Latest Research News
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Antiviral Color Nanocoating Technology
- Virus elimination effect along with a wide range of colors achieved with a low coating amount of 1g/m2 - Expected to be utilized in various industries such as medical materials, home appliances, building materials, etc. Since the onset of COVID-19, we've become accustomed to seeing antiviral films attached to elevator buttons and public transportation handles. However, conventional antiviral films are made by mixing antiviral metal particles with polymers. Due to the manufacturing process, only a very small fraction of these metal particles is exposed on the surface. As a result, contrary to the belief that these films will protect us from viruses, the actual antiviral effect upon contact with the film surface is not significant. The Korea Institute of Science and Technology (KIST) has announced that a collaborative research team led by Dr. So-Hye Cho from the Materials Architecturing Research Center and Dr. Seung Eun Lee of the Research Animal Resources Center has developed a nanocoating technology that not only maximizes the antiviral activity of the surface, but also enables the realization of various colors. The research team has developed an effective antiviral and antibacterial surface by using the sol-gel method to form a silica coating layer on various surfaces, followed by coating the silica layer with silver (Ag) nanoparticles using an aqueous solution containing silver. In turn, silver nanoparticles limit the infectivity of viruses by binding to the proteins on the virus surface, disrupting the structure and function of the virus, and making it difficult for the virus to penetrate cells. In conventional antiviral films, antiviral functional metal particles are embedded within the thin film, making it difficult for silver to come in contact with viruses. However, the technology developed by the KIST research team showcased remarkable activity with a small amount of silver nanoparticles positioned on the thin film's surface. Experiments involving lentiviruses, developed as analogs to coronaviruses, demonstrated a virus elimination rate more than twice as fast compared to commercial films. In addition, antibacterial tests against E. coli bacteria resulted in complete eradication of the bacteria within 24 hours. The developed antiviral coating technology also has the additional advantage of providing various colors by controlling light interference through different coating layer thickness. "This metal nanoparticle coating technology demonstrates superior antiviral and antibacterial effects compared to commercial products, even with a small coating of less than 1 g/m2, so its industrialization potential is very high," said Dr. So-Hye Cho of KIST. "It can be used in various industries such as medical materials, home appliances, and building materials to help manage microorganisms and prevent infections by implementing antiviral and antibacterial effects." [Fig 1] SEM/TEM analysis of the silica layer showing well-defined silver nanoparticles on the surface. [Fig 2] Comparison of antiviral effectiveness of commercial silver nanofilms versus self-developed surfaces [Fig 3] Comparison of antibacterial effectiveness of commercial silver nanofilms versus device developed surfaces ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/ The research, which was supported by the Ministry of Science and ICT (Minister Lee Jong-ho) through the Korea Research Foundation-Nano and Materials Technology Development Project (2020M3H4A3106354), KIST Future Source Research Project (2E32511), and K-DARPA Innovative Technology Development Project, was published online in the international journal ACS Applied Materials and Interfaces (IF: 9.5, JCR(%): 7.956) on November 9, 2023. Journal : ACS Applied Materials and Interfaces Title : In Situ Metal Deposition on Perhydropolysilazane-Derived Silica for Structural Color Surfaces with Antiviral Activity Publication Date : 2023.11.09. DOI : https://doi.org/10.1021/acsami.3c12622
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- WriterDr. Cho, So-Hye
- 작성일2024.02.05
- Views61
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The cause of recent cold waves over East Asia and North America was in the mid-latitude ocean fronts
- East Asian and North American cold snap anomalies are caused by mid-latitude ocean fronts, not sea ice - Important predictor fornear-term climate change on a decadal time scale If the world is warming, why are our winters getting colder? Indeed, East Asia and North America have experienced frequent extreme weather events since the 2000s that defy average climate change projections. Many experts have blamed Arctic warming and a weakening jet stream due to declining Arctic sea ice, but climate model experiments have not adequately demonstrated their validity. The massive power outage in Texas in February 2021 was caused by an unusual cold snap, and climate models are needed to accurately predict the risk of extreme weather events in order to prevent massive socioeconomic damage. In particular, climate technology leaders have recently set the ability to predict the climate of the next decade or so as an important goal. The Korea Institute of Science and Technology (KIST) announced that senior researcher Mi-Kyung Sung of the Sustainable Environment Research Center and professor Soon-Il An of the Center for Irreversible Climate Change at Yonsei University (President Seung-hwan Seo) have jointly discovered the role of mid-latitude oceans as a source of anomalous waves that are particularly frequent in East Asia and North America, paving the way for a mid- to long-term response to winter climate change. Ocean currents have a major impact on the weather and climate of neighboring countries as they transport not only suspended and dissolved matter but also heat energy. In particular, regions where temperatures change rapidly in a narrow latitudinal band, such as the Gulf Stream in the Atlantic Ocean and the downstream region of the Kuroshio Current in the Pacific Ocean, are called "ocean fronts," and the KIST-Yonsei joint research team attributes the atmospheric wave response to the excessive accumulation of heat in these ocean fronts as the cause of the increase in extreme cold waves. From the early 2000s until recently, anomalous cold trend in East Asia coincided with the accumulation of heat near the Gulf Stream in the North Atlantic, and that in North America coincided with the intensification of heat accumulation near the Kuroshio Current. The oceanic frontal region acts as a thermostat to control the frequency of winter cold waves and anomalous high temperatures. The process of heat accumulation in oceanic frontal regions lasts from years to decades. During this time, a warming hiatus can occur in the continental regions that bucks the global warming trend. Conversely, during decades of ocean frontal cooling, continental regions appear to experience a sharp acceleration of warming. This suggests that the recent decadal cooling trend is essentially reinforced by temporary natural variability in the global climate system, and that we can expect unseasonably warm winter weather to become more prevalent as the heat buildup in the ocean front is relieved. These results are also evident in climate model experiments that vary the amount of heat accumulation near ocean fronts, showing that observations and climate model experiments are consistent in their conclusions, in contrast to conventional sea ice theory. This highlights the importance of accurately simulating ocean front variability in climate models to improve our ability to predict medium- and long-term climate change over the next decade. As global warming intensifies in the future and changes the structure of the ocean, these regional climate variations could change dramatically. Climate model experiments with increased greenhouse gases have shown that North America is likely to experience shorter and fewer warming hiatus, while East Asia is likely to experience more frequent intersections between warming hiatus and acceleration. These different continental responses are driven by the different oceanic responses of the Kuroshio Current and the Gulf Stream to global warming. "Applying the effects of ocean fronts revealed in this research to global warming climate models can improve climate change forecasts for the near future," said Dr. Mi-Kyung Sung of KIST. "It will provide important references for long-term forecasts of winter energy demand and the construction of climate change response infrastructure to prevent climate disasters such as the 2021 Texas power outage." [Fig 1] Winter temperature trend - Observed temperature trends during the winters (Dec-Feb) of 1995/96-2021/22. [Fig 2] Atlantic & Pacific ocean fronts - Ocean fronts near the Gulf Stream and Kuroshio Currents that represent narrow regions where sea surface temperature sharply decreases northward. [Fig 3(Attachment notes)] Gulf stream & East Asia covariability - Decadal cooling in East Asia accompanied by Gulf Stream warming (climate model simulation) ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/ The research, which was funded by the Ministry of Science and ICT (Minister Jong-ho Lee) through the Mid-Career Researcher Support Project (2021R1A2C1003934), the Leading Research Center Support Project (2018R1A5A1024958), and the Ultra-High Performance Computing Utilization Advancement Project (2022M3K3A1094114), was published on November 27 in the international journal Nature Communications Journal : Nature Communications Title : Ocean fronts as decadal thermostats modulating continental warming hiatus Publication Date : 2023.11.27. DOI : https://doi.org/10.1038/s41467-023-43686-1
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- WriterDr. Sung, Mi-Kyung
- 작성일2024.02.05
- Views162
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Quickly and easily predict emerging contaminant concentrations in wastewater with artificial intelligence
The global consumption of pharmaceuticals is growing rapidly every year, reaching 4 billion doses in 2020. As more and more pharmaceuticals are metabolized by the human body and enter sewage and wastewater treatment plants, the amount and types of trace substances found in them are also increasing. When these trace substances enter rivers and oceans and are used as water sources, they can have harmful effects on the environment and human health, including carcinogenesis and endocrine disruption. Therefore, technologies are needed to quickly and accurately predict the properties and behavior of these trace substances, but analyzing unknown trace substances requires expensive equipment, skilled experts, and a long time. The Korea Institute of Science and Technology (KIST) announced that a team led by Hong Seok-won, head of the Water Resources and Cycle Research Center, and Son Moon, a senior researcher, has developed a technology to classify emerging trace substances according to their physicochemical properties and predict their concentrations using clustering and prediction-based artificial intelligence technology. The researchers used self-organizing maps, an AI technique that clusters data into maps based on their similarities, to classify 29 known trace substances, including medicinal compounds and caffeine, based on information such as physicochemical properties, functional groups, and biological reaction mechanisms. Random forests, a machine learning technique that classifies data into subsets, were then further built to predict the properties and concentration changes of new trace substances. If a new trace substance belongs to a cluster in the self-organizing map, the properties of other substances in that cluster can be used to predict how the properties and concentration of the new trace substance will change. As a result of applying this clustering and prediction AI model (self-organizing map and random forest) to 13 new trace substances, the prediction accuracy of about 0.75 was excellent, far exceeding the prediction accuracy of 0.40 of existing AI techniques using biological information. Compared to traditional prediction methods based on formulas, the KIST research team's data-driven analysis model has the advantage of only inputting the physicochemical properties of trace substances and efficiently identifying how the concentration of new trace substances will change in the sewage treatment process through clustering with substances with similar data. In addition, the data-driven AI model can be used in the future to predict the concentration of new substances such as drugs that are of social concern. "It can be applied not only to actual wastewater treatment plants, but also to most water treatment-related facilities where new trace substances exist, and can provide quick and accurate data in the policy-making process for related regulations," said Dr. Seokwon Hong and Dr. Moon Son (co-corresponding authors) of KIST. “Since it utilizes machine learning technology, the accuracy of the prediction will improve as relevant data is accumulated.” [Fig 1] Machine learning approaches for predicting the behavior of new trace substances ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/ This study was supported by the Korea Environment Industry & Technology Institute through the "Project for developing innovative drinking water and wastewater technologies," funded by the Korea Ministry of Environment [Grant No. 2019002710010], and the National Research Foundation of Korea (NRF) grant, funded by the Korean government (MSIT) [No. 2021R1C1C2005643]. The results were published in the October issue of the npj Clean Water (IF: 11.4, top 1.5% in JCR Water Resources). Journal : npj Clean water Title : Clustering micropollutants and estimating rate constants of sorption and biodegradation using machine learning approaches Publication Date : 2023.10.28. DOI : https://doi.org/10.1038/s41545-023-00282-6
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- WriterDr. Hong, Seok-won, Dr. Son, Moon
- 작성일2024.02.05
- Views88
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Hybrid energy harvesters that harness heat and vibration simultaneously
- Developing a hybrid energy harvester that goes beyond simple coupling of thermoelectric and piezoelectric devices to generate higher power - Commercial GPS positioning sensor runs successfully, showing promise for real-world applications Harvesting energy sources such as heat, vibration, light, and electromagnetic waves from everyday environments such as industrial sites and automobiles and converting them into electrical energy is known as energy harvesting. Energy harvesting makes it easier to power today's popular IoT sensors and wireless devices that are located in environments where battery replacement is difficult. Dr. Hyun-Cheol Song and Dr. Sunghoon Hur of Electronic Materials Research Center at the Korea Institute of Science and Technology (KIST) have developed a hybrid energy harvesting system that increases power production by more than 50% by combining thermoelectric and piezoelectric effects. The thermoelectric effect, which converts thermal energy from both ends of the device into electrical energy, has a low energy conversion efficiency, and the piezoelectric effect, which converts mechanical vibration into electrical energy, has a high impedance, so energy cannot be reliably harvested. To overcome the limitations of single-mode energy harvesters, hybrid energy harvesters have been proposed in the past, but they are mainly based on simply combining the energy generated by each mechanism. In response, the KIST research team developed a thermoelectric-piezoelectric hybrid energy harvester that complements the shortcomings of thermoelectric and piezoelectric devices to create a synergistic effect in environments with heat sources and vibrations. First, instead of a heat sink, which is a static shape with a large cross-sectional area that is bulky and in contact with air, a cantilever was fabricated to improve the heat dissipation effect in a vibration environment, resulting in a thermoelectric device output that was improved by more than 25%. The researchers also proposed a hybrid energy harvesting structure in which a polymer-type piezoelectric device (MFC) was attached to the cantilever to generate additional power by generating tensile and compressive deformation of the piezoelectric device as the cantilever shakes. The research team successfully applied this hybrid energy harvester to stably drive a commercial IoT sensor (GPS positioning sensor, 3 V, 20 mW), demonstrating the potential for future IoT sensors to run continuously without battery power supply. "This study confirms that the hybrid energy harvesting system can be reliably applied to our real life," said Dr. Sunghoon Hur of KIST, who led the research. "We have confirmed its effectiveness in places where heat and vibration exist together, such as automobile engines, and are currently planning to build a system that can be applied to factory facilities or construction machinery engines that are difficult to supply power and diagnose their condition wirelessly." [Fig 1] Thermoelectric-voltaic hybrid harvester utilizing a cantilevered dynamic heat sink developed by KIST researchers [Fig 2] Graph showing the characteristics of a thermoelectric-voltaic hybrid harvester utilizing a cantilevered dynamic heat sink. [Fig 3] Illustration and graph showing that the output of a thermoelectric-piezoelectric hybrid harvester can be used to reduce IoT sensor drive time, increasing hybrid power due to the synergy of the thermoelectric-piezoelectric mechanism. ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/ The research was supported by the Ministry of Science and ICT (Minister Jong-ho Lee) as Institutional Program of KIST and was published in the latest issue of Energy Conversion and Management (IF: 10.4, top 1.8% in JCR), an international journal in the energy field. Journal : Energy Conversion and Management Title : A synergetic effect of piezoelectric energy harvester to enhance thermoelectric Power: An effective hybrid energy harvesting method Publication Date : 2023.10.30. DOI : https://doi.org/10.1016/j.enconman.2023.117774
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- WriterDr. Hur, Sunghoon
- 작성일2024.02.05
- Views93
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Quantum material-based spintronic devices operate at ultra-low power
- First development of spintronic device consisting of two-dimensional ferromagnetic-ferroelectric material heterostructure, observation of low-power voltage-driven device operation - Developed next-generation spin memory technology to secure technological advantage in the domestic semiconductor industry As artificial intelligence technologies such as Chat-GPT are utilized in various industries, the role of high-performance semiconductor devices for processing large amounts of information is becoming increasingly important. Among them, spin memory is attracting attention as a next-generation electronics technology because it is suitable for processing large amounts of information with lower power than silicon semiconductors that are currently mass-produced. Utilizing recently discovered quantum materials in spin memory is expected to dramatically improve performance by improving signal ratio and reducing power, but to achieve this, it is necessary to develop technologies to control the properties of quantum materials through electrical methods such as current and voltage. Dr. Jun Woo Choi of the Center for Spintroncs Research at the Korea Institute of Science and Technology (KIST) and Professor Se-Young Park of the Department of Physics at Soongsil University (President Beom-Sik Jang) have announced the results of a collaborative study showing that ultra-low-power memory can be fabricated from quantum materials. By applying a voltage to a quantum material spintronic device consisting of two-dimensional material heterostructure, it is possible to read and write information at ultra-low power by effectively controlling the spin information of electrons. Two-dimensional materials, which are representative quantum materials, can be easily separated into planar layers of single atoms, unlike ordinary materials that have a three-dimensional structure, and thus exhibit special quantum mechanical properties. In this study, we developed a two-dimensional heterostructure device that combines quantum materials with two different properties for the first time. By applying voltage as low as 5 V to a device consisting of a two-dimensional ferromagnetic material (Fe3-xGeTe2) and a two-dimensional ferroelectric material (In2Se3) stacked on top of each other, the magnetic field required to change the spin direction of the ferromagnet, i.e., the coercivity, can be reduced by more than 70%. The researchers also found that the structural changes in the two-dimensional ferroelectric that occur when a voltage is applied lead to changes in the spin properties of neighboring two-dimensional ferromagnets. The lattice of the two-dimensional ferroelectric expands with voltage, changing the magnetic anisotropy of the adjacent ferromagnet and greatly reducing the coercivity required to reorient the spin. This means that by applying a very small voltage to a quantum material heterostructure device, it is possible to control the spin information of electrons even with an approximately 70% reduced magnetic field, which is a key technology for the development of ultra-low-power spin memory based on quantum materials. "By securing ultra-low-power next-generation memory core element technology using quantum materials, we will be able to maintain our technological edge and competitiveness in the recently faltering semiconductor industry," said Dr. Jun Woo Choi of KIST. [Fig 1] Schematics and optical image of the two-dimensional(2D) material heterostructure device (a) Device schematics of two-dimensional(2D) ferromagnet-ferroelectric heterostructure device. (b) Optical image of the fabricated device. [Fig 2] Operation of the two-dimensional(2D) ferromagnet-ferroelectric heterostructure device (a) Operation scheme of the heterostructure device. Voltage-induced lattice expansion modulates the magnetic properties of the ferromagnet. (b) Voltage-dependent measurement of the magnetic properties. (c) The coercivity as a function of applied voltage. ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/ KIST Institutional Program (2E32251, 2E32252), Mid-Career Research Support Project (NRF-2021R1A2C2011007), Leading Research Center Support Project (NRF- 2020R1A5A1016518), and Nanomaterial Technology Development Project (NRF-2021M3H4A1A03054856) from the Ministry of Science and ICT (Minister Lee Jong-ho), (NRF-2021R1C1C1009494), and the National Research Foundation for Young Researchers (NRF-2021R1A6A1A03043957), this research was published in the international journal 「Nature Communications」. Journal : Nature Communications Title : Voltage control of magnetism in Fe3-xGeTe2/In2Se3 van der Waals ferromagnetic/ferroelectric heterostructures Publication Date : 2023.09.12. DOI : https://doi.org/10.1038/s41467-023-41382-8
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- WriterDr. Choi, Jun Woo
- 작성일2024.02.05
- Views116
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KIST's 'Moonwalk', a robot that makes climbing Bukhansan Mountain easier
- Elderly man wears robot to climb Bukhansan Mountain in wearable robotics challenge - Wearable robots are leaving the hospital and entering our lives. As people age, they gradually lose muscle strength in their arms and legs, making it difficult for them to participate in leisure activities such as hiking and traveling, and they often need to rely on assistive devices such as canes and wheelchairs for mobility. However, these assistive devices do not improve muscle strength, so wearable robots that can compensate for the lack of muscle strength with the help of robots are attracting attention as an innovative technology to improve the health and quality of life of the elderly. Dr. Lee Jongwon of the Intelligent Robotics Research Center at the Korea Institute of Science and Technology(KIST) has developed a wearable robot, MOONWALK-Omni, which means 'to actively support leg strength in any direction(omnidirection) to help walk like walking on the moon', has announced that a senior citizen wearing it successfully completed a wearable robot challenge to climb to the top of Mount Yeongbong (604 meters above sea level) in Korea. The challenge raised the possibility of commercializing wearable robots in outdoor complex environments by successfully climbing with the help of the robot's muscle strength without changing batteries or intervention from developers. Various types of wearable robots have been developed in the past, but due to their heavy weight and large volume, they have been limited to the rehabilitation process of patients in hospitals with simple indoor environments. However, MOONWALK-Omni is an ultra-lightweight wearable strength-assistance robot that predicts the user's movements and supports insufficient leg strength to help the elderly rehabilitate and assist with daily activities. The 2-kilogram device can be easily donned by an older adult in less than 10 seconds without assistance, and its four ultra-lightweight, high-powered actuators on either side of the pelvis help balance the user while walking and boost the wearer's leg strength by up to 30 percent to increase propulsion. The robot's artificial intelligence (AI) analyzes the wearer's gait in real time and provides safe and effective muscle support in a variety of walking environments, including gentle slopes, rough rocky paths, steep wooden stairs, and uneven stone steps. Through the Bukhansan Mountain Wearable Robot Challenge, the research team succeeded in verifying the performance and reliability of muscle support using wearable robots in everyday environments that are more complex than hospitals. An elderly participant in the challenge said, "I thought I would have to give up mountain climbing, which I have enjoyed since I was young, but I feel 10 to 20 years younger after climbing the mountain comfortably with the wearable robot," and shared his impressions of climbing the mountain with the wearable robot. Dr. Lee Jong-won of KIST said, "Through this challenge, we have obtained experimental data that shows that safe and effective strength support is possible in a variety of walking environments." "Through the convergence of ultra-lightweight, high-power wearable robot drive technology and personalized artificial intelligence strength support technology, it is expected to be widely used in the fields of daily assistance, rehabilitation, and exercise for the elderly who lack muscle strength due to aging." As a follow-up to MOONWALK-Omni, the research team is developing MOONWALK-Support, which not only strengthens leg muscles but also supports the complex joints of the lower extremities such as hip and knee. In addition, the team has achieved achievements in various fields by transferring core technologies and components such as motors, reducers, and computing circuits for wearable robots to company in Korea. [Figure 1] (Bukhansan Challenge)An elderly man walks up a complex stone staircase environment while wearing a robot during a wearable challenge in Korea. [Figure 2] (Bukhansan Challenge)A 65-year-old man successfully climbs to the top of Mount Yongbong in Bukhansan Mountain using a wearable robot and muscle support. [Figure 3] Image of the wearable robot MOONWALK-Omni ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://kist.re.kr/eng
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- WriterDr. Lee Jongwon
- 작성일2024.01.30
- Views289
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Developing nanocatalysts to overcome limitations of water electrolysis technology
- Developing nanocatalysts that do not degrade at high temperatures above 600 degrees Celsius - More than doubling green hydrogen production with high-temperature water electrolysis cells Green hydrogen can be produced through water electrolysis technology, which uses renewable energy to split water into hydrogen and oxygen without emitting carbon dioxide. However, the production cost of green hydrogen is currently around $5 per kilogram, which is two to three times higher than gray hydrogen obtained from natural gas. For the practical use of green hydroten, the innovation in water electrolysis technology is required for the realization of hydrogen economy, especially for Korea where the utilization of renewable energy is limited owing to geographical reasons. Dr. Kyung Joong Yoon’s research team at the Energy Materials Research Center of the Korea Institute of Science and Technology (KIST) has developed a nanocatalyst for high-temperature water electrolysis that can retain a high current density of more than 1A/cm2 for a long time at temperatures above 600 degrees. While the degradation mechanisms of nanomaterials at high temperatures have been elusive thus far, the team identified the fundamental reasons of abnormal behavior of nanomateirals and successfully resolved issues, eventually improving performance and stability in realistic water electrolysis cells. The electrolysis technology can be classified into low- and high-temperature electrolysis. While low-temperature electrolysis operating at temperatures below 100 degrees Celsius has long been developed and is technologically more mature, high-temperature electrolysis operating above 600 degrees Celsius offers higher efficiency and is considered as a next-generation technology with a strong potential for further cost-down. However, its commercialization has been hindered by the lack of thermal stability and insufficient lifetime owing to high-temperature degradation, such as corrosion and structural deformation. In particular, nanocatalysts, which are widely used to improve the performance of low-temperature water electrolyzers, quickly deteriorate at high operating temperatures, making it difficult to effectively use them for high-temperature water electrolysis. To overcome this limitation, the team developed a new nanocatalyst synthetic techniques that suppresses the formation of harmful compounds causing high temperature degradation. By systematically analyzing the nanoscale phenomena using transmission electron microscopy, the researchers identified specific substances causing severe structural alterations, such as strontium carbonate and cobalt oxide and successfully removed them to achieve highly stable nanocatalysts in terms of chemical and physical properties. When the team applied the nanocatalyst to a high-temperature water electrolysis cell, it more than doubled hydrogen production rate and operated for more than 400 hours at 650 degrees without degradation. This technique was also sucessfully applied to a practical large-area water electrolysis cell, confirming its strong potential for scale-up and commercial use. "Our newly developed nanomaterials achieved both high performance ans stability for high-temperature water electrolysis technology, and it can contribute to lower the production cost of green hydrogen, making it economically competitive with gray hydrogen in the future," said Dr. Kyungjoong Yoon of KIST. "For commercialization, we plan to develop automated processing techniques for mass production in cooperation with industry cell manufacturers." [Figure 1] Manufacturing process and evaluation results of high temperature water electrolysis cell with nanomaterials ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/ This research was supported by the Ministry of Science and ICT (Minister Lee Jong-ho) through the KIST Major Project and Climate Change Response Technology Development Project (2020M1A2A2080862), and the results were published in the latest issue of the Chemical Engineering Journal (IF 15.1, top 3.2% in JCR), an international journal in the field of chemical engineering. Journal : Chemical Engineering Journal Title : In situ synthesis of extremely small, thermally stable perovskite nanocatalysts for high-temperature electrochemical energy devices Publication Date : 2023.10.24. DOI : https://doi.org/10.1016/j.cej.2023.146924
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- WriterDr.Yoon, Kyung Joong
- 작성일2024.01.09
- Views282
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Artificial intelligence lowers the barrier to ultrasound brain disease treatment
- Developing real-time focused ultrasound simulation technology using generative AI models - Expected to improve the accuracy and safety of brain disease treatment with focused ultrasound Focused ultrasound technology is a non-invasive treatment method that focuses ultrasound energy on a few millimeters of the brain, including deep regions, to treat neurological disorders without opening the skull. It has been applied to the treatment of various intractable brain diseases such as depression and Alzheimer's disease because it minimizes the impact on the surrounding healthy tissue and reduces side effects such as complications and infections. However, its use has been limited so far because it is difficult to reflect the distortion of ultrasound waves caused by the different shapes of the skulls of different patients in real-time. A research team led by Dr. Kim, Hyungmin of the Bionics Research Center at the Korea Institute of Science and Technology (KIST) has developed a real-time acoustic simulation technology based on generative AI to predict and correct the distortion of the ultrasound focus position caused by the skull in real-time during focused ultrasound therapy. Until now, the clinical applicability of AI simulation models in the field of non-invasive focused ultrasound therapy technology has not been validated. To predict the location of the invisible acoustic focus, navigation systems based on medical images taken before treatment are currently utilized, which provide information about the relative position of the patient and the ultrasound transducer. However, they are limited by their inability to account for the distortion of ultrasound waves caused by the skull, and while various simulation techniques have been used to compensate for this, they still require significant computational time, making them difficult to apply in actual clinical practice. The research team developed a real-time focused ultrasound simulation technology through an artificial intelligence model based on a generative adversarial neural network (GAN), a deep learning model widely used for image generation in the medical field. The technology reduces the update time of three-dimensional simulation information reflecting changes in ultrasound acoustic waves from 14 s to 0.1 s, while showing an average maximum acoustic pressure error of less than 7% and a focal position error of less than 6mm, both of which are within the error range of existing simulation technologies, increasing the possibility of clinical application. The research team also developed a medical image-based navigation system to verify the performance of the developed technology in order to rapidly deploy it to real-world clinical practice. The system can provide real-time acoustic simulations at the rate of 5 Hz depending on the position of the ultrasound transducer, and succeeded in predicting the position of the ultrasound energy and focus within the skull in real-time during focused ultrasound therapy. Previously, due to the long calculation time, the ultrasound transducer had to be precisely positioned in a pre-planned location to utilize the simulation results. However, with the newly developed simulation-guided navigation system, it is now possible to adjust the ultrasound focus based on the acoustic simulation results obtained in real-time. In the future, it is expected to improve the accuracy of focused ultrasound and provide safe treatment for patients by being able to quickly respond to unexpected situations that may occur during the treatment process. "As the accuracy and safety of focused ultrasound brain disease treatment has been improved through this research, more clinical applications will emerge," said Dr. Kim, Hyungmin of KIST. "For practical use, we plan to verify the system by diversifying the ultrasound sonication environment, such as multi-array ultrasound transducers." [Figure 1] Simulation-Guided Navigation Systems [Figure 2] Clinical Application Examples for Simulation-Guided Navigation ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/ This research was supported by the Ministry of Science and ICT (Minister Lee Jong-ho) under the Creative Convergence Research Project (CAP-18014-000) of the National Research Council of Korea. The research results were published on October 14 in the top international journal NeuroImage (top 3.6% in JCR). Journal : NeuroImage Title : Real-Time Acoustic Simulation Framework for tFUS: A Feasibility Study Using Navigation System Publication Date : 2023.10.14. DOI : https://doi.org/10.1016/j.neuroimage.2023.120411
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- WriterDr. Kim, Hyungmin
- 작성일2024.01.09
- Views220
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Investigation of degradation mechanism for all-solid-state batteries takes another step toward commercialization
- New findings reveal how degradation of all-solid-state batteries occurs at the cathode under low-pressure operation - Clues to accelerate commercialization of all-solid-state batteries Often referred to as the ‘dream batteries’, all-solid-state batteries are the next generation of batteries that many battery manufacturers are competing to bring to market. Unlike lithium-ion batteries, which use a liquid electrolyte, all components, including the electrolyte, anode, and cathode, are solid, reducing the risk of explosion, and are in high demand in markets ranging from automobiles to energy storage systems (ESS). However, devices that maintain the high pressure (tens of MPa) required for stable operation of all-solid-state batteries have problems that reduce the battery performance, such as energy density and capacity, and must be solved for commercialization. Dr. Hun-Gi Jung and his team at the Energy Storage Research Center at the Korea Institute of Science and Technology (KIST) have newly identified degradation factors that cause rapid capacity degradation and shortened lifespan when operating all-solid-state batteries at pressures similar to those of lithium-ion batteries. Unlike previous studies, the researchers confirmed for the first time that degradation can occur inside the cathode as well as outside, showing that all-solid-state batteries can be operated reliably even in low-pressure environments in the future. [Figure 1] Comparison of cathode volume changes in all-solid-state cells under low-pressure operated In all-solid-state batteries, the cathode and anode have a volume change during repeated charging and discharging, resulting in interfacial degradation such as side reaction and contact loss between active materials and solid electrolytes, which increase the interfacial resistance and worsen cell performance. To solve this problem, external devices are used to maintain high pressure, but this has the disadvantage of reducing energy density as the weight and volume of the battery increase. Recently, research is being conducted on the inside of the all-solid-state cell to maintain the performance of the cell even in low-pressure environments. [Figure 2] Schematic image of cathode degradation in all-solid-state battery under low-pressure operation The research team analyzed the cause of performance degradation by repeatedly operating a coin-type all-solid-state battery with a sulfide-based solid electrolyte in a low-pressure environment of 0.3 MPa, similar to that of a coin-type Li-ion battery. After 50 charge-discharge cycles, the NCM cathode layer had expanded in volume by about two times, and cross-sectional image analysis confirmed that severe cracks had developed between the cathode active material and the solid electrolyte. This newly revealed that in addition to the interfacial contact loss, cracking of the cathode material and irreversible cathode phase transformation are the causes of degradation in low-pressure operation. Furthermore, after replacing the lithium in the cathode with an isotope (6Li) to distinguish it from the lithium present in the solid electrolyte, the team used time-of-flight secondary ion mass spectrometry (TOF-SIMS) to identify for the first time the mechanism by which lithium consumption in the cathode contributes to the overall cell capacity reduction. During repeated charge-discharge cycles, sulfur, a decomposed product of the solid electrolyte, infused the cracks in the cathode material to form lithium sulfide, a byproduct that is non-conductive. This depleted the active lithium ions and promoted cathode phase transformation, reducing the capacity of the all-solid-state batteries. [Figure 3] The front cover image By clearly identifying the cause of the degradation of all-solid-state batteries in low-pressure operating environments, these analytical methods provide a clue to solving the problem of poor cycling characteristics compared to conventional lithium-ion batteries. If this problem is solved, it is expected that the economics of all-solid-state batteries can be secured by eliminating external auxiliary devices, which have been a major cause of rising production costs. "For the commercialization of all-solid-state batteries, it is essential to develop new cathode and anode materials that can be operated in a pressure-free or low-pressure environment rather than the current pressurized environment," said Dr. Hun-Gi Jung of KIST. "When applying low-pressure-working all-solid-state batteries to medium and large-scale applications such as electric vehicles, it will be expected to make full use of established lithium-ion battery manufacturing facilities." ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/ This research was supported by the Korea Institute of Science and Technology institutional program funded by the Ministry of Science and ICT of Korea (Minister Lee Jong-ho), by the Development Program of Core Industrial Technology funded by the Ministry of Trade, Industry and Energy (Minister Bang, Moon Kyu), and by the Technology Development Program to Solve Climate Changes funded by the National Research Foundation (President Lee, Kwang-bok). The research results were published as a front cover article in the latest issue of Advanced Energy Materials (IF 27.8, top 2.5% in JCR), an international journal in the field of energy materials. Journal : Advanced Energy Materials Title : New Consideration of Degradation Accelerating of All-Solid-State Batteries under a Low-Pressure Condition Publication Date : 27-Oct-2023 DOI : https://doi.org/10.1002/aenm.202301220
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- WriterDr. Jung, Hun-Gi
- 작성일2023.12.04
- Views446
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Safely removing nanoplastics from water using 'Prussian blue', a pigment used to dye jeans
- Microplastics can be removed by 99% with flocculants alone, without any additional equipment, by irradiating them with sunlight. Plastic waste breaks down over time into microplastics (<0.1 μm). Microplastics smaller than 20 μm cannot be removed in currently operating water treatment plants and must be agglomerated to a larger size and then removed. Iron (Fe) or aluminum (Al) based flocculants are used for this purpose, but they are not the ultimate solution as they remain in the water and cause severe toxicity to humans, requiring a separate treatment process. Dr. Jae-Woo Choi of the Center for Water Cycle Research at the Korea Institute of Science and Technology (KIST) has developed an eco-friendly metal-organic skeleton-based solid flocculant that can effectively aggregate nanoplastics under visible light irradiation. Prussian blue, a metal-organic frameworks-based substance made by adding iron (III) chloride to a potassium ferrocyanide solution, is the first synthetic pigment used to dye jeans a deep blue color and has recently been used to adsorb cesium, a radioactive element, from Japanese nuclear plant wastewater. While conducting experiments on the removal of radioactive materials from water using Prussian blue, the KIST research team discovered that Prussian blue effectively aggregates microplastics under visible light irradiation. [Figure 1] NANOPLASTIC TREATMENT USING FEHCF NANOBOTS UNDER VISIBLE-LIGHT IRRADIATION The research team developed a material that can effectively remove microplastics by adjusting the crystal structure to maximize the aggregation efficiency of Prussian blue. When the developed material is irradiated with visible light, microplastics with a diameter of about 0.15 μm (150 nm), which are difficult to remove using conventional filtration technology, can be agglomerated to a size about 4,100 times larger, making them easier to remove. In experiments, the researchers found that they were able to remove up to 99% of microplastics from water. The developed material is also capable of flocculating microplastics more than three times its own weight, outperforming the flocculation efficiency of conventional flocculants using iron or aluminum by about 250 times. [Figure 2] Schematics of the preparation of the FeHCH nanobots and process for NP removal The material not only uses Prussian blue, which is harmless to the human body, but is also a solid flocculant, making it easy to recover residues in water. It also uses natural light as an energy source, enabling a low-energy process. "This technology has a high potential for commercialization as a candidate material that can be applied to general rivers, wastewater treatment facilities, and water purification plants," said Dr. Choi of KIST. "The developed material can be utilized not only for nanoplastics in water, but also to clean up radioactive cesium, thus providing safe water." Meanwhile, Dr. Youngkyun Jung, the first author of the paper, said, "The principle of this material can be utilized to remove not only microplastics, but also a variety of contaminants in water systems." ### KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://eng.kist.re.kr/ The research, which was supported by the Ministry of Science and ICT (Minister Lee Jong-ho) through the Material Innovation Leading Project (2020M3H4A3106366) and the KIST Institutional Project (2E32442), was published on October 1 in the international journal Water Research*. Journal : Water Research Title : Visible-light-induced Self-propelled Nanobots Against Nanoplastics Publication Date : 1-October-2023 DOI :https://doi.org/10.1016/j.watres.2023.120543
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- WriterDr. Choi, Jae Woo
- 작성일2023.10.20
- Views1505