Latest Research News
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Developing a stem cell therapy to prevent amputations from critical limb ischemia
Critical limb ischemia is a condition in which the main blood vessels supplying blood to the legs are blocked, causing blood flow to gradually decrease as atherosclerosis progresses in the peripheral arteries. It is a severe form of peripheral artery disease that causes progressive closure of arteries in the lower extremity, leading to the necrosis of the leg tissue and eventual amputation. Current treatments include angioplasty procedures such as stent implantation and anti-thrombotic drugs, but there is a risk of blood vessel damage and recurrence of blood clots, which is why there is a strong interest in developing a treatment using stem cells. A research team led by Dr. Sangheon Kim of the Center for Biomaterials Research at the Korea Institute of Science and Technology (KIST) announced that they have developed a three-dimensional stem cell therapy to treat critical limb ischemia through a self-assembling platform technology using a new material microgel. By using collagen microgels, a new biocompatible material, the researchers were able to easily transplant stem cells into the body and increase cell survival rate compared to 3D stem cell therapies made of cells alone. Stem cell therapies have high tissue regeneration capabilities, but when stem cells are transplanted alone, hypoxia at the site of injury, immune responses, and other factors can reduce cell viability and prevent the desired therapeutic effect. Therefore, it is necessary to develop a material that delivers stem cells using biodegradable polymers or components of extracellular matrix as a support to increase cell viability. The team processed collagen hydrogels to micro-scale to create porous, three-dimensional scaffolds that are easy to inject in the body and have a uniform cell distribution. Collagen, a component of the extracellular matrix, has excellent biocompatibility and cellular activity, which can induce cell self-assembly by promoting interactions between the microgel particles and collagen receptors on stem cells. In addition, the spacing between microgel particles increased the porosity of the three-dimensional constructs, improving delivery efficiency and cell survival. The microgel-cell constructs developed by the researchers expressed more pro-angiogenic factors and exhibited higher angiogenic potential than cell-only constructs. When microgel-cell constructs were injected into the muscle tissue of mice with critical limb ischemia, blood perfusion rate increased by about 40% and limb salvage ratio increased by 60% compared to the cell-only constructs, confirming their effectiveness in increasing blood flow and preventing necrosis in the ischemic limb. The new stem cell therapy is expected to provide a new alternative for patients with critical limb ischemia who have limited treatment options other than amputation due to its excellent angiogenic effect. Furthermore, since angiogenesis is an essential component of various tissue regeneration processes, it can be extended to other diseases with similar mechanisms to peripheral arterial disease. "The collagen microgel developed in this study is a new biomaterial with excellent biocompatibility and high potential for clinical applications," said Dr. Sangheon Kim of KIST. "We plan to develop technologies for administration methods required in the medical field, as well as conduct follow-up research to clarify the clear mechanism of action of the treatment and discover target factors." [Figure1] Collagen Microgels - The Concept of Self-Assembling Stem Cell Therapy [Figure2] Enhanced cell viability of microgel-assembled stem cell therapeutics [Figure3] Efficacy validation of microgel-cell constructs ### 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 Korean Fund for Regenerative Medicine (22C0620L1). The findings were published in the latest issue of the international journal Bioactive Materials (IF 18.9, JCR top 1.1%). Journal : Bioactive Materials Title : A micro-fragmented collagen gel as a cell-assembling platform for critical limb ischemia repair Publication Date : 2023.12.16. DOI : https://doi.org/10.1016/j.bioactmat.2023.12.008
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- WriterDr. Sangheon Kim
- 작성일2024.03.13
- Views214
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New treatment developed to dramatically slow down the progression of blindness-causing retinal diseases:
- Interactive release of anti-inflammatory drugs depending on the level of retinal degeneration. - A customized treatment approach is expected to be developed to reduce patients’ inconvenience of having multiple shots. The Korea Institute of Science and Technology (KIST) announced that Dr. Maesoon Im of the Brain Science Institute, together with Prof. Seung Ja Oh of Kyung Hee University and Prof. Kangwon Lee of Seoul National University, successfully incorporated anti-inflammatory drugs into a hydrogel to suppress inflammation in the retina and effectively deliver the drugs to the inflamed area. Age-related macular degeneration and retinitis pigmentosa are incurable eye diseases that cause blindness due to the gradual damage of photoreceptor cells, which convert light into biological signals in the retina, the light-sensitive tissue at the back of the eye. Age-related macular degeneration is a condition that damages the macula, the central part of the retina, and is the number one cause of blindness in people over the age of 65. Retinitis pigmentosa, on the other hand, is a genetic disorder that causes gradual death in the photoreceptor cells in the retina and affects about 1 in 4,000 people worldwide, initially causing night blindness but eventually leading to vision loss. Currently, there is no effective cure for either disease, and one of the treatments is to inject anti-inflammatory drugs into the eye to slow down the degree of retinal damage. However, these injections only work for as long as the drug remains in the eye, requiring patients to visit a clinic for intraocular injections every four to 12 weeks, depending on how long the effect of the drug lasts. For the first time, the team utilized a substance that inhibits the inflammatory factor EZH2, which contributes to retinal degeneration, along with an anti-inflammatory agent. When mice with retinal degeneration were injected with the anti-inflammatory drug, the progression of retinal degeneration slowed down. The researchers have successfully developed a hydrogel that slowly degrades upon encountering the enzyme cathepsin, which is typically overexpressed in inflammatory environments, to deliver anti-inflammatory drugs. When the team's drug-loaded inflammation-responsive hydrogel was injected into the eyes of mice suffering from retinal degeneration, inflammatory factors in the retina were reduced to approximately 6.1%. The team also found that the protective effect on photoreceptor cells, which are known to be destroyed by retinal degeneration, was about four times higher than in the control group, effectively delaying vision loss. Notably, the hyaluronic acid-based hydrogel, which has similar mechanical and optical properties to the vitreous humor of the eye, allows for different rates of hydrogel degradation in each patient, minimizing the need for repeated injections. This newly developed technology is expected to reduce the economic burden and the risk of accidents during outpatient visits for patients with difficulty in mobility due to visual impairment. Additionally, for patients in the early stages of symptoms, reducing the frequency of hospital visits can alleviate inconvenience in daily life. "For future commercialization, we plan to digitize the amount of drug and hydrogel used, as well as the treatment period, according to the progression of the disease. We also intend to assess the long-term stability of the drug delivery system," said Dr. Maesoon Im of KIST. "In addition to the retinal degenerative diseases, we will investigate inflammation levels in other retinal diseases to see if our inflammation-responsive drug delivery system would work on those conditions," said Prof. Seung Ja Oh of Kyung Hee University. [Figure 1] Schematic illustration of syringe-injectable inflammation-responsive hydrogel for suppression of inflammatory microglia for preventing photoreceptor death in retinitis pigmentosa. [Figure 2] The effectiveness of the developed inflammation-responsive drug was verified. ### 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 Young and Mid-Career Researchers, the Excellent Young Researcher Support Project, the Brain Function Identification and Regulation Technology Development Project, and the Public Benefit Medical Technology Research Project of the Ministry of Health and Welfare (Minister Cho Kyu-hong). The research were published in the latest issue of the international journal 'npj Regenerative Medicine' (IF 7.2, top 19.3% in JCR). Journal : npj Regenerative Medicine Title : Effective Protection of Photoreceptors Using an Inflammation-Responsive Hydrogel to Attenuate Outer Retinal Degeneration Publication Date : 2023.12.14. DOI : https://doi.org/10.1038/s41536-023-00342-y
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- WriterDr. Im Maesoon
- 작성일2024.02.14
- Views333
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KIST-LLNL raises expectations for commercialization of high-energy-density all-solid-state batteries
- Computational science-based high-voltage stable solid electrolyte material design principles suggested - Anticipating commercialization of next-generation lithium all-solid-state batteries with high energy density and no fire risk Researchers are actively working on non-flammable solid electrolytes as a safer alternative to liquid electrolytes commonly found in lithium-ion batteries, which are vulnerable to fires and explosions. While sulfide-based solid electrolytes exhibit excellent ionic conductivity, their chemical instability with high-voltage cathode materials necessary for high-energy-density batteries has impeded their commercial viability. Consequently, there has been a growing interest in chloride-based solid electrolytes, which are stability in high-voltage conditions due to their strong bonding properties. The Korea Institute of Science and Technology (KIST; President: Dr. Seok-Jin Yoon) announced that a KIST-LLNL joint research team led by Dr. Seungho Yu of the Energy Storage Research Center, Dr. Sang Soo Han of the Computational Science Research Center, and Dr. Brandon Wood of Lawrence Livermore National Laboratory (LLNL) has developed a fluorine substituted high-voltage stable chloride-based solid-state electrolyte through computational science. LLNL is a leading national laboratory under the U.S. National Nuclear Security Administration, renown for its excellent supercomputing facilities. Since 2019, KIST and LLNL have been conducting collaborative research in the field of secondary batteries. To improve the high-voltage stability of chloride-based solid electrolyte (Li3MCl6), the research team proposed the optimal composition and design principle of chloride-based solid electrolyte (Li3MCl5F) substituted with fluorine(F), which has strong chemical bonding ability. For the proposed strategy to improve the high-voltage stability of chloride-based solid electrolytes by KIST, LLNL contributed by utilizing their cutting-edge supercomputing resources for calculations and subsequent experimental validations were conducted at KIST. The collaborative research team adopted a cost-effective and time-saving strategy, wherein computational science guides the initial material design, followed by rigorous laboratory validation. The chloride-based solid electrolyte synthesized based on the design principle proposed by the research team was applied to an all-solid-state battery to evaluate its electrochemical stability under high-voltage conditions. Impressively, it showed high-voltage stability exceeding 4 V, comparable to that of commercial lithium-ion batteries with liquid electrolytes. Accordingly, fluorine(F)-substituted chloride-based solid electrolytes are expected to replace sulfide-based solid electrolytes that are unstable at high voltages, accelerating the commercialization of all-solid-state batteries. The Korea-U.S. Joint Research Team will conduct follow-up research on the synthesis process of the material, alongside the optimization of electrode and cell manufacturing processes. These concerted efforts aim to hasten the commercialization of all-solid-state batteries. In the event of successful commercialization, the U.S.-Korea team will be able to capture the market for solid-state electrolytes, a key component of all-solid-state batteries, in the U.S., one of the largest consumers of secondary batteries such as ESS(Energy Storage System) and electric vehicles. "This work provides a new design principle for fluorine-substituted high-voltage stable chloride-based solid-state electrolytes, which will accelerate the commercialization of high-energy-density next-generation lithium all-solid-state batteries without fire hazards," said Dr. Seungho Yu of KIST. "This was a systematic, internationally collaborative study that provided computational science-based design principles for the development of a new solid-state electrolyte and validated them experimentally," said Dr. Brandon Wood of LLNL. [Figure 1] High-Voltage Stable Solid-State Electrolytes Design Strategies [Figure 2] Overview of KIST-LLNL International Cooperation Research ### 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 Jongho) through the KIST Major Project and Climate Change Response Technology Development Project, the Ministry of Trade, Industry and Energy (Minister Ahn Deokgeun) through the Lithium-based Next Generation Secondary Battery Performance Improvement and Manufacturing Technology Development Project, and the Automotive Industry Core Technology Development Project. The research was published in the latest issue of ACS Energy Letters (IF 22.0, top 3.6% in JCR), an international journal in the field of energy materials. Journal : ACS Energy Letters Title : Fluorine-Substituted Lithium Chloride Solid Electrolytes for High-Voltage All-Solid-State Lithium-Ion Batteries Publication Date : 2024.01.12. DOI : https://doi.org/10.1021/acsenergylett.3c02307
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- WriterDr. Yu Seungho
- 작성일2024.02.07
- Views397
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Development of eco-friendly and low-energy self-regenerative fiber material to recover valuable metals from industrial w
- Development of fiber-based adsorbent material to recover valuable metals from industrial wastewater - Minimize toxic chemicals and energy use by eliminating the need to replace and regenerate materials Technology to recover valuable metals from wastewater generated in various industries such as plating, semiconductors, automobiles, batteries, and renewable energy is important not only for environmental protection but also for economic reasons. In Korea, chemicals are mainly added to wastewater to precipitate heavy metal ions in the form of oxides, but accidents such as leakage of hazardous chemicals have occurred one after another, so it is necessary to develop more eco-friendly technologies. Against this backdrop, the Korea Institute of Science and Technology (KIST) announced that Dr. Jae-Woo Choi's team at the Water Resource Cycle Research Center has developed a fiber-like metal recovery material that can recover metal ions in water by adsorbing and crystallizing the metal, and the recovered metal crystals can desorb and regenerate themselves. KIST research team has developed a semi-permanent adsorption material by utilizing the phenomenon that metal ions in water crystallize when certain chemical functional groups are fixed on the surface of a fiber-like material and introducing a technology to remove the formed crystals. When tested with copper ions, the maximum adsorption amount of existing adsorbents is only about 1,060 mg/g, but by utilizing the developed material, near-infinite adsorption performance can be secured. In addition, existing high-performance adsorbents are in the form of small granules with diameters ranging from a few nanometers to tens of micrometers, making it difficult to utilize them underwater, but the metal recovery material developed by the KIST research team is in the form of fibers, making it easy to control underwater, making it easy to apply to actual metal recovery processes. “Since the developed material is based on acrylic fibers, it is not only possible to mass produce it through a wet spinning process, but also to utilize waste clothing,” said Dr. Jae-woo Choi of KIST. “The wastewater recycling technology will help reduce the industry's dependence on overseas sources of valuable metals that are in high demand.” [Fig 1] Structure and concept of SRF (a) Schematic illustration of fabricating PAN/PMMA fibers using a dry-jet wet spinning machine. The diameter of the PAN/PMMA fiber was readily controlled by regulating the injection rate and rolling speed. Information on the diameter of the fibers is summarized in table S1. Illustrations representing the physicochemical structure of (b) the PAN/PMMA fiber and (c) the SRF. (d) A series of courses for self-regeneration in which crystal layers are repetitively formed-detached on an SRF surface. The heavy metal ions and counter-anions induced nuclei for crystal growth, resulting in the formation of crystal layers. The crystal layers are self-detached from the SRF surfacevia collisions with each other, non-sticky surfaces, and the curvature of the fiber, and new crystals grow on the SRF surface in which the crystal layers are detached. (e) SEM image of the SRFs immersed in 1,000 ppm copper nitrate solution for 1 h. The three self-detachment aspects of the copper crystal layer, i.e., collision between the crystal layers, a non-sticky surface, and curvature of the SRF, were observed. Scale bar: 100 μm (f) Snapshot images show the course of self-detachment of crystal layers from an SRF via (g) non-sticky surface formation, (h) collision, and (i) surfacecurvatureduring an elapsed time of 55 min (Ci of 100 ppm and no pH adjustment). Scale bar: 200 μm. [Fig 2] Analysis of the self-detachment of crystal layers on the SRF surface. (a) Defect regions, which are negligibly narrow compared to the size of the crystal layers, cause the non-sticky SRF surface. (b) It also accelerates the detachment of the crystal layers by an elastic restoring force against the curvature of the SRF. (c) The dominant detachment phenomenon of crystal layers around the critical defect area is a collision between the crystal layers, accompanied by divergence or convergence depending on their angle and position. (d) When the defect region is larger than the size of the crystal layers, the growth of the crystal layers is terminated. FEG-SEM images show the self-detaching phenomena of the copper crystal layers from the SRF surface. (e) Self-detachment by the non-sticky surface, (f) the curvature of fiber, (g) and the divergence (inset scale bar: 1 μm) and (h) the convergence of crystal layers. (i) Termination of crystal growth. The purple region expressed on the fiber to distinguish it from the heavy metal crystal layer formed on the SRF surface represents wide defect regions where the crystal layer is not formed. Commonly, new crystals grow on the SRF surface after the existing crystal layer is self-detached. Scale bar: 50 μm. (j) XRD pattern of the SRF including crystals grown from the adsorbed Cu2+. It is matched well with that of a Cu2(NO3)(OH)3 polycrystal (ICDD No.01-075-1779). (k) SEM image of the Cu2+ crystal layers separated from the SRF surface exhibits a form similar to the curved surface of SRF. Scalebar: 200μm. (l) HR-TEM image of the Cu2+ crystal layer displays d-spacing values that match well with the XRD pattern. Scalebar: 10nm. [Fig 3] A heavy metal recovery module packed with the SRF. (a) Representative illustration of the module packed with the SRF for continuous recovery of heavy metals. The recovery module includes an upper part, in which the SRF is filled and is connected to the inlet and outlet pipes of the heavy metal solution, and a lower space, in which crystals of the heavy metal resources self-detached from the SRF surface can be concentrated by a density difference. (b) Actual photographs of the module packed with the SRF. (c) The heavy metal ions are crystallized on the surface of the SRF fiber. Scale bar: 500 μm. (d) Actual photographs of the module packed with the SRF during the injection of copper nitrate solution for 5h. (e) The heavy-metal crystal layers are self-detached and gathered at the bottom of the module. Scale bar: 200 μm. (f) A constant weight of crystal layers for heavy metals could be recovered during continuous injection of 100 L of copper nitrate solution with 100 ppm concentration into the module, packed with 5 g of SRF at a flow rate of 0.2 L/min. (g) Deconvoluted XPS peaks of N 1s on the SRF with different immersing times in the copper nitrate solution: 0, 1, 5, 10, 20, and 50 h. ### 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, funded by the Ministry of Science and ICT (Minister Jong-ho Lee) through the Leading Project for Material Innovation (2020M3H4A3106366), Sejong Science Fellowship (RS-2023-00209565), and KIST Institutional Unique Project (2E32442), was published on October 16, 2023 in the international journal Advanced Fiber Materials. Journal : Advanced Fiber Materials Title : A Self-Regenerable Fiber Sloughing Its Heavy Metal Skin for Ultra-High Separation Capability Publication Date : 2023.10.16. DOI : https://doi.org/10.1007/s42765-023-00333-0
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- WriterDr. Choi, Jae-Woo
- 작성일2024.02.06
- Views221
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Developing thermal radiation controllable epsilon-near-zero material that can withstand extreme environments
- Unlike conventional refractory conductimaterials, it not oxidizeand maintains performance at temperatures up to 1,000°C in air - Expected to be used in a wide range of extreme environments, including space, aerospace and thermophotovoltaic(TPV) system. Thermal radiation is electromagnetic radiation emitted by all objects with temperature and most representatively, there is the solar radiation spectrum that enters the Earth and causes the greenhouse effect. Controlling and utilizing the thermal radiation energy emitted from solar power, thermal power generation, and residual heat in industrial sites can reduce the cost of electricity production. Therefore, interest in radiation spectrum controlling technology is increasing in areas such as cooling, heat dissipation, and energy production. Until now, radiation spectrum control technology has been mainly used in general environmental conditions, but recently, materials that can withstand extreme environments such as space, aviation and TPV system are needed. Korea Institute of Science and Technology (KIST) announced that a team led by senior researcher Jongbum Kim at the Nanophotonics Research Center has developed a refractory material for controlling thermal radiation spectrum that maintains optical properties even at high temperatures of 1,000°C in air atmosphere and strong ultraviolet illumination. The team fabricated lanthanum-doped barium stannate oxide ("LBSO") as a nanoscale thin film with no lattice strain by pulsed laser deposition. Unlike conventional refractory conducting materials such as tungsten, nickel, and titanium nitride, which are easily oxidized at high temperatures, the LBSO material maintained its performance even when exposed to high temperatures of 1,000°C and intense ultraviolet light of 9 MW/cm2. The researchers then fabricated a thermal emitter based on a multilayer structure with high spectral selectivity in the infrared band using LBSO, and found that the multilayer structure was stable to heat and light as with the single layer thin film, confirming its applicability to TPV power generation technology. The LBSO material allows thermal radiation to be transferred to the PV cell without any additional methods to prevent it from oxidizing in contact with air. "As an alternative to solar and wind renewable energy, whose electricity production varies depending on the weather, eco-friendly thermoelectric power generation technology that uses radiant energy emitted by the Sun and high-temperature environments to generate electricity is gaining attention," said KIST senior researcher Jongbum Kim. "LBSO will contribute to addressing to climate change and the energy crisis by accelerating the commercialization of thermoelectric power generation." The researchers expect that LBSO can be applied not only to thermoelectric power generation technology and recycling of waste heat from industrial equipment, but also to technology for managing heat generated by exposure to and absorption of strong sunlight in extreme environments such as space and aviation, as it is highly resistant to UV exposure. [Fig 1] Schematic diagram of the application of LBSO thermal emitter in TPV energy conversion technology This diagram illustrates the effects of applying LBSO thermal emitter to TPV technology. In the case of a typical blackbody, when it absorbs heat, it emits radiant energy over a very broad wavelength range. However, this results in the emission of radiation energy at wavelengths that cannot be utilized by TPV cells, leading to reduced efficiency. By applying LBSO thermal emitters, it can selectively emit heat in the wavelength range where the TPV cells have the highest efficiency, increasing the overall energy generation efficiency. [Fig 2] Thermal durability of LBSO thin film and LBSO thermal emitter (Above) Changes in the crystal structure and optical properties of LBSO thin films before and after heat exposure. Metal oxides like ITO and AZO, which have similar properties with LBSO, exhibit changes in optical properties such as plasma frequency and damping coefficient when exposed to temperatures below 400 degrees. In contrast, LBSO maintains stable performance even up to 1000 degrees. (Below) Scanning electron microscope image and crystal structure of a multilayer structure including LBSO. The thermal emitter shows minimal changes in its characteristics when exposed to high temperatures and intense ultraviolet laser illumination in the air, as with the single layer. [Fig 3] Surface changes of LBSO thin films before and after heat treatment Surface changes of the thin film at various temperatures and laser intensities during heat exposure. It was observed that fine nanostructures formed on the surface; however, it was experimentally confirmed that these particles did not affect the material's linear optical properties. Semiconductor materials absorb light with higher energy than their bandgap, and exposure to intense ultraviolet light can induce changes in material properties. However, experimental evidence shows that LBSO material remains unchanged in its characteristics even when exposed to intense UV excimer laser, strong enough for the thin film to be etched. ### 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 Jong-ho Lee) through the Information and Communication Technology Development Project and Standard Development Support Project (RS-2023-00223082) and the KIST Future Source Research Project, was published in the international journal Advanced Science (IF: 15.1, JCR(%): 6.2) was published on Nov. 23. Journal : Nature Communications Title : Perovskite Lanthanum-Doped Barium Stannate: A Refractory Near-Zero-Index Material for High-Temperature Energy Harvesting Systems Publication Date : 2023.11.23. DOI : https://doi.org/10.1002/advs.202302410
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- WriterDr. Kim, Jongbum
- 작성일2024.02.06
- Views221
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Enable distributed quantum sensors for simultaneous measurements in distant places
- Implementing a method for estimating spatially-distributed multiple parametersusing a small number of photons - Use quantum phenomena to enable distributed quantum sensors with precision beyond classical limits We've all had the experience of trying to get the exact time of a highly competitive concert ticket or class beforehand. If the time in Seoul and Busan is off by even a fraction of an hour, one will be less successful than the other. Sharing the exact time between distant locations is becoming increasingly important in all areas of our lives, including finance, telecommunications, security, and other fields that require improved accuracy and precision in sending and receiving data. The Korea Institute of Science and Technology (KIST) announced that Dr. Hyang-Tag Lim and his team at the Center for Quantum Information, in collaboration with leading domestic and international research institutes such as Chung-Ang University, the Korea Research Institute of Standards and Science (KRISS), the Agency for Defense Development (ADD), and the Oak Ridge National Laboratory (ORNL) in the United States, have succeeded in implementing a distributed quantum sensor that can measure multiple spatially-distributed physical quantities with high precision beyond the standard quantum limit with few resources. Quantum phenomena such as superposition and entanglement can be used to more precisely measure the time of different clocks in two distant spaces. Similarly, if you have two physical quantities, one in Seoul and one in Busan, you can share the entanglement state in Seoul and Busan and then measure the two physical quantities simultaneously with greater precision than if you measure the physical quantities in Seoul and Busan separately. There is an expectation that quantum sensors will enable ultra-precise measurements that are not possible with classical sensors, and 'distributed quantum sensors' are systems that can measure distributed multiple parameters over a large area with higher precision than conventional sensors. The KIST research team has experimentally demonstrated that distributed quantum sensing systems can be used to measure phenomena with the highest precision achievable with quantum mechanics in situations where the objects to be measured are distributed over a large area. The team experimentally generated a superposed maximum entanglement state that simultaneously exists in four spaces far apart from the Bell state, a quantum entanglement state, and applied it to reach the Heisenberg limit, the limit of quantum mechanical precision. "We look forward to expanding into practical technologies such as global time synchronization and ultra-microscopic cancer detection by pioneering the core source technology for distributed quantum sensing, which enables measurements beyond the standard quantum limit with few resources," said Dr. Hyang-Tag Lim of KIST, who led the study. KIST conducts open R&D projects to secure world-class source technologies in quantum applications, including quantum sensors, and disseminate them to industry, and is working with various researchers from industry, academia, and research centers, including first author Seongjin Hong, a professor at Chung-Ang University. [Fig 1] Distributed quantum sensing Send quantum states from a centralized location to each node distributed over a large area to obtain an average of the phases. ### 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, which was supported by the Ministry of Science and ICT (Minister Lee Jong-ho) through the KIST Major Project (2E32241) and the Information and Communication Technology Planning and Evaluation Institute (IITP) Quantum Sensor Core Strategic Technology Development Project (RS-2023-0022863), was published on January 11 in the international journal Nature Communications (IF: 16.6, JCR(%) 7.5). on January 11th. Journal : Nature Communications Title : Distributed quantum sensing of multiple phases with fewer photons Publication Date : 2024.01.11. DOI : https://doi.org/10.1038/s41467-023-44204-z
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- WriterDr. Lim, Hyang-tag
- 작성일2024.02.06
- Views133
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Key LiDAR sensor elements for autonomous vehicles are now made with our technology
- High-performance sensor devices for short- and mid-range LiDAR applications - Expected to localize LiDAR sensor devices by developing based on a semiconductor mass production process LiDAR sensors are indispensable for the realization of advanced technologies such as advanced driver assistance systems (ADAS), autonomous driving, and AR/VR. In particular, short- and mid-range LiDAR used in AR/VR devices and smartphones requires better distance (depth) resolution to detect the shape of a person or object more accurately, and so a single-photon detector with better timing jitter performance is required. LiDAR measures distance and creates a 3D image by calculating the time it takes for a photon emitted by the transmitter to strike an object, reflect, and arrive back at the receiver. The slight difference in detection time that occurs when the single-photon detector at the receiver converts the light signal into an electrical signal is called "timing jitter," and the smaller the value of this jitter, the more accurately the object can be recognized. The Korea Institute of Science and Technology (KIST) announced that a team led by Dr. Myung-Jae Lee at the Post-Silicon Semiconductor Institute has developed a "single-photon avalanche diode (SPAD)" that can identify objects at the mm level based on a 40nm back-illuminated CMOS image sensor process. SPADs, which are ultra-high-performance sensor devices that can detect single photons, are extremely difficult to develop, and to date, only Sony of Japan has successfully commercialized SPAD-based LiDAR based on its 90nm back-illuminated CMOS image sensor process and supplied it to Apple products. Sony's SPAD shows better efficiency than back-illuminated SPADs reported in the literature, but its timing-jitter performance of about 137~222ps is insufficient to realize user discrimination, gesture recognition, and accurate shape recognition of objects required in short- and mid-range LiDAR applications. The single-photon sensor element developed by KIST has significantly improved the timing-jitter performance by more than two times to 56 ps, and the distance resolution has also been improved to about 8 mm, which has great potential for utilization as a short and mid-range LiDAR sensor element. In particular, since the SPAD was developed based on the 40nm back-illuminated CMOS image sensor process, a semiconductor process for mass production, through joint research with SK hynix, it is expected to be immediately localized and commercialized. "If commercialized as a core source technology for semiconductor LiDAR and 3D image sensors, it will greatly enhance our competitiveness in next-generation system semiconductors, which are Korea's strategic industries," said Myung-Jae Lee, principal investigator at KIST. [Fig 1] Simplified cross-section of a single-photon avalanche diode KIST single-photon avalanche diode developed in SK hynix's 40 nm back-illuminated CMOS image sensor technology [Fig 2] Semiconductor chip with ultra-high-performance sensor elements developed by Dr. Myung-Jae Lee's research team at KIST's Advanced Semiconductor Devices and Systems Laboratory (ADS Lab) [Fig 3] Dr. Myung-Jae Lee’s research team, Post-Silicon Semiconductor Institute, KIST (ADS Lab) ### 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, supported by the Korea Institute of Science and Technology (KIST) Institution Program (Grant No. 2E32242) and the National Research Foundation of Korea (NRF) (Grant No. 2021M3D1A2046731), was presented on December 12 at the International Electron Devices Meeting 2023 (IEDM 2023), held from December 9 to 13 in San Francisco, USA. IEDM is one of the most prestigious conferences for semiconductor industry and research experts, including major global semiconductor companies such as SK hynix, Samsung Electronics, and Intel.
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- WriterDr. Lee, Myung-Jae
- 작성일2024.02.06
- Views127
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Implement artificial neural network hardware systems by stacking them like "neuron-synapse-neuron" structural blocks.
- Implementing the 'neuron-synapse-neuron' basic unit structure in hardware for high-performance, low-power neuromorphic computing - Same material, same structure for processability and network scalability With the emergence of new industries such as artificial intelligence, the Internet of Things, and machine learning, the world's leading companies are focusing on developing next-generation artificial intelligence semiconductors that can process vast amounts of data while consuming energy efficiently. Neuromorphic computing, inspired by the human brain, is one of them. As a result, devices that mimic biological neurons and synapses are being developed one after another based on emerging materials and structures, but research on integrating individual devices into a system to verify and optimize them is still lacking. In order for large-scale artificial neural network hardware to become practical in the future, it is essential to integrate artificial neuron and synaptic devices, and it is necessary to reduce mass production costs and energy usage by fabricating devices with the same materials and structures. A team led by Dr. Joon Young Kwak of the Center for Neuromorphic Engineering at the Korea Institute of Science and Technology (KIST) announced that they have implemented an integrated element technology for artificial neuromorphic devices that can connect neurons and synapses like "Lego blocks" to construct large-scale artificial neural network hardware. The team fabricated vertically stacked memristor devices using hBN, a two-dimensional material that is advantageous for high integration and ultra-low power implementation, to demonstrate biological neurons and synapses characteristics. Since the team designed artificial neuron and synaptic devices with the same material and the same structure, unlike conventional silicon CMOS-based artificial neural imitation devices with complex structures using multiple devices, the devices developed by the team have secured ease of process and network scalability, paving the way for the development of large-scale artificial neural network hardware. By integrating and connecting the developed devices, the team also successfully implemented the "neuron-synapse-neuron" structure, the basic unit block of an artificial neural network, in hardware to demonstrate spike signal-based information transmission, which is how the human brain works. By experimentally verifying that the modulation of spike signal information between two neurons can be adjusted according to the synaptic weights of the artificial synaptic device, the researchers showed the potential of using hBN-based emerging devices for low-power, large-scale AI hardware systems. "Artificial neural network hardware systems can be used to efficiently process vast amounts of data generated in real-life applications such as smart cities, healthcare, next-generation communications, weather forecasting, and autonomous vehicles," said KIST's Dr. Joon Young Kwak, explaining the significance of the research achievement. "It will help improve environmental issues such as carbon emissions by significantly reducing energy usage while exceeding the scaling limits of existing silicon CMOS-based devices." [Fig 1] Experimental results of modulating the connection strength of front and back neurons by synaptic weights. (a) Schematic diagram of a biological neural network and (b) circuit schematic of an artificial neural network implemented in hardware using an artificial neuromorphic device. (c) Experimental results of the change in connection strength between two neurons as the synaptic weight changes. It is observed that the degree of firing of the downstream neuron decreases as the synaptic weight decreases. [Fig 2] Two-dimensional material-based volatile and nonvolatile memory devices (a) Schematic representation of two-dimensional material-based volatile and non-volatile memory devices (top) and measured electrical properties of fabricated devices (bottom); (b) Electron micrographs (top) and transmission electron micrographs (bottom) of fabricated devices. Utilizing fabricated devices to emulate biological neuron and synapse properties. ### 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 funded by the Ministry of Science and ICT (Minister Jong-Ho Lee)'s Next Generation Intelligent Semiconductor Technology Development (Device) Project (2021M3F3A2A01037738) and KIST's Institutional Program and was published in the international journal Advanced Functional Materials (IF: 19.0, JCR(%): 4.2) online on November 5. Journal : Advanced Functional Materials Title : Hardware Implementation of Network Connectivity Relationships Using 2D hBN-Based Artificial Neuron and Synaptic Devices Publication Date : 2023.11.05. DOI : https://doi.org/10.1002/adfm.202309058
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- WriterDr. Kwak, Joon Young
- 작성일2024.02.06
- Views286
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Development of real-time trace hydrogen gas leakage via a novel terahertz-wave optical platform
- Novel approach for real-time detection of ultra-low levels of hydrogen gas leakageusing palladium materials embedded in Terahertz Metamaterials. - Successfully elucidation of underlying mechanism of metal-light interaction during a genesis of nano-water film Hydrogen gas is the smallest and lightest of all known molecules, and its colorless and odorless nature makes it easy to leak. Also when concentrated above 4% in a confined space, it poses a risk of ignition or explosion. In order for hydrogen to become a major player in the future energy industry, it is essential to ensure the safety issues via ultra-sensitive gas detection technology over the entire gas-dealing processes such as gas production, storage, and transportation. However, conventional gas-leakage sensors using electric signals are prone to yield electrical sparks, which can cause an explosion of leaked hydrogen gas. In addition, the mainstream electrode-based contact sensors affect the effective signal stability depending on the device's contact state showing weak signal fidelity. Thus, it is desirable for achieving stable, non-explosive via non-contact mode detection for removing any possible dangers have been spiring to develop a secure device that does not lead to disaster situations. The Korea Institute of Science and Technology (KIST) announced that a team led by Dr. Minah Seo of the Sensor Systems Research Center & KU-KIST Graduate School and Prof. Yong-Sang Ryu of School of Biomedical Engineering, College of Health Sciences, Korea University, has developed a non-contact terahertz light sensor. This can detect hydrogen gas leaks as small as 0.25% in real-world environments at room temperature and pressure, which is the world-top level of limit-of-detection performance via optical detection methods. Spectroscopy is the non-contact observation method measuring changes in the value of optical constants of an analytic sample. In this method, changes in the reacting substance are observed non-invasively, by measuring variations in the optical properties when the reacting substance encounters hydrogen gas. Terahertz electromagnetic waves have a very wide frequency band, which makes them sensitive to the natural vibrations of gas molecules, and can be utilized in spectroscopy to resolve minute unique information and differences in molecules such as various gases, DNA, and amino acids. However, due to the low probability of interaction with trace amounts of hydrogen gas and the lack of technology to amplify the signal of terahertz waves, it has been difficult to utilize in practice. The research team focused on the property of hydrogen permeating into palladium metal, and devised a research strategy to address this through the interaction of light and matter. The researchers developed a gas-detection sensing platform that can sensitively measure changes in terahertz optical signals caused by trace amounts of gas using metamaterials that have the ability to amplify signals in specific bands of electromagnetic waves. The team first developed a terahertz metamaterial that can amplify signals in the gas-sensitive terahertz band, and then uniformly applied palladium to the metamaterial to create an extremely narrow 14 nm space to maximize the sensitivity of the terahertz signal. The palladium plays bifunctional roles in not only the catalytic reaction of adsorbed hydrogen and oxygen to produce water molecules on the surface, but also in the hydrogen storage. For mimicry of real-world environments (80 % of Nitrogen, 20 % of Oxygen), Hydrogen and oxygen gases were then injected into the developed sensing chamber and exposed to the terahertz sensing platform. The results showed great responsibility with respect to exposed hydrogen gas via significant optical signal variation, and these were scientifically analyzed in a real-time fashion. The usage of ultra-thin palladium together with ultra-sensitive optical band width (the terahertz) provided synergetic performance enabling to detect under 1% of hydrogen gas leakage to the real-time detection level. Not only for the superior detection performance, but also the reusability of the detection platforms was considered during platform designing process. In general, metal hydrides such as palladium are difficult to reuse because they are irreversible, meaning they cannot return to their original state after a phase change, but the KIST-Korea University research team secured the reusability of the sample through special processing technology. They also succeeded in developing a technology to contactlessly track the mechanism of hydrogen desorption at the nanometer scale in real time through optical signals. "Existing light sensors have very limited reliability in normal temperature, pressure, and humidity environments, but this is a promising technology that can detect and screen not only gases but also various biochemical substances in extremely small amounts by dramatically increasing sensitivity," said Dr. Minah Seo, lead author of the study. "It is expected to be used to develop a system that can immediately respond to various harmful factors, gases, and diseases through mobile, on-site, and real-time inspections." "In addition to the terahertz measurement technology, it has opened up the possibility of visually checking various gas adsorption and desorption processes and molecular-level chemical reaction mechanisms occurring on metal surfaces," said Professor Ryu Yong-sang of Korea University, lead author of the study. [Fig 1] Observe the metastructure and optical constants of the palladium-catalyzed reaction as a function of the concentration ratio of hydrogen and oxygen, the thickness of the resulting water layer, and the resulting terahertz signal changes. ### 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 KIST Major Project, the National Research Foundation of Korea (No. 2023R1A2C2003898 , and 2021R1A2C2009236) from the Ministry of Science and ICT (Minister Lee Jong-ho), the KIST Major Project, the KU-KIST School Program of Korea University, and the Korea University Intramural Project, and the results were published online on November 23 in the international journal Advanced Materials (IF 29.4, JCR 2.2%). Journal : Advanced Materials Title : Advancements in intense terahertz field focusing over metallic nanoarchitectures for monitoring hidden interatomic gas-matter interactions Publication Date : 2023.11.23. DOI : https://doi.org/10.1002/adma.202308975
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- WriterDr. Seo, Minah
- 작성일2024.02.06
- Views107
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Advanced Full-color image sensor technology enabling simultaneous energy harvesting and imaging
- Single-pixel imaging successfully achieved for the first time using an organic-based photoelectric photodetector - Energy-efficient imaging in low-light conditions, facilitating human-computer interaction, shows promise for application in smart indoor environments Organic-based optoelectronic technology is increasingly recognized as an energy-efficient solution for low-power indoor electronics and wireless IoT sensors. This is largely due to its superior flexibility and light weight compared to conventional silicon-based devices. Notably, organic photovoltaic cells (OPVs) and organic photodetectors (OPDs) are leading examples in this field. OPVs have the remarkable ability to absorb energy and generate electricity even under very low light condition, while OPDs are capable of capturing images. However, despite their potential, the development of these devices has been conducted independently thus far. As a result, they have not yet reached the level of efficiency necessary to be considered practical for next-generation, miniaturized devices. The Korea Institute of Science and Technology (KIST), led by Dr. Min-Chul Park and Dr. Do Kyung Hwang of the Center for Opto-Electronic Materials and Devices, Prof. Jae Won Shim and Prof. Tae Geun Kim of the School of Electrical Engineering at Korea University, Prof. JaeHong Park of the Department of Chemistry and Nanoscience at Ewha Womans University, have developed an organic-based optoelcectronic device. This innovative device not only integrates the functionalities of organic photovoltaic cells (OPVs) and organic photodetectors (OPDs) but also pioneers in visualizing images in applications requiring low-light conditions, thereby enhancing energy efficiency in indoor environments. By advancing the organic semiconductor layer into a multicomponent structure, the research team has enhanced the device's performance. In door environments, it achieves an impressive photoelectric conversion efficiency exceeding 32%, along with a linear dynamic range surpassing 130 dB. This significant improvement in contrast ratio, especially in low-light conditions, allows for a much clearer image than conventional silicon devices, which typically offer a linear dynamic range of 100 dB. The collaborative research team made further strides by successfully applying single-pixel image sensing. This image sensing system capture ambient light, transforms into electrical energy, and utilize this energy to acquire images. In contrast to the previous need for specialized cameras in low-light of standard lighting conditions, the newly developed photodetector, featuring a multi-component semiconductor layer, offers a versatile application. It can function not only as a conventional camera but also as a decorative element on windows or walls, providing sufficient resolution to discern shapes and movements of objects. Dr. Min-chul Park from KIST highlighted the versatility of this technology, noting, "While primarily functioning as an energy harvester, it can also be applied to detect movement and recognize motion patterns in environments without light." He further expressed optimism about its potential applications, stating, "This holds great promise not only for human-computer interaction (HCI) research but also in various industrial sectors, including smart indoor environments." [Fig 1] Dual-function integrated image sensor Organics-based optoelectronic technology is gaining attention as an energy-efficient and environmentally friendly electronic device for Internet of Things (IoT)-based wireless sensors and low-power indoor electronics. Among them, organic photovoltaic (OPV) and organic photodetector (OPD) efficiently utilize ambient unutilized or low-light to generate electricity and detect light to implement images. Organic photovoltaics (OPVs) can be used to harvest indoor energy, while organic photodetectors (OPDs) can be used like cameras, utilizing indoor light for imaging as needed. ### 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) as a KIST Institutional Program, a mid-career research support project of the Korea Research Foundation, and a Leader Research Project, and the results have been published in the international journal Advanced Materials (IF: 29.4, JCR(%): 2.312) and published online on November 2023. Journal : Advanced Materials Title : Self-Powering Sensory Device with Multi-Spectrum Image Realization for Smart Indoor Environments Publication Date : 2023.11.16. DOI : https://doi.org/10.1002/adma.202307523
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- WriterDr. Park, Min-chul, Dr. Hwang, Do Kyung
- 작성일2024.02.05
- Views121