.
The Bendhein Center for Finance and Department of Operations Research and Financial Engineering from Princeton University, Fintech Lab from Tsinghua University, and the Risk Institute from EDHEC will participate as co-hosting organizations in this conference organized by the Department of Industrial & Systems Engineering and the KAIST Center for Wealth Management Technologies.
The conference will discuss issues required for providing customized asset management to the public in terms of theory, technology, and industry.
During the conference, KAIST President Sung-Chul Shin and Chairman and CEO of the National Pension Service Sung Joo Kim will deliver welcoming addresses.
Professor John Mulvey from Princeton University, Professor Michael Dempster from Cambridge University, Professors Wei Xu and Changle Lin from Tsinghua University, Professor Lionel Martellini from EDHEC, and Professor Woo Chang Kim from KAIST are some of the invited speakers at the event.
Moreover, renowned experts in related fields will also participate in the conference, including Founder of Vanguard Group John Bogle, Jin Lee from Ant Financial, Youngsuh Cho from Shinhan Financial Group, Jung-Hwan Lee from Samsung Asset Management, and Hye Young Sung from the National Pension Service Research Institute.
Professor Kim said, “Only a small number of wealthy people can receive life-cycle customized asset management services due to the high cost structure; however, new technology derived from the Fourth Industrial Revolution can reduce the service price in an innovative manner, ultimately leading it to be popularized.”
“In an era with the poverty rate of older people reaching almost 50%.Fintech can enable individuals to manage their assets in an active manner, reinforcing social security without additional social costs in the period,” he added.
These four universities have been hosting the FinTech Conference since 2017. China will host the conference this fall, followed by France next year.
Samsung Asset Management, Alibaba Group, and Ant Financial will sponsor the conference. Anyone interested in this event can find more details at http://wmt.kaist.ac.kr/conference.html.
2018.04.02 View 6821 -
KAIST Welcomes Global Participants to AI World Cup 2018
KAIST will host the AI (Artificial Intelligence) World Cup 2018 in August, and this time it is open to the international community. AI World Cup 2018 will be a very exciting challenge for extending the limit of academic and industrial applications based on AI technology.
KAIST, after launching its AI World Cup 2017 for domestic participants, is now hosting the AI World Cup 2018 for everyone. The AI World Cup will be comprised of three events: 1) Five on five AI Soccer 2) AI Commentator and 3) AI Reporter. Winner of each category, runner-up of AI Soccer, and 2nd runner-up of AI Soccer will receive awards with cash prizes.
For AI Soccer in which AI controlled robots team up to compete, the preliminary rounds will be held in July in a league format, and the final rounds will be played on August 20-22.
For AI Commentator and AI Reporter, eight finalists will be selected for each category based on scoring criteria, and their performance will be evaluated by the judges to select the winner from each category on August 22.
During the final rounds, a variety of events will also take place at KAIST, including tutorial sessions on AI technology, a poster session where students present their research works on AI, not necessarily limited to the scope of AI Soccer, AI Commentator, and AI Reporter, and panel discussions by prominent experts in the field of AI.
Moreover, renowned experts on AI will deliver their keynote addresses. The Cyberbotics CEO Olivier Michel will address his keynote speech on the topic ‘Simulation benchmarks and competitions: a fundamental tool to foster robotics research.’
The AI World Cup was established by the College of Engineering at KAIST to show that AI technology can be further extended to sports, soccer in particular.
Professor Jong-Hwan Kim, the inventor of AI World Cup and chairman of the organizing committee said, “I hope that this event will offer a great chance to develop AI technology for use in the coming years. I wish many people can enjoy the AI World Cup 2018. I would recommend that prospective teams not worry about the technical barrier when deciding whether to participate in the games. Participants from academia and industry can test whether their code runs well in the competition simulator; this way, they will know their level of play and perhaps they can further develop their algorithms.”
“We will also broadcast the final round of AI Soccer online so that people in remote areas can also enjoy watching the games. I am looking forward to seeing all of you at the AI World Cup. Any participant with a passion to prove excellence in AI technology is welcomed with open arms,” he added.
Anyone interested in the AI World Cup 2018 can register online via aiworldcup.org . Registration starts from April 1. The deadline for registration and final code submission is June 30.
(Cubical players in the figure for domestic AI Soccer competition have been replaced with cylindrical players for more agile movements while playing)
(Opening ceremony of AI World Cup 2017)
(Trophy and prize)
(Interview of participant)
(Casters commentating on game playing)
2018.03.30 View 7161 -
Nobel Laureates Brighten the Conversation at Global Leaders Forum
Two Nobel laureates who participated in the President’s Advisory Council joined the Global Leaders Forum as plenary speakers at KAIST on March 22. The forum highlighted the 25 events which were held during the Vision Week in celebration of the Vision 2031 Declaration Ceremony on March 20.
(President of KAIST Sung-Chul Shin, making welcoming remarks)
The Global Leaders Forum, titled “Scientific Discovery and Creativity,’ brought two prominent Nobel laureates in physics and chemistry. Dr. Klaus von Klitzing from the Max-Planck Institute for Solid State Research and Dr. Kurt Wüthrich from ETH Zürich inspired more than 300 audience members, including many young scholars, at Fusion Hall.
(Dr. Klaus von Klitzing from the Max-Planck Institute for Solid State Research)
Dr. Klitzing received the prize in 1985 in recognition of his discovery of the ‘integer quantum Hall effect.’ Meanwhile Dr. Wüthrich was awarded in 2002 for ‘"the development of Nuclear Magnetic Resonance methods for the determination of protein structures in solution."
Not only did they share their journey that led to the Nobel Prize, but also disclosed their personal stories that can relate to KAIST students as they pursue their scientific careers.
Many of the questions raised pertained to ‘creativity’ and ‘failure’: what is creativity and how to improve it and what is failure and how to deal with it. Dr. Klitzing replied, “If you want to go to a new direction, ask yourself inner question: what you really want to do.”
(From left: Dr. Klaus von Klitzing and Dr. Kurt Wüthrich from ETH Zürich)
Meanwhile, Dr. Wüthrich advised to set your goal first, before you start your research. “We tend to romanticize the creativity and it can be simulated. But it hardly does. It is important to know your goal first and set it appropriately.”
“Define failure as a process to learn something new, then you can comfortably move on,” he suggested in dealing with failure. “In many cases, the great achievement sometimes happens accidentally not intentionally. Maybe, you can see one success after 100 failures in the experiments. Nobody can predict the Nobel Prize quantitatively. Set the goal, and go to international conferences frequently if possible and evaluate where you are, compared with your international peers. Then, you can modify your goal and pursue what you want to do. Foremost, just enjoy your scientific work you are working with. That’s all. There’s no secret in the Nobel Prize.”
Since artificial intelligence is taking over people’s job, there’s also the question whether the concept of creativity should be modified due to technology development.
Regarding this question, Dr. von Klitzing made a strong point that the concept of creativity stays the same. He said that creativity is something new; in that sense, computers can never be creative because they use present, existing knowledge.
There was also a surprising moment. Dr. Wűthrich, who earned a bachelor’s degree in chemistry, physics, and mathematics, revealed to the audiences that his dream used to be a football player, not a scientist. He injured his foot, which prevented him from playing soccer, and that caused him to choose another career path.
Both laureates highlighted the importance of a positive attitude for their dreams and an open mindset for their colleagues and field of study.
Dr. von Klitzing pointed out that asking new questions can be the foundation of creativity. Hence, he urged students to be open minded and try to interact with one another.
Dr. Wűthrich commented that it is the job of professors to expand the view of students and guide younger generations. For young scientists, they should keep in mind that failure is something positive and that having an optimistic attitude is crucial.
(President of KAIST Sung-Chul Shin with the panelists and Dean of KAIST Academy Tae-Eog Lee)
(Interview of Dr. Kurt Wüthrich)
2018.03.27 View 4075 -
Two Professors Receive the Asan Medical Award
(Professor Ho Min Kim and Chair Profesor Eunjoon Kim (from far right)
Chair Professor Eunjoon Kim of the Department of Biological Sciences and Professor Ho Min Kim from the Graduate School of Medical Science & Engineering won the 11th Asan Medical Award in the areas of basic medicine and young medical scholar on March 21.
The Asan Medical Award has been recognizing the most distinguished scholars in the areas of basic and clinical medicines annually since 2007.
Chair Professor Kim won the 300 million KRW award in recognition of his research in the mechanism of synaptic brain dysfunction and its relation with neural diseases.
The young medical scholar’s award recognizes a promising scholar under the age of 40. Professor Kim won the award for identifying the key protein structure and molecular mechanism controlling immunocytes and neurons. He earned a 50 million KRW prize.
2018.03.26 View 7482 -
KAIST-KU Sign MOU on 4th Industrial Technology Development
(President Shin(second from left) poses with Khalifa University President Tod Laursen after signing an MOU in the UAE on March 25. Far left is Chairman of the NST Kwangyun Wohn and far right is the UAE Minister of Educatiion Hussain Al Hammadi.)
KAIST President Sung-Chul Shin and Khalifa University Interim President Tod Laursen signed an MOU on the Fourth Industrial Technology Development on March 25 in the UAE.
They signed the MOU during the UAE-ROK Nuclear Friendship and KAIST Alumni Night at Khalifa University co-hosted by KAIST and the Korea Atomic Energy Research Institute (KAERI). The MOU will bring new opportunities to further expand bilateral cooperation in education and training in the relevant technologies called for the era of the Fourth Industrial Revolution.
More than 100 dignitaries including Chairman of National Research Council of Science and Technology (NST) in Korea Dr. Kwangyun Wohn, President of KAERI Jaejoo Ha, the UAE Minister of Education His Excellency Hussain Al Hammadi, Minister of State for Advanced Sciences Her Excellency Sarah bint Yousef Al Amiri, and His Excellency Federal Authority for Nuclear Regulation (FANR) Director General Christopher Viktorsson attended the event. In particular, a significant number of Emirati graduates of the KUSTAR-KAIST education program and many others who completed various KAIST training programs joined the event.
The Nuclear Friendship Night was celebrating the completion of the first nuclear power plant in Barakah exported by Korea. This is the first nuclear reactor in the Middle East, which is to start operation later this year. The event also coincided with Korean President Moon Jae-In’s state visit to the UAE.
KAIST and KAERI gathered distinguished leaders from the higher education and nuclear industries at the event in response to the UAE government’s top national agenda of fostering future talents and promoting the nuclear industry in order to ensure energy security.
KAIST and Khalifa University signed an initial agreement in education and research in 2009 when the governments of Korea and the UAE signed a contract to build four nuclear power plants in Barakah. Since then, the two universities have worked together closely in the areas of nuclear engineering, bio-medical engineering, robotics, mechanical engineering, chemical engineering, and materials science. With this signing on the new MOU, the partnership between the two institutions will mark the second phase of educating high-caliber human resources in science and technology of the two countries.
The KAIST Alumni Night also brought more opportunities to appreciate the achievements that the two countries have made through collaboration in education and research, mostly represented in the field of nuclear technology between KAIST and Khalifa University. During the event, KAIST graduates also shared their experiences from the education at KAIST, followed by the welcoming speeches from the UAE Minister of Education and the UAE Minister of State for Advanced Sciences.
KAIST President Shin, in his welcoming speech at the event, said, “I look forward to more students in the UAE having the opportunity to experience the world’s top-level education and global environment that KAIST offers. The collaboration with Khalifa University and the UAE is very important for building both countries’ future growth.”
KU President Laursen said, “This MOU on research cooperation focusing on technologies for the Fourth Industrial Revolution, nuclear engineering, and other technical areas will further consolidate our partnership with KAIST and support us in developing human capital suitable to take on future challenges in the science and technology sectors. We firmly believe the talent pool of experts created by this initiative will contribute to the overall economic growth of the UAE.”
2018.03.26 View 8628 -
A New Theory Improves Button Designs
Pressing a button appears effortless. People easily dismisses how challenging it is. Researchers at KAIST and Aalto University in Finland, created detailed simulations of button-pressing with the goal of producing human-like presses.
The researchers argue that the key capability of the brain is a probabilistic model. The brain learns a model that allows it to predict a suitable motor command for a button. If a press fails, it can pick a very good alternative and try it out. "Without this ability, we would have to learn to use every button like it was new," tells Professor Byungjoo Lee from the Graduate School of Culture Technology at KAIST.
After successfully activating the button, the brain can tune the motor command to be more precise, use less energy and to avoid stress or pain. "These factors together, with practice, produce the fast, minimum-effort, elegant touch people are able to perform."
The brain uses probabilistic models also to extract information optimally from the sensations that arise when the finger moves and its tip touches the button. It "enriches" the ephemeral sensations optimally based on prior experience to estimate the time the button was impacted. For example, tactile sensation from the tip of the finger a better predictor for button activation than proprioception (angle position) and visual feedback.
Best performance is achieved when all sensations are considered together. To adapt, the brain must fuse their information using prior experiences. Professor Lee explains, "We believe that the brain picks up these skills over repeated button pressings that start already as a child. What appears easy for us now has been acquired over years."
The research was triggered by admiration of our remarkable capability to adapt button-pressing. Professor Antti Oulasvirta at Aalto University said, "We push a button on a remote controller differently than a piano key. The press of a skilled user is surprisingly elegant when looked at terms of timing, reliability, and energy use. We successfully press buttons without ever knowing the inner workings of a button. It is essentially a black box to our motor system. On the other hand, we also fail to activate buttons, and some buttons are known to be worse than others."
Previous research has shown that touch buttons are worse than push-buttons, but there has not been adequate theoretical explanation.
"In the past, there has been very little attention to buttons, although we use them all the time" says Dr. Sunjun Kim from Aalto University. The new theory and simulations can be used to design better buttons.
"One exciting implication of the theory is that activating the button at the moment when the sensation is strongest will help users better rhythm their keypresses."
To test this hypothesis, the researchers created a new method for changing the way buttons are activated. The technique is called Impact Activation. Instead of activating the button at first contact, it activates it when the button cap or finger hits the floor with maximum impact.
The technique was 94% better in rapid tapping than the regular activation method for a push-button (Cherry MX switch) and 37% than a regular touchscreen button using a capacitive touch sensor. The technique can be easily deployed in touchscreens. However, regular physical keyboards do not offer the required sensing capability, although special products exist (e.g., the Wooting keyboard) on which it can be implemented.
The simulations shed new light on what happens during a button press. One problem the brain must overcome is that muscles do not activate as perfectly as we will, but every press is slightly different. Moreover, a button press is very fast, occurring within 100 milliseconds, and is too fast for correcting movement. The key to understanding button-pressing is therefore to understand how the brain adapts based on the limited sensations that are the residue of the brief press event.
The researchers also used the simulation to explain differences among physical and touchscreen-based button types. Both physical and touch buttons provide clear tactile signals from the impact of the tip with the button floor. However, with the physical button this signal is more pronounced and longer.
"Where the two button types also differ is the starting height of the finger, and this makes a difference," explains Professor Lee. "When we pull up the finger from the touchscreen, it will end up at different height every time. Its down-press cannot be as accurately controlled in time as with a push-button where the finger can rest on top of the key cap."
Three scientific articles, "Neuromechanics of a Button Press", "Impact activation improves rapid button pressing", and "Moving target selection: A cue integration model", will be presented at the CHI Conference on Human Factors in Computing Systems in Montréal, Canada, in April 2018.
2018.03.22 View 6902