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A Study Shows Reactive Electrolyte Additives Improve Lithium Metal Battery Performance
Stable electrode-electrolyte interfaces constructed by fluorine- and nitrogen-donating ionic additives provide an opportunity to improve high-performance lithium metal batteries
A research team showed that electrolyte additives increase the lifetime of lithium metal batteries and remarkably improve the performance of fast charging and discharging. Professor Nam-Soon Choi’s team from the Department of Chemical and Biomolecular Engineering at KAIST hierarchized the solid electrolyte interphase to make a dual-layer structure and showed groundbreaking run times for lithium metal batteries.
The team applied two electrolyte additives that have different reduction and adsorption properties to improve the functionality of the dual-layer solid electrolyte interphase. In addition, the team has confirmed that the structural stability of the nickel-rich cathode was achieved through the formation of a thin protective layer on the cathode. This study was reported in Energy Storage Materials.
Securing high-energy-density lithium metal batteries with a long lifespan and fast charging performance is vital for realizing their ubiquitous use as superior power sources for electric vehicles. Lithium metal batteries comprise a lithium metal anode that delivers 10 times higher capacity than the graphite anodes in lithium-ion batteries. Therefore, lithium metal is an indispensable anode material for realizing high-energy rechargeable batteries. However, undesirable reactions among the electrolytes with lithium metal anodes can reduce the power and this remains an impediment to achieving a longer battery lifespan. Previous studies only focused on the formation of the solid electrolyte interphase on the surface of the lithium metal anode.
The team designed a way to create a dual-layer solid electrolyte interphase to resolve the instability of the lithium metal anode by using electrolyte additives, depending on their electron accepting ability and adsorption tendencies. This hierarchical structure of the solid electrolyte interphase on the lithium metal anode has the potential to be further applied to lithium-alloy anodes, lithium storage structures, and anode-free technology to meet market expectations for electrolyte technology.
The batteries with lithium metal anodes and nickel-rich cathodes represented 80.9% of the initial capacity after 600 cycles and achieved a high Coulombic efficiency of 99.94%. These remarkable results contributed to the development of protective dual-layer solid electrolyte interphase technology for lithium metal anodes.
Professor Choi said that the research suggests a new direction for the development of electrolyte additives to regulate the unstable lithium metal anode-electrolyte interface, the biggest hurdle in research on lithium metal batteries.
She added that anode-free secondary battery technology is expected to be a game changer in the secondary battery market and electrolyte additive technology will contribute to the enhancement of anode-free secondary batteries through the stabilization of lithium metal anodes.
This research was funded by the Technology Development Program to Solve Climate Change of the National Research Foundation in Korea funded by the Ministry of Science, ICT & Future Planning and the Technology Innovation Program funded by the Ministry of Trade, Industry & Energy, and Hyundai Motor Company.
- PublicationSaehun Kim, Sung O Park, Min-Young Lee, Jeong-A Lee, Imanuel Kristanto, Tae Kyung Lee, Daeyeon Hwang, Juyoung Kim, Tae-Ung Wi, Hyun-Wook Lee, Sang Kyu Kwak, and NamSoon Choi, “Stable electrode-electrolyte interfaces constructed by fluorine- and nitrogen-donating ionic additives for high-performance lithium metal batteries,” Energy Storage Materials,45, 1-13 (2022), (doi: https://doi.org/10.1016/j.ensm.2021.10.031)
- ProfileProfessor Nam-Soon ChoiEnergy Materials LaboratoryDepartment of Chemical and Biomolecular EngineeringKAIST
2021.12.16 View 7722 -
KAIST Plans to Open a New York Campus
President Lee signs an MOU with New York-based Big Continent Inc. Chairman Hee-Nam Bae on funding the New York campus
President Kwang Hyung Lee announced a plan to open a KAIST campus in New York with funding from New York-based entrepreneur Hee-Nam Bae. President Lee and Big Continent Inc. Chairman Hee-Nam Bae signed the MOU last week for the funding to open the campus in New York.
President Lee said it will take years to open up a campus in New York in order to conform with both Korean and US legal procedures. However, during a news conference in New York following the signing of the MOU with Chairman Bae, President Lee said this is the first step toward realizing KAIST’s new vision of a ‘Global Twin Strategy’ by making New York KAIST’s newest stronghold to target both domestic and global markets.
“New York is the center of the world’s commerce, culture, and new technologies. If we want to grow big, we should go to one of the biggest cities in the world and New York is the place. I highly encourage our students and faculty go into the world and never be satisfied enjoying the top position in Korea. The next place to investigate will be Silicon Valley,” said President Lee.
“We still have many issues to resolve domestically. We need to discuss more details first with the Board of Trustees and the Korean government,” he added.
The New York campus will aim to become an enterprise-type university to help KAIST create global value. "Our goal is to make sure that Korean businesses gain competitiveness in the global market and can become listed on the NASDAQ. We plan to open majors related to AI, financial engineering, and cultural technologies. We will recruit students from both the US and KAIST to study at our New York campus.” President Lee said.
Chairman Bae, a self-made entrepreneur who immigrated to the US in 1981, also leads the Global Leadership Foundation in the US. “President Lee and I have already toured several candidate sites for the campus in the New York region and we will make a final decision on the best site to purchase,” said Chairman Bae.
Chairman Bae added that he has always dreamed of fostering young global talents who will take on global challenges with pioneering minds. He believes KAIST shares this global vision.
The New York campus will be the first KAIST campus for global students funded by someone from the private sector. This is also a major step forward for KAIST, which was founded by a six million dollar USAID loan in 1971. KAIST announced its plans to establish Kenya KAIST in 2018 with funding from the Korea Eximbank’s 95 million USD development cooperation fund loan to the Kenyan government. KAIST will provide turn-key-based education consultancy featuring curriculum design and the construction of facilities for Kenya’s first advanced science and technology institute. The campus will be located in the Konza Techno City near Nairobi and plans to open in 2023.
2021.12.13 View 7265 -
Startup Elice Donates 300 Million KRW to School of Computing
Elice hopes to create a virtuous circle that bridges the educational gap
Elice, a student startup from the School of Computing has committed to donate 300 million KRW to KAIST. Jae-Won Kim, CEO of the coding education company, established the startup with his colleagues in 2015. Since then, more than 100 companies, including 17 of Korea’s top 20 companies such as SK and LG have used Elice' digital coding platform to educate employees. More than 200,000 employees have completed the online training with completion rates over 80%.
Kim said during the donation ceremony that he hopes to fund the renovation of the School of Computing building and that he will continue to work on expanding platforms that will help make communication between educators and students more interactive. He explained, “We are making this contribution to create a virtuous circle that bridges the educational gap and improves the quality of education."
President Kwang Hyung Lee was pleased to welcome the student startup’s donation, saying, "Software talent is one of the most precious resources we should foster for the nation’s future. I am thrilled to see that a startup that was founded here on the KAIST campus has grown into a great company that provides excellent coding education for our society.”
Professor Alice Oh, who was the advisor for Kim and his colleagues when they launched the startup, joined the ceremony along with the founding members from KAIST including CPO Su-In Kim, CTO Chong-Kuk Park, and team leader Chang-Hyun Lee.
2021.12.13 View 4116 -
A Judicial Scrivener in His 90s Donates to AI Research
Dong-Myoung Kim donated 2 billion KRW to fund the Kim Jae-Chul AI Graduate School
Dong-Myong Kim, a 90-year-old resident living in Seongnam City in Kyonggido made a gift of 300 million KRW in cash and property valued at 1.7 billion KRW to fund the Kim Jae-Chul AI Graduate School. KAIST President Kwang Hyung Lee and a senior leadership team warmly received Kim during the donation ceremony on December 6 and delivered a plaque of appreciation.
Kim, a certified judicial scrivener, sent a letter regarding his intention to donate to the KAIST Development Foundation Office in October. Development foundation officers contacted him for a meeting and presented the major achievements of KAIST and new vision for the future during the meeting. After meeting with KAIST officials, Kim completed all the legal procedures for donating such as handing over the title of his property.
A Development Foundation official said that Kim was well aware of what KAIST has achieved and is doing now. “He had already searched KAIST’s website and scrutinized what we are doing now. He was clear about his intentions,” said the official.
Kim said that media news reports on the recent series of huge donations to KAIST inspired him. “I thought there was something special behind the donors’ intention to make such a decision.”
Kim said the studies on futurism he started in the 1980s led him to become interested in new technologies. “I firmly believe that KAIST will make huge contributions to the nation and our society through advances in science and technology. It is said that the joy of giving is much larger than that of receiving. I am now experiencing such immense joy. I will be even happier if KAIST can lead the nation through its AI research.”
President Kwang Hyung Lee said Kim’s letter of intention touched him deeply. He thanked Kim, saying that the entire KAIST community will make every effort to respond to Kim’s donation wishes.
2021.12.08 View 4251 -
Connecting the Dots to Find New Treatments for Breast Cancer
Systems biologists uncovered new ways of cancer cell reprogramming to treat drug-resistant cancers
Scientists at KAIST believe they may have found a way to reverse an aggressive, treatment-resistant type of breast cancer into a less dangerous kind that responds well to treatment. The study involved the use of mathematical models to untangle the complex genetic and molecular interactions that occur in the two types of breast cancer, but could be extended to find ways for treating many others. The study’s findings were published in the journal Cancer Research.
Basal-like tumours are the most aggressive type of breast cancer, with the worst prognosis. Chemotherapy is the only available treatment option, but patients experience high recurrence rates. On the other hand, luminal-A breast cancer responds well to drugs that specifically target a receptor on their cell surfaces, called estrogen receptor alpha (ERα).
KAIST systems biologist Kwang-Hyun Cho and colleagues analyzed the complex molecular and genetic interactions of basal-like and luminal-A breast cancers to find out if there might be a way to switch the former to the latter and give patients a better chance to respond to treatment.
To do this, they accessed large amounts of cancer and patient data to understand which genes and molecules are involved in the two types. They then input this data into a mathematical model that represents genes, proteins and molecules as dots and the interactions between them as lines. The model can be used to conduct simulations and see how interactions change when certain genes are turned on or off.
“There have been a tremendous number of studies trying to find therapeutic targets for treating basal-like breast cancer patients,” says Cho. “But clinical trials have failed due to the complex and dynamic nature of cancer. To overcome this issue, we looked at breast cancer cells as a complex network system and implemented a systems biological approach to unravel the underlying mechanisms that would allow us to reprogram basal-like into luminal-A breast cancer cells.”
Using this approach, followed by experimental validation on real breast cancer cells, the team found that turning off two key gene regulators, called BCL11A and HDAC1/2, switched a basal-like cancer signalling pathway into a different one used by luminal-A cancer cells. The switch reprograms the cancer cells and makes them more responsive to drugs that target ERα receptors. However, further tests will be needed to confirm that this also works in animal models and eventually humans.
“Our study demonstrates that the systems biological approach can be useful for identifying novel therapeutic targets,” says Cho.
The researchers are now expanding its breast cancer network model to include all breast cancer subtypes. Their ultimate aim is to identify more drug targets and to understand the mechanisms that could drive drug-resistant cells to turn into drug-sensitive ones.
This work was supported by the National Research Foundation of Korea, the Ministry of Science and ICT, Electronics and Telecommunications Research Institute, and the KAIST Grand Challenge 30 Project.
-Publication Sea R. Choi, Chae Young Hwang, Jonghoon Lee, and Kwang-Hyun Cho, “Network Analysis Identifies Regulators of Basal-like Breast Cancer Reprogramming and Endocrine TherapyVulnerability,” Cancer Research, November 30. (doi:10.1158/0008-5472.CAN-21-0621)
-ProfileProfessor Kwang-Hyun ChoLaboratory for Systems Biology and Bio-Inspired EngineeringDepartment of Bio and Brain EngineeringKAIST
2021.12.07 View 7548 -
A Team of Three PhD Candidates Wins the Korea Semiconductor Design Contest
“We felt a sense of responsibility to help the nation advance its semiconductor design technology”
A CMOS (complementary metal-oxide semiconductor)-based “ultra-low noise signal chip” for 6G communications designed by three PhD candidates at the KAIST School of Electrical Engineering won the Presidential Award at the 22nd Korea Semiconductor Design Contest.
The winners are PhD candidates Sun-Eui Park, Yoon-Seo Cho, and Ju-Eun Bang from the Integrated Circuits and System Lab run by Professor Jaehyouk Choi. The contest, which is hosted by the Ministry of Trade, Industry and Energy and the Korea Semiconductors Industry Association, is one of the top national semiconductor design contests for college students.
Park said the team felt a sense of responsibility to help advance semiconductor design technology in Korea when deciding to participate the contest. The team expressed deep gratitude to Professor Choi for guiding their research on 6G communications.
“Our colleagues from other labs and seniors who already graduated helped us a great deal, so we owe them a lot,” explained Park. Cho added that their hard work finally got recognized and that acknowledgement pushes her to move forward with her research. Meanwhile, Bang said she is delighted to see that many people seem to be interested in her research topic.
Research for 6G is attempting to reach 1 tera bps (Tbps), 50 times faster than 5G communications with transmission speeds of up to 20 gigabytes. In general, the wider the communication frequency band, the higher the data transmission speed. Thus, the use of frequency bands above 100 gigahertz is essential for delivering high data transmission speeds for 6G communications.
However, it remains a big challenge to make a precise benchmark signal that can be used as a carrier wave in a high frequency band. Despite the advantages of CMOS’s ultra-small and low-power design, it still has limitations at high frequency bands and its operating frequency. Thus, it was difficult to achieve a frequency band above 100 gigahertz.
To overcome these challenges, the three students introduced ultra-low noise signal generation technology that can support high-order modulation technologies. This technology is expected to contribute to increasing the price competitiveness and density of 6G communication chips that will be used in the future.
5G just got started in 2020 and still has long way to go for full commercialization. Nevertheless, many researchers have started preparing for 6G technology, targeting 2030 since a new cellular communication appears in every other decade.
Professor Choi said, “Generating ultra-high frequency signals in bands above 100 GHz with highly accurate timing is one of the key technologies for implementing 6G communication hardware. Our research is significant for the development of the world’s first semiconductor chip that will use the CMOS process to achieve noise performance of less than 80fs in a frequency band above 100 GHz.”
The team members plan to work as circuit designers in Korean semiconductor companies after graduation. “We will continue to research the development of signal generators on the topic of award-winning 6G. We would like to continue our research on high-speed circuit designs such as ultra-fast analog-to-digital converters,” Park added.
2021.11.30 View 7200 -
Scientists Develop Wireless Networks that Allow Brain Circuits to Be Controlled Remotely through the Internet
Wireless implantable devices and IoT could manipulate the brains of animals from anywhere around the world due to their minimalistic hardware, low setup cost, ease of use, and customizable versatility
A new study shows that researchers can remotely control the brain circuits of numerous animals simultaneously and independently through the internet. The scientists believe this newly developed technology can speed up brain research and various neuroscience studies to uncover basic brain functions as well as the underpinnings of various neuropsychiatric and neurological disorders.
A multidisciplinary team of researchers at KAIST, Washington University in St. Louis, and the University of Colorado, Boulder, created a wireless ecosystem with its own wireless implantable devices and Internet of Things (IoT) infrastructure to enable high-throughput neuroscience experiments over the internet. This innovative technology could enable scientists to manipulate the brains of animals from anywhere around the world. The study was published in the journal Nature Biomedical Engineering on November 25
“This novel technology is highly versatile and adaptive. It can remotely control numerous neural implants and laboratory tools in real-time or in a scheduled way without direct human interactions,” said Professor Jae-Woong Jeong of the School of Electrical Engineering at KAIST and a senior author of the study. “These wireless neural devices and equipment integrated with IoT technology have enormous potential for science and medicine.”
The wireless ecosystem only requires a mini-computer that can be purchased for under $45, which connects to the internet and communicates with wireless multifunctional brain probes or other types of conventional laboratory equipment using IoT control modules. By optimally integrating the versatility and modular construction of both unique IoT hardware and software within a single ecosystem, this wireless technology offers new applications that have not been demonstrated before by a single standalone technology. This includes, but is not limited to minimalistic hardware, global remote access, selective and scheduled experiments, customizable automation, and high-throughput scalability.
“As long as researchers have internet access, they are able to trigger, customize, stop, validate, and store the outcomes of large experiments at any time and from anywhere in the world. They can remotely perform large-scale neuroscience experiments in animals deployed in multiple countries,” said one of the lead authors, Dr. Raza Qazi, a researcher with KAIST and the University of Colorado, Boulder. “The low cost of this system allows it to be easily adopted and can further fuel innovation across many laboratories,” Dr. Qazi added.
One of the significant advantages of this IoT neurotechnology is its ability to be mass deployed across the globe due to its minimalistic hardware, low setup cost, ease of use, and customizable versatility. Scientists across the world can quickly implement this technology within their existing laboratories with minimal budget concerns to achieve globally remote access, scalable experimental automation, or both, thus potentially reducing the time needed to unravel various neuroscientific challenges such as those associated with intractable neurological conditions.
Another senior author on the study, Professor Jordan McCall from the Department of Anesthesiology and Center for Clinical Pharmacology at Washington University in St. Louis, said this technology has the potential to change how basic neuroscience studies are performed. “One of the biggest limitations when trying to understand how the mammalian brain works is that we have to study these functions in unnatural conditions. This technology brings us one step closer to performing important studies without direct human interaction with the study subjects.”
The ability to remotely schedule experiments moves toward automating these types of experiments. Dr. Kyle Parker, an instructor at Washington University in St. Louis and another lead author on the study added, “This experimental automation can potentially help us reduce the number of animals used in biomedical research by reducing the variability introduced by various experimenters. This is especially important given our moral imperative to seek research designs that enable this reduction.”
The researchers believe this wireless technology may open new opportunities for many applications including brain research, pharmaceuticals, and telemedicine to treat diseases in the brain and other organs remotely. This remote automation technology could become even more valuable when many labs need to shut down, such as during the height of the COVID-19 pandemic.
This work was supported by grants from the KAIST Global Singularity Research Program, the National Research Foundation of Korea, the United States National Institute of Health, and Oak Ridge Associated Universities.
-PublicationRaza Qazi, Kyle Parker, Choong Yeon Kim, Jordan McCall, Jae-Woong Jeong et al. “Scalable and modular wireless-network infrastructure for large-scale behavioral neuroscience,” Nature Biomedical Engineering, November 25 2021 (doi.org/10.1038/s41551-021-00814-w)
-ProfileProfessor Jae-Woong JeongBio-Integrated Electronics and Systems LabSchool of Electrical EngineeringKAIST
2021.11.29 View 12323 -
Renault 5 EV and Canoo’s Pickup Truck Win the 2021 FMOTY Awards
KAIST Future Mobility of the Year Awards recognize the most innovative concept cars of the year
The Renault 5 EV from France and a pickup truck from the US startup Canoo won the 2021 Future Mobility of the Year Awards (FMOTY) hosted by the Cho Chun Shik Graduate School of Green Transportation at KAIST. The awards ceremony was held at Renault Samsung Motors in Seoul on November 25.
KAIST began the FMOTY in 2019 to advance future car technology and stimulate growth in the industry. The award recognizes the most innovative ideas for making the most futuristic concept car and improving the technological and social value of the industry.
The awards ceremony was attended by KAIST President Kwang Hyung Lee, the dean of the Cho Chun Shik Graduate School of Green Transportation In Gwun Jang, CEO of Renault Samsung Motors Dominique Signora, and CEO of Canoo Tony Aquila. President Lee said, “The new world order will be impacted by new technology developers who envision the future. Their innovation and creative ideas will open a new world of sustainable future transportation.”
Out of the 46 concept cars revealed at global motor exhibitions between last year and the first quarter of this year, models demonstrating transport technology useful for future society and innovative service were selected in the categories of passenger cars and commercial vehicles.
Sixteen automotive journalists from 11 countries, including the chief editor of Car Magazine in Germany Georg Kacher and editorial director of BBC Top Gear Charlie Turner, participated as judges.
This year’s award for the best concept car for a passenger vehicle went to an electric vehicle, the Renault 5 EV. The compact electric car was highly regarded for its practicality and environmental friendliness. A pickup truck by Canoo, an American EV manufacturing start-up, won the award in the commercial vehicle category. The pickup features an innovative design allowing for a variety of functions topped with a competitive price and it received overwhelming support from the judges.
While Hyundai Motors swept both prizes at the awards last year and demonstrated the potential of Korean concept cars, Canoo’s win in the commercial vehicle section as a young American venture company brought attention to the changing dynamics in the automotive market. This shows that young EV start-ups can compete with existing car companies as the automotive paradigm is shifting from those with internal combustion engines to EVs.
The awards organizers said that the Cho Chun Shik Graduate School of Green Transportation will continue to hold the FMOTY to lead the fast-changing global mobility market. For more information, please visit www.fmoty.org.
2021.11.26 View 6062 -
Professor Sung-Ju Lee’s Team Wins the Best Paper and the Methods Recognition Awards at the ACM CSCW
A research team led by Professor Sung-Ju Lee at the School of Electrical Engineering won the Best Paper Award and the Methods Recognition Award from ACM CSCW (International Conference on Computer-Supported Cooperative Work and Social Computing) 2021 for their paper “Reflect, not Regret: Understanding Regretful Smartphone Use with App Feature-Level Analysis”.
Founded in 1986, CSCW has been a premier conference on HCI (Human Computer Interaction) and Social Computing. This year, 340 full papers were presented and the best paper awards are given to the top 1% papers of the submitted. Methods Recognition, which is a new award, is given “for strong examples of work that includes well developed, explained, or implemented methods, and methodological innovation.”
Hyunsung Cho (KAIST alumus and currently a PhD candidate at Carnegie Mellon University), Daeun Choi (KAIST undergraduate researcher), Donghwi Kim (KAIST PhD Candidate), Wan Ju Kang (KAIST PhD Candidate), and Professor Eun Kyoung Choe (University of Maryland and KAIST alumna) collaborated on this research.
The authors developed a tool that tracks and analyzes which features of a mobile app (e.g., Instagram’s following post, following story, recommended post, post upload, direct messaging, etc.) are in use based on a smartphone’s User Interface (UI) layout. Utilizing this novel method, the authors revealed which feature usage patterns result in regretful smartphone use.
Professor Lee said, “Although many people enjoy the benefits of smartphones, issues have emerged from the overuse of smartphones. With this feature level analysis, users can reflect on their smartphone usage based on finer grained analysis and this could contribute to digital wellbeing.”
2021.11.22 View 5775 -
Study Finds Player-Character Relationships Affected Game Satisfaction in the Last of Us Part II
Research analyzed player experiences with a polarizing game and found differences in how the players related to their characters
The action adventure game ‘The Last of Us’ was a big hit worldwide in 2014. However, its sequel, the Last of Us Part II divided opinions in the game community when it was released in 2020.
A research team from the Games and Life Lab in the Graduate School of Culture Technology at KAIST analyzed why the game players’ reviews were so polarized and found that player-character relationships influenced the game players’ satisfaction. This study, published in Frontiers in Psychology, will help developers of character-driven games foresee how different players will react to their games.
The team under Professor Young Yim Doh conducted in-depth interviews with 12 players from diverse nations, both those satisfied and dissatisfied with the game.
The team found that three elements affected the game players’ satisfaction. First, players’ satisfaction varied according to their tolerance of forced character switches. When a player is forced to switch their controlled figure in the game to another character that is introduced as the antagonist, most players initially had a negative reaction. The feeling of being forced to play in a way they didn’t want reduced their rights as a player. However, later on, some players viewed this character switch as an interesting transition and were more tolerant toward forced game play.
Second, the researchers found that the flexibility of character attachment is related to game satisfaction. Players who were unhappy about the game resisted building a relationship with the new antagonist character. Meanwhile, players who were happy about the game slowly formed an additional relationship with the new character. This led to the player feeling conflicting emotions, which satisfied players considered a meaningful experience of understanding a perspective of someone initially considered the enemy.
Lastly, the satisfaction of the play depended on how much the players could accept a changing character image in the game. Dissatisfied players found inconsistencies in the characters’ behavior and did not accept the new information about the characters. Meanwhile, satisfied players tried to understand and accept the new information and actions.
“Previous research on narrative games focused more on the game design than on the players’ experiences. To understand why reactions to the game were very different across players, we focused our research on differences in the players’ psychological experiences with the game.” said lead author and Master’s candidate Valérie Erb.
Co-author Dr. Seyeon Lee added, “This suggests that there is no one way to satisfy all players in a character-based narrative game. To satisfy a game’s players, it is important to understand the different players in the player base, target the right player group, and manage expectations accordingly.”
This research was supported by the Year 2020 Culture Technology R&D Program by the Ministry of Culture, Sports and Tourism and the Korea Creative Content Agency.
-PublicationErb V, Lee S, and Doh YY (2021) “Player-Character Relationship and Game Satisfaction in Narrative Game: Focus on Player Experience of Character Switch in The Last of Us Part II”
Frontiers in Psychology. 12:709926. (https://doi.org/10.3389/fpsyg.2021.709926)
-ProfileProfessor Young Yim DohGames and Life LabGraduate School of Culture TechnologyKAIST
2021.11.15 View 4923 -
Marien Buissonniere Awarded the 9th Grand Award for Future Strategy
Global healthcare and humanitarian activist honored by the Grand Award for Future Strategy
The Moon Soul Graduate School of Future Strategy awarded the 9th Grand Award for Future Strategy to Marine Buissonniere, an independent advisor and practitioner in the fields of global health and humanitarian action. She currently works as a senior advisor to the Prevent Epidemics team at Resolve to Save Lives. She also co-chairs Doctors Without Borders’ Transformational Investment Capacity.
Buissonniere was recognized for designing and implementing global response strategies in global strife and disaster stricken areas over the 25 years while serving as secretary general of Doctors Without Borders. She has been working with various government agencies around the world including Resolve to Save Lives to respond to the Covid-19 pandemic and preparing global future strategies for the post-pandemic era.
The Grand Award for Future Strategy recognizes individual and organization who have contributed to the nation and humanity through future research and strategies in the fields of science and technology, economy and industry, society and culture, politics and governance, and resources and environment.
The selection committee place particular emphasis on her humanitarian efforts toward North Korea. She was in charge of the task force for resuming the health project in North Korea and facilitated the North Korean program in 2002. She also played a significant role in raising awareness of North Korea’s humanitarian issues in the international community by lecturing at Columbia and Princeton.
Buissonniere said during the awards ceremony held online on November 5, “I am very grateful to receive this award from KAIST, a world’s top-flight university as well as from South Korea related to the Korean Peninsula and North Korea, where I have spent most of my life. What makes this award even more special is it is about the international medical relief activities and system innovations that I’ve devoted my life to over the last 25 years. I am going to continue this journey to help many people in difficult situations. Eventually, I would like to make it possible for those people in need to make their own future by themselves.”
2021.11.11 View 5473 -
Nanoscale Self-Assembling Salt-Crystal ‘Origami’ Balls Envelop Liquids
Mechanical engineers have devised a ‘crystal capillary origami’ technique where salt crystals spontaneously encapsulate liquid droplets
Researchers have developed a technique whereby they can spontaneously encapsulate microscopic droplets of water and oil emulsion in a tiny sphere made of salt crystals—sort of like a minute, self-constructing origami soccer ball filled with liquid. The process, which they are calling ‘crystal capillary origami,’ could be used in a range of fields from more precise drug delivery to nanoscale medical devices.The technique is described in a paper appearing in the journal Nanoscale on September 21.
Capillary action, or ‘capillarity,’ will be familiar to most people as the way that water or other liquids can move up narrow tubes or other porous materials seemingly in defiance of gravity (for example within the vascular systems of plants, or even more simply, the drawing up of paint between the hairs of a paintbrush). This effect is due to the forces of cohesion (the tendency of a liquid’s molecules to stick together), which results in surface tension, and adhesion (their tendency to stick to the surface of other substances). The strength of the capillarity depends on the chemistry of the liquid, the chemistry of the porous material, and on the other forces acting on them both. For example, a liquid with lower surface tension than water would not be able to hold up a water strider insect.
Less well known is a related phenomenon, elasto-capillarity, that takes advantage of the relationship between capillarity and the elasticity of a very tiny flat sheet of a solid material. In certain circumstances, the capillary forces can overcome the elastic bending resistance of the sheet.
This relationship can be exploited to create ‘capillary origami,’ or three-dimensional structures. When a liquid droplet is placed on the flat sheet, the latter can spontaneously encapsulate the former due to surface tension. Capillary origami can take on other forms including wrinkling, buckling, or self-folding into other shapes. The specific geometrical shape that the 3D capillary origami structure ends up taking is determined by both the chemistry of the flat sheet and that of the liquid, and by carefully designing the shape and size of the sheet.
There is one big problem with these small devices, however. “These conventional self-assembled origami structures cannot be completely spherical and will always have discontinuous boundaries, or what you might call ‘edges,’ as a result of the original two-dimensional shape of the sheet,” said Kwangseok Park, a lead researcher on the project. He added, “These edges could turn out to be future defects with the potential for failure in the face of increased stress.” Non-spherical particles are also known to be more disadvantageous than spherical particles in terms of cellular uptake.
Professor Hyoungsoo Kim from the Department of Mechanical Engineering explained, “This is why researchers have long been on the hunt for substances that could produce a fully spherical capillary origami structure.”
The authors of the study have demonstrated such an origami sphere for the first time. They showed how instead of a flat sheet, the growth of salt-crystals can perform capillary origami action in a similar manner. What they call ‘crystal capillary origami’ spontaneously constructs a smooth spherical shell capsule from these same surface tension effects, but now the spontaneous encapsulation of a liquid is determined by the elasto-capillary conditions of growing crystals.
Here, the term ‘salt’ refers to a compound of one positively charged ion and another negatively charged. Table salt, or sodium chloride, is just one example of a salt. The researchers used four other salts: calcium propionate, sodium salicylate, calcium nitrate tetrahydrate, and sodium bicarbonate to envelop a water-oil emulsion. Normally, a salt such as sodium chloride has a cubical crystal structure, but these four salts form plate-like structures as crystallites or ‘grains’ (the microscopic shape that forms when a crystal first starts to grow) instead. These plates then self-assemble into perfect spheres.
Using scanning electron microscopy and X-ray diffraction analysis, they investigated the mechanism of such formation and concluded that it was ‘Laplace pressure’ that drives the crystallite plates to cover the emulsion surface. Laplace pressure describes the pressure difference between the interior and exterior of a curved surface caused by the surface tension at the interface between the two substances, in this case between the salt water and the oil.
The researchers hope that these self-assembling nanostructures can be used for encapsulation applications in a range of sectors, from the food industry and cosmetics to drug delivery and even tiny medical devices.
-Publication
Kwangseok Park, Hyoungsoo Kim “Crystal capillary origami capsule with self-assembled nanostructure,” Nanoscale, 13(35), 14656-14665 (DOI: 10.1039/d1nr02456f)
-Profile
Professor Hyoungsoo Kim
Fluid and Interface Laboratory
http://fil.kaist.ac.kr
Department of Mechanical Engineering
KAIST
2021.11.04 View 7734