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KAIST Directly Visualizes the Hidden Spatial Order of Electrons in a Quantum Material
<(Back row, from left) Yeongkwan Kim, SungBin Lee, Heejun Yang, Yongsoo Yang_(Front row, from left) Jemin Park, Seokjo Hong, Jaewhan Oh>
· Cryogenic 4D-STEM reveals how charge density waves form, fragment, and persist across a phase transition
· First direct measurement of electronic amplitude correlations uncovers strain-driven inhomogeneity and localized order above the transition temperature
Electronic order in quantum materials often emerges not uniformly, but through subtle and complex patterns that vary from place to place. One prominent example is the charge density wave (CDW), an ordered state in which electrons arrange themselves into periodic patterns at low temperatures. Although CDWs have been studied for decades, how their strength and spatial coherence evolve across a phase transition has remained largely inaccessible experimentally.
Now, a team led by Professor Yongsoo Yang of the Department of Physics at KAIST (Korea Advanced Institute of Science and Technology), together with Professors SungBin Lee, Heejun Yang, and Yeongkwan Kim, and in collaboration with Stanford University, has for the first time directly visualized the spatial evolution of charge density wave amplitude order inside a quantum material.
A New Way to See Electronic Order at the Nanoscale
Using a liquid-helium-cooled electron microscope setup combined with four-dimensional scanning transmission electron microscopy (4D-STEM), the researchers mapped how CDW order develops, weakens, and fragments as temperature changes. This approach allowed them to reconstruct nanoscale maps of the CDW amplitude, revealing not just whether the order exists, but how strong it is and how it is spatially connected.
This study is similar to filming the growth of ice crystals as water freezes using an ultra-high-magnification camera. In this case, however, the researchers observed electrons arranging themselves at cryogenic temperatures of around –253°C, and used an electron microscope capable of resolving features one hundred-thousandth the width of a human hair instead of a conventional camera. The results showed that the electronic patterns do not appear uniformly across the material. In some regions, clear patterns are visible, while in neighboring areas they are entirely absent, much like a lake that does not freeze all at once, with patches of ice interspersed with liquid water.
How Electronic Order Breaks Apart in Real Space
The team further demonstrated that this spatial inhomogeneity is closely linked to local strain inside the crystal. Even extremely small distortions that are far below optical resolution strongly suppress the CDW amplitude. This clear anticorrelation between strain and electronic order provides direct evidence that local lattice distortions play a decisive role in shaping CDW patterns.
Unexpectedly, the researchers also observed that localized regions of CDW order can persist even above the transition temperature, where long-range order is generally thought to disappear. These isolated pockets of electronic order suggest that the CDW transition is not a simple, uniform melting process, but instead involves gradual loss of spatial coherence.
A key advance of this work is the world’s first direct measurement of CDW amplitude correlations. By quantifying how the strength of electronic order at one location is related to that at another, the study reveals how CDW coherence collapses across the transition, while local amplitude remains finite. Such information could not be obtained with conventional diffraction or scanning probe techniques.
Toward a New Framework for Studying Electronic Order
Charge density waves are a central feature of many quantum materials and often coexist or compete with other electronic states. By directly accessing their spatial structure and correlations, this study provides a new experimental framework for understanding how collective electronic order forms and evolves in real materials.
Dr. Yongsoo Yang, who led the research, explained the significance of the results: “Until now, the spatial coherence of charge density waves was largely inferred indirectly. Our approach allows us to directly visualize how electronic order varies across space and temperature, and to identify the factors that locally stabilize or suppress it.”
[Figure 1] Schematic illustration of an experiment employing 4D-STEM to probe the spatial variations of charge density waves in the prototypical quantum material NbSe2 under a liquid-helium cryogenic environment (AI-generated image).
This research, with Seokjo Hong, Jaewhan Oh and Jemin Park of KAIST as co-first authors, was published online in Physical Review Letters on January 6th (Title: Spatial correlations of charge density wave order across the transition in 2H-NbSe2).
The study was mainly supported by the National Research Foundation of Korea (NRF) Grants (Individual Basic Research Program, Basic Research Laboratory Program, Nanomaterial Technology Development Program) funded by the Korean Government (MSIT).
2026.01.20 View 264 -
KAIST Proposes a Multinational AI Cooperation Strategy Beyond U.S.–China Dominance
2026.01.19 View 198 -
Playground for Future Quantum Technology: KAIST-MIT Quantum Information Winter School Successfully Concluded
< Group photo of the KAIST-MIT Quantum Information Winter School >
“Through the KAIST-MIT Quantum Information Winter School, I was able to view research from a broader perspective. The experience of collaborating with students from various universities and majors to complete a project was very refreshing,” said Jun-hyeong Cho, a student at the KAIST School of Electrical Engineering.
KAIST announced on the 16th that the Graduate School of Quantum Science and Technology successfully concluded the ‘KAIST-MIT Quantum Information Winter School,’ held jointly with the Massachusetts Institute of Technology (MIT) from January 5th to 16th at the KAIST main campus in Daejeon.
For this year’s Winter School, 50 junior and senior undergraduate students from Korea and abroad were selected to receive intensive training to grow into next-generation quantum talent. Eight world-renowned scholars from KAIST and MIT participated in the program, providing a multi-dimensional curriculum that spanned theory and practice—ranging from theoretical lectures and introductions to cutting-edge quantum experiments to visits to government-funded research institutes and student poster presentations.
Celebrating its third anniversary since its inception in 2024, the Winter School is now evaluated as a premier quantum information education program in Korea. Alongside KAIST faculty, world-class scholars from MIT participated directly in lectures and field training, operating an intensive curriculum that covered the entirety of quantum information science.
The lecturing faculty included world authorities in quantum computing, quantum devices, quantum machine learning, and quantum simulation, such as MIT professors Pablo Jarillo-Herrero, Seth Lloyd, Kevin P. O’Brien, and William D. Oliver, as well as KAIST scholars Jaewook Ahn, Joonwoo Bae, Gil-Young Cho, and Jae-yoon Choi.
Going beyond theoretical lectures, participants gained a broad understanding of research trends, technical limitations, and future development directions of state-of-the-art quantum technology through experimental training in core areas such as quantum computing, communication, sensing, and simulation.
< Scene from a Winter School lecture >
Furthermore, students visited the Korea Research Institute of Standards and Science (KRISS) and the Electronics and Telecommunications Research Institute (ETRI) to experience actual research sites, engaging in field-oriented education that bridges quantum theory and practice. The poster presentation session, where students shared their own research ideas, received enthusiastic responses as a forum for deep academic exchange, allowing students to receive direct feedback from MIT faculty.
Tae-hee Kim, a student from Pusan National University, remarked, “I was greatly inspired by the passion of the MIT faculty and the high level of questions from the students. It served as a motivation for me to pursue deeper studies independently.” Byung-jin Hwang, a student from Yonsei University, added, “I expected lectures from world-class scholars to be difficult, but I was impressed by the explanations tailored to the undergraduate level. The poster presentation session was particularly memorable.”
Eun-seong Kim, Dean of the KAIST Graduate School of Quantum Science and Technology, stated, “The KAIST-MIT Quantum Information Winter School is a special educational program where students can learn directly from world-renowned quantum researchers and experience cutting-edge research. We look forward to the active participation of future talents who will lead the quantum industry.”
Participants for this Winter School were selected through a document review process, and the program was operated entirely free of charge. KAIST covered all educational expenses and provided dormitory accommodations and lunch. Detailed information about the event can be found on the KAIST Graduate School of Quantum Science and Technology website (https://quantumschool.kaist.ac.kr/).
< Poster for the KAIST-MIT Quantum Information Winter School >
2026.01.16 View 253 -
Seeing Black Holes More Clearly with Laser Light
<(From Left) Researcher Junyong Choi, Researcher Woosong Jeong, Professor Jungwon Kim, Researcher Jihoon Baek >
Radio telescopes are instruments that capture faint radio signals from space and convert them into images of celestial bodies. To observe distant black holes clearly, multiple radio telescopes must capture cosmic signals at exactly the same time, acting as a single unit. Research teams at KAIST have developedr a new reference signal technology that uses laser light to precisely synchronize the observation timing and phase of these telescopes.
KAIST announced on January 15th that a research team led by Professor Jungwon Kim from the Department of Mechanical Engineering—in collaboration with the Korea Astronomy and Space Science Institute, the Korea Research Institute of Standards and Science, and the Max Planck Institute for Radio Astronomy (MPIfR) in Germany—has implemented a technology that directly applies optical frequency comb lasers to radio telescope receivers.
While a typical laser emits only one color (frequency), an optical frequency comb laser emits tens of thousands of extremely accurate colors arranged at regular intervals. This appearance resembles the teeth of a comb, hence the name "frequency comb." Since the frequency of each individual "tooth" is known exactly and the intervals can be precision-tuned to the level of an atomic clock, scientists refer to it as an "ultra-precision ruler made of light."
The core of Very Long Baseline Interferometry (VLBI), a technique where multiple radio telescopes observe simultaneously, is aligning the phases of the radio signals received by each telescope as if aligning them to a single precise ruler. However, existing electronic reference signal methods faced limitations; as observation frequencies increased, precise phase calibration is becoming more difficult.
In response, the KAIST research team developed a method to deliver the optical frequency comb laser directly into the radio telescope, based on the idea of "improving the fundamental precision of phase alignment by utilizing light (lasers) from the signal generation stage." Through this, they successfully solved the problems of reference signal generation and phase calibration simultaneously within a single optical system.
If the conventional method was like using a "ruler that makes phase alignment difficult" at higher frequencies, this new technology can be compared to setting a standard with an "ultra-precision ruler that fixes the phase with extremely stable light." As a result, they have laid the foundation for distant radio telescopes to interoperate as elaborately as one giant telescope.
This technology was verified through test observations at the Korea VLBI Network (KVN) Yonsei Radio Telescope. The research team succeeded in detecting stable interference patterns (fringes) between radio telescopes and proved through actual observation that precise phase calibration is possible. Recently, this system was also installed at the KVN SNU Pyeongchang Radio Telescope, leading to expanded experiments using multiple observation sites simultaneously.
The team expects that this will not only allow for clearer imaging of black holes but also drastically reduce phase delay errors between instruments—a long-standing issue in VLBI observations.
The applications of this technology are not limited to astronomical observations. The team anticipates that it can be expanded to various advanced fields requiring precise space-time measurements, such as▲ Intercontinental ultra-precision clock comparison ▲Space geodesy ▲Deep-space probe tracking
< Illustration of the system principle (Image generated by AI) >
Professor Jungwon Kim of KAIST stated, "This research is a case where the limits of existing electronic signal generation technology were overcome by directly applying optical frequency comb lasers to radio telescopes. It will significantly contribute to improving the precision of next-generation black hole observations and advancing the fields of frequency metrology and time standards."
Dr. Minji Hyun (currently at KRISS) and Dr. Changmin Ahn from KAIST participated as co-first authors. The research findings were published on January 4th in the international academic journal Light: Science & Applications.
Paper Title: Optical frequency comb integration in radio telescopes: advancing signal generation and phase calibration
DOI: 10.1038/s41377-025-02056-w
Lead Authors: Dr. Minji Hyun (KAIST, currently KRISS), Dr. Changmin Ahn (KAIST), Jungwon Kim (KAIST)
This research was conducted with support from the National Research Council of Science & Technology (NST) Creative Alliance Project(CAP), the National Research Foundation of Korea (NRF), and the Institute of Information & Communications Technology Planning & Evaluation (IITP).
2026.01.15 View 613 -
KAIST–Daekyo, Opening of the Cognitive Enhancement Research Center Lounge
< Group photo of officials at the opening ceremony of the KAIST–Daekyo Cognitive Enhancement Research Center Lounge >
KAIST held the opening ceremony for the ‘KAIST–Daekyo Cognitive Enhancement Research Center Lounge,’ jointly established with Daekyo, at the Meta-Convergence Hall on the Daejeon main campus last Saturday, the 10th.
This lounge was established through an in-kind donation by Daekyo for space creation as part of research cooperation. It was designed as a base space to more systematically operate brain development and cognitive function enhancement research that KAIST and Daekyo have been jointly promoting, and to share research results with society. Through this event, KAIST introduced the achievements of its research cooperation to date and provided a forum to explore the future directions of education and brain science.
Key KAIST officials, including Kyun Min Lee, Vice President for Provost and Academic Affairs, and Dae-Soo Kim, Dean of the College of Life Science and Bioengineering, as well as officials from both organizations, including Ho-joon Kang, CEO of Daekyo, attended the event to celebrate the opening of the lounge.
Since signing a Memorandum of Understanding (MOU) for industry-academic research cooperation with Daekyo in 2023, our university has been jointly conducting research on cognitive function enhancement and mental health across the entire life cycle—from infants to adults and seniors—based on brain and cognitive science. The cooperation continues to expand these research results into educational content and solutions.
An official from Daekyo stated, "The Cognitive Enhancement Research Center Lounge is a symbolic space for the research cooperation accumulated by both organizations, and it is highly meaningful to be able to communicate directly with customers and share research results here. Moving forward, Daekyo will continue to expand its cooperation with KAIST to prove the value of scientific and systematic education."
Kyun Min Lee, Vice President for Provost and Academic Affairs, said, "The opening of this lounge is significant in that a space for industry-academic cooperation research was created through Daekyo’s donation. Based on this space, KAIST will strive to share the achievements of brain and cognitive science research with society and contribute to the field of education."
2026.01.12 View 174 -
KAIST detects ‘hidden defects’ that degrade semiconductor performance with 1,000× higher sensitivity
<(From Left) Professor Byungha Shin, Ph.D candidate Chaeyoun Kim, Dr. Oki Gunawan>
Semiconductors are used in devices such as memory chips and solar cells, and within them may exist invisible defects that interfere with electrical flow. A joint research team has developed a new analysis method that can detect these “hidden defects” (electronic traps) with approximately 1,000 times higher sensitivity than existing techniques. The technology is expected to improve semiconductor performance and lifetime, while significantly reducing development time and costs by enabling precise identification of defect sources.
KAIST (President Kwang Hyung Lee) announced on January 8th that a joint research team led by Professor Byungha Shin of the Department of Materials Science and Engineering at KAIST and Dr. Oki Gunawan of the IBM T. J. Watson Research Center has developed a new measurement technique that can simultaneously analyze defects that hinder electrical transport (electronic traps) and charge carrier transport properties inside semiconductors.
Within semiconductors, electronic traps can exist that capture electrons and hinder their movement. When electrons are trapped, electrical current cannot flow smoothly, leading to leakage currents and degraded device performance. Therefore, accurately evaluating semiconductor performance requires determining how many electronic traps are present and how strongly they capture electrons.
The research team focused on Hall measurements, a technique that has long been used in semiconductor analysis. Hall measurements analyze electron motion using electric and magnetic fields. By adding controlled light illumination and temperature variation to this method, the team succeeded in extracting information that was difficult to obtain using conventional approaches.
Under weak illumination, newly generated electrons are first captured by electronic traps. As the light intensity is gradually increased, the traps become filled, and subsequently generated electrons begin to move freely. By analyzing this transition process, the researchers were able to precisely calculate the density and characteristics of electronic traps.
The greatest advantage of this method is that multiple types of information can be obtained simultaneously from a single measurement. It allows not only the evaluation of how fast electrons move, how long they survive, and how far they travel, but also the properties of traps that interfere with electron transport.
The team first validated the accuracy of the technique using silicon semiconductors and then applied it to perovskites, which are attracting attention as next-generation solar cell materials. As a result, they successfully detected extremely small quantities of electronic traps that were difficult to identify using existing methods—demonstrating a sensitivity approximately 1,000 times higher than that of conventional techniques.
< Conceptual Diagram of the Evolution of Hall Characterization (Analysis) Techniques >
Professor Byungha Shin stated, “This study presents a new method that enables simultaneous analysis of electrical transport and the factors that hinder it within semiconductors using a single measurement,” adding that “it will serve as an important tool for improving the performance and reliability of various semiconductor devices, including memory semiconductors and solar cells.”
The results of this research were published on January 1 in Science Advances, an international academic journal, with Chaeyoun Kim, a doctoral student in the Department of Materials Science and Engineering, as the first author.
※ Paper title: “Electronic trap detection with carrier-resolved photo-Hall effect,” DOI: https://doi.org/10.1126/sciadv.adz0460
This research was supported by the Ministry of Science and ICT and the National Research Foundation of Korea.
< Conceptual Diagram of Charge Transport and Trap Characterization Using Photo-Hall Measurements (AI-generated image) >
2026.01.08 View 594 -
Breaking Performance Barriers of All Solid State Batteries
< (Bottom, from left) Professor Dong-Hwa Seo, Researcher Jae-Seung Kim, (Top, from left) Professor Kyung-Wan Nam, Professor Sung-Kyun Jung, Professor Youn-Seok Jung >
Batteries are an essential technology in modern society, powering smartphones and electric vehicles, yet they face limitations such as fire explosion risks and high costs. While all-solid-state batteries have garnered attention as a viable alternative, it has been difficult to simultaneously satisfy safety, performance, and cost. Recently, a Korean research team successfully improved the performance of all-solid-state batteries simply through structural design—without adding expensive metals.
KAIST announced on January 7th that a research team led by Professor Dong-Hwa Seo from the Department of Materials Science and Engineering, in collaboration with teams led by Professor Sung-Kyun Jung (Seoul National University), Professor Youn-Suk Jung (Yonsei University), and Professor Kyung-Wan Nam (Dongguk University), has developed a design method for core materials for all-solid-state batteries that uses low-cost raw materials while ensuring high performance and low risk of fire or explosion.
Conventional batteries rely on lithium ions moving through a liquid electrolyte. In contrast, all-solid-state batteries use a solid electrolyte. While this makes them safer, achieving rapid lithium-ion movement within a solid has typically required expensive metals or complex manufacturing processes.
To create efficient pathways for lithium-ion transport within the solid electrolyte, the research team focused on "divalent anions" such as oxygen and sulfur . Divalent anions play a crucial role in altering the crystal structure by integrating into the basic framework of the electrolyte.
The team developed a technology to precisely control the internal structure of low-cost zirconium (Zr)-based halide solid electrolytes by introducing these divalent anions. This design principle, termed the "Framework Regulation Mechanism," widens the pathways for lithium ions and lowers the energy barriers they encounter during transport. By adjusting the bonding environment and crystal structure around the lithium ions, the team enabled faster and easier movement.
To verify these structural changes, the researchers utilized various high-precision analysis techniques, including:
High-energy Synchrontron X-ray diffraction(Synchrotron XRD)
Pair Distribution Function (PDF) analysis
X-ray Absorption Spectroscopy (XAS)
Density Functional Theory (DFT) modeling for electronic structure and diffusion.
The results showed that electrolytes incorporating oxygen or sulfur improved lithium-ion mobility by 2 to 4 times compared to conventional zirconium-based electrolytes. This signifies that performance levels suitable for practical all-solid-state battery applications can be achieved using inexpensive materials.
Specifically, the ionic conductivity at room temperature was measured at approximately 1.78 mS/cm for the oxygen-doped electrolyte and 1.01 mS/cm for the sulfur-doped electrolyte. Ionic conductivity indicates how quickly and smoothly lithium ions move; a value above 1 mS/cm is generally considered sufficient for practical battery applications at room temperature.
< Structural Regulation Mechanism of Zr-based Halide Electrolytes via Divalent Anion Introduction >
< Atomic Rearrangement of Solid Electrolyte for All-Solid-State Batteries (AI-generated image) >
Professor Dong-Hwa Seo stated, "Through this research, we have presented a design principle that can simultaneously improve the cost and performance of all-solid-state batteries using cheap raw materials. Its potential for industrial application is very high." Lead author Jae-Seung Kim added that the study shifts the focus from "what materials to use" to "how to design them" in the development of battery materials.
This study, with Jae-Seung Kim (KAIST) and Da-Seul Han (Dongguk University) as co-first authors, was published in the international journal Nature Communications on November 27, 2025.
Paper Title: Divalent anion-driven framework regulation in Zr-based halide solid electrolytes for all-solid-state batteries
DOI: https://www.nature.com/articles/s41467-025-65702-2
This research was supported by the Samsung Electronics Future Technology Promotion Center, the National Research Foundation of Korea, and the National Supercomputing Center.
2026.01.07 View 1300 -
KAIST Solves Key Commercialization Challenges of Next-Generation Anode-Free Lithium Batteries
<(From Left) Ph.D candidate Juhyun Lee, Postdoctoral Researcher Jinuk Kim, (Upper Right) Professor Jinwoo Lee>
Anode-free lithium metal batteries, which have attracted attention as candidates for electric vehicles, drones, and next-generation high-performance batteries, offer much higher energy density than conventional lithium-ion batteries. However, their short lifespan has made commercialization difficult. KAIST researchers have now moved beyond conventional approaches that required repeatedly changing electrolytes and have succeeded in dramatically extending battery life through electrode surface design alone.
KAIST (President Kwang Hyung Lee) announced on the 4th of January that a research team led by Professors Jinwoo Lee and Sung Gap Im of the Department of Chemical and Biomolecular Engineering fundamentally resolved the issue of interfacial instability—the greatest weakness of anode-free lithium metal batteries—by introducing an ultrathin artificial polymer layer with a thickness of 15 nanometers (nm) on the electrode surface.
Anode-free lithium metal batteries have a simple structure that uses only a copper current collector instead of graphite or lithium metal at the anode. This design offers advantages such as 30–50% higher energy density compared to conventional lithium-ion batteries, lower manufacturing costs, and simplified processes. However, during the initial charging process, lithium deposits directly onto the copper surface, rapidly consuming the electrolyte and forming an unstable solid electrolyte interphase (SEI), which leads to a sharp reduction in battery lifespan.
Rather than changing the electrolyte composition, the research team chose a strategy of redesigning the electrode surface where the problem originates. By forming a uniform ultrathin polymer layer on the copper current collector using an iCVD (initiated chemical vapor deposition) process, they found that this layer regulates interactions with the electrolyte, precisely controlling lithium-ion transport and electrolyte decomposition pathways.
<Figure 1. Schematic of an ultrathin artificial polymer layer (15 nm thick) introduced onto the electrode surface>
In conventional batteries, electrolyte solvents decompose to form soft and unstable organic SEI layers, causing non-uniform lithium deposition and promoting the growth of sharp, needle-like dendrites. In contrast, the polymer layer developed in this study does not readily mix with the electrolyte solvent, inducing the decomposition of salt components rather than solvents. As a result, a rigid and stable inorganic SEI is formed, simultaneously suppressing electrolyte consumption and excessive SEI growth.
Using operando Raman spectroscopy and molecular dynamics (MD) simulations, the researchers identified the mechanism by which an anion-rich environment forms at the electrode surface during battery operation, leading to the formation of a stable inorganic SEI.
This technology requires only the addition of a thin surface layer without altering electrolyte composition, offering high compatibility with existing manufacturing processes and minimal cost burden. In particular, the iCVD process enables large-area, continuous roll-to-roll production, making it suitable for industrial-scale mass production beyond the laboratory.
<Figure 2. Design rationale of the current collector-modifying artificial polymer layer and the SEI formation mechanism>
Professor Jinwoo Lee stated, “Beyond developing new materials, this study is significant in that it presents a design principle showing how electrolyte reactions and interfacial stability can be controlled through electrode surface engineering,” adding, “This technology can accelerate the commercialization of anode-free lithium metal batteries in next-generation high-energy battery markets such as electric vehicles and energy storage systems (ESS).”
This research was conducted with Ph.D candidate Juhyun Lee, and postdoctoral Jinuk Kim, a postdoctoral researcher from the Department of Chemical and Biomolecular Engineering at KAIST, serving as co–first authors. The results were published on December 10, 2025, in Joule, one of the most prestigious journals in the field of energy.
※ Paper title: “A Strategic Tuning of Interfacial Li⁺ Solvation with Ultrathin Polymer Layers for Anode-Free Lithium Metal Batteries,” Authors: Juhyun Lee (KAIST, co–first author), Jinuk Kim (KAIST, co–first author), Jinwoo Lee (KAIST, corresponding author), Sung Gap Im (KAIST, corresponding author), among a total of 18 authors, DOI: 10.1016/j.joule.2025.102226
This research was conducted at the Frontier Research Laboratory, jointly established by KAIST and LG Energy Solution, and was supported by the National Research Foundation of Korea (NRF) Mid-Career Research Program, the Korea Forest Service (Korea Forestry Promotion Institute) Advanced Technology Development Program for High Value-Added Wood Resources, and the KAIST Jang Young Sil Fellowship Program.
2026.01.05 View 555 -
Hemostasis in 1 Second... Boosting Survival Rates for Soldiers
< (From top left) Professor Steve Park, Professor Sangyong Jon, (From bottom left) President Kwang-Hyung Lee, Ph.D canddiate Youngju Son, Ph.D candidate Kyusoon Park >
The leading cause of death due to injuries in war is excessive bleeding. A KAIST research team, in which an Army Major participated, has tackled this issue head-on. By developing a next-generation powder-type hemostatic agent that stops bleeding in one second just by spraying it, they have presented an innovative technology that will change the paradigm of combatant survivability.
KAIST announced on December 29th that a joint research team led by Professor Steve Park from the Department of Materials Science and Engineering and Professor Sangyong Jon from the Department of Biological Sciences has developed a powder-type hemostatic agent that forms a powerful hydrogel barrier within approximately one second when sprayed on a wound.
This technology reached a high level of perfection as a practical technology considering real combat environments, with an Army Major researcher directly participating in the study. By implementing characteristics that allow instant hardening even under extreme conditions such as combat and disaster sites due to high usability and storage stability, immediate emergency treatment is possible.
Until now, patch-type hemostatic agents widely used in medical fields have had limitations in application to deep and complex wounds due to their flat structure, and were sensitive to temperature and humidity, posing limits on storage and operation.
Accordingly, the research team developed a next-generation hemostatic agent in powder form that can be freely applied even to deep, large, and irregular wounds. They have secured versatility to respond to various types of wounds with a single powder.
< AGCL powder development strategy and fabrication schematin/ Gelation speed and blood absorption capacity of AGCL powder >
Existing powder hemostatic agents had limits in hemostatic capability as they functioned by physically absorbing blood to form a barrier. To solve this problem, the research team focused on the ionic reactions within the blood.
The ‘AGCL powder’ developed this time has a structure that combines biocompatible natural materials such as Alginate and Gellan Gum (which react with calcium for ultra-fast gelation and physical sealing) and Chitosan (which bonds with blood components to enhance chemical and biological hemostasis). It reacts with cations such as calcium in the blood to turn into a gel state in one second, instantly sealing the wound.
Furthermore, by forming a three-dimensional structure inside the powder, it can absorb blood amounting to more than 7 times its own weight (725%). Due to this, it quickly blocks blood flow even in high-pressure and excessive bleeding situations, and showed superior sealing performance compared to commercial hemostatic agents with a high adhesive strength of over '40kPa', a level of pressure that can withstand being pressed strongly by hand.
AGCL powder is composed entirely of naturally derived materials, showing a hemolysis rate of less than 3%, a cell viability rate of over 99%, and an antibacterial effect of 99.9%, making it safe even when in contact with blood. In animal experiments, excellent tissue regeneration effects such as rapid wound recovery and promotion of blood vessel and collagen regeneration were confirmed.
In surgical liver injury experiments, the amount of bleeding and hemostasis time were significantly reduced compared to commercial hemostatic agents, and liver function recovered to normal levels two weeks after surgery. No abnormal findings were observed in systemic toxicity evaluations.
In particular, this hemostatic agent maintains its performance for two years even in room temperature and high humidity environments, possessing the advantage of being ready for immediate use in harsh environments such as military operation sites or disaster areas.
Although this research is an advanced new material technology developed with national defense purposes in mind, it has great potential for application throughout emergency medicine, including disaster sites, developing countries, and medically underserved areas.
It is evaluated as a representative spin-off case* where national defense science and technology expanded to the private sector, as it is capable of everything from emergency treatment on the battlefield to internal surgical hemostasis.
*Spin-off case: Expanding or transferring national defense science and technology for use in the private sector. Examples include computers, GPS, microwave ovens, etc.
< Validation of efficacy in wounds through animal experiments / Validation of efficacy in a liver surgery model >
This study was recognized for its scientific innovation and national defense utility simultaneously, winning the 2025 KAIST Q-Day President's Award and the Minister of National Defense Award at the 2024 KAIST-KNDU National Defense Academic Conference.
Ph.D candidate Kyusoon Park (Army Major), who participated in the research, stated, “The core of modern warfare is minimizing the loss of human life,” and added, “I started the research with a sense of mission to save even one more soldier.” He continued, “I hope this technology will be used as a life-saving technology in both national defense and private medical fields.”
This research, in which KAIST PhD student Kyusoon Park and Ph.D candidate Youngju Son participated as lead authors and was guided by Professor Steve Park and Professor Sangyong Jon, was published online on October 28, 2025, in the international academic journal in the field of chemistry/materials engineering, Advanced Functional Materials (IF 19.0).
※ Paper Title: An Ionic Gelation Powder for Ultrafast Hemostasis and Accelerated Wound Healing, DOI: 10.1002/adfm.202523910
Meanwhile, this research was conducted with the support of the National Research Foundation of Korea (NRF)."
2025.12.29 View 6113 -
KAIST Researchers First in the World to Identify Security Threat Exploiting Google Gemini’s "Malicious Expert AI" Structure
<Photo 1. (From left) Ph.D. candidates Mingyoo Song and Jaehan Kim, Professor Sooel Son, (Top right) Professor Seungwon Shin, Lead Researcher Seung Ho Na>
Most major commercial Large Language Models (LLMs), such as Google’s Gemini, utilize a Mixture-of-Experts (MoE) structure. This architecture enhances efficiency by dynamically selecting and using multiple "small AI models (Expert AIs)" depending on input queries . However, KAIST research team has revealed for the first time in the world that this very structure can actually become a new security threat.
A joint research team led by Professor Seungwon Shin (School of Electrical Engineering) and Professor Sooel Son (School of Computing) announced on December 26th that they have identified an attack technique that can seriously compromise the safety of LLMs by exploiting the MoE structure. For this research, they received the Distinguished Paper Award at ACSAC 2025, one of the most prestigious international conferences in the field of information security.
ACSAC (Annual Computer Security Applications Conference) is among the most influential international academic conferences in security. This year, only two papers out of all submissions were selected as Distinguished Papers. It is highly unusual for a domestic Korean research team to achieve such a feat in the field of AI security.
In this study, the team systematically analyzed the fundamental security vulnerabilities of the MoE structure. In particular, they demonstrated that even if an attacker does not have direct access to the internal structure of a commercial LLM, the entire model can be induced to generate dangerous responses if just one maliciously manipulated "Expert Model" is distributed through open-source channels and integrated into the system.
<Figure 1. Conceptual diagram of the attack technology proposed by the research team.>
To put it simply: even if there is only one "malicious expert" mixed among normal AI experts, that specific expert may be repeatedly selected for processing harmful queries, causing the overall safety of the AI to collapse. A particularly dangerous factor highlighted was that this process causes almost no degradation in model performance, making the problem extremely difficult to detect in advance.
Experimental results showed that the attack technique proposed by the research team could increase the harmful response rate from 0% to up to 80%. They confirmed that the safety of the entire model significantly deteriorates even if only one out of many experts is "infected."
This research is highly significant as it presents the first new security threat that can occur in the rapidly expanding global open-source-based LLM development environment. Simultaneously, it suggests that verifying the "source and safety of individual expert models" is now essential—not just performance—during the AI model development process.
Professors Seungwon Shin and Sooel Son stated, "Through this study, we have empirically confirmed that the MoE structure, which is spreading rapidly for the sake of efficiency, can become a new security threat. This award is a meaningful achievement that recognizes the importance of AI security on an international level."
The study involved Ph.D. candidates Jaehan Kim and Mingyoo Song, Dr. Seung Ho Na (currently at Samsung Electronics), Professor Seungwon Shin, and Professor Sooel Son. The results were presented at ACSAC in Hawaii, USA, on December 12, 2025.
<Figure 2. Photo of the Distinguished Paper Award certificate>
Paper Title: MoEvil: Poisoning Experts to Compromise the Safety of Mixture-of-Experts LLMs
Paper File: https://jaehanwork.github.io/files/moevil.pdf
GitHub (Open Source): https://github.com/jaehanwork/MoEvil
This research was supported by the Korea Internet & Security Agency (KISA) and the Institute of Information & Communications Technology Planning & Evaluation (IITP) under the Ministry of Science and ICT.
2025.12.26 View 1275 -
Finding Solutions to Foreign Disinformation Through Youth Ideas
< Group Photo of the Awards Ceremony >
KAIST has announced that the awards ceremony for the ‘2025 Foreign Disinformation Response Idea Competition for University Students (Counter-Disinformation Challenge),’ organized by the Institute for Security Convergence in collaboration with the National Intelligence Service (NIS), is scheduled to be held on the afternoon of the 23rd at the KAIST Munji Campus.
This competition, held for the second time since its inaugural launch last year, was established to inform the public about the current state of the creation and spread of foreign disinformation and its resulting social and national harms, as well as to seek future response measures. It solicited practical ideas covering both technology and policy from university students and the general public.
Based on the awareness of the issues raised through last year’s competition, our university focused this year on strengthening the link between technology and policy and discovering ideas that can lead to actual research and development (R&D) and institutional improvements. Through this, the university plans to establish the foundation for a mid-to-long-term strategy for responding to foreign disinformation.
The competition was held from November 1st to December 5th in two categories: ▲ Technical ideas to prevent the spread of foreign disinformation, and ▲ Policy proposals and institutional improvement ideas to solve foreign disinformation issues. A total of 144 teams, comprising 259 university and graduate students (including those on leave) from across the country, participated.
Among them, 18 teams were selected as the final winners. This represents an improvement in both the scale of participation and the completeness of the proposals compared to last year, demonstrating the high level of interest among the youth in responding to foreign disinformation.
The awards consist of: ▲ Technical Idea category: 1 Grand Prize, 3 First Prizes, 5 Excellence Prizes; ▲ Policy Proposal and Institutional Improvement category: 1 Grand Prize, 3 First Prizes, 5 Excellence Prizes.
The Grand Prize (KAIST President's Award) in the ‘Technical Idea for Disinformation Response’ category will be awarded to Team ‘Lemming,’ composed of students Lee Jun, Kang Yun-ah, and Ma Seon-young from Jeju National University. Team Lemming proposed a technology that utilizes multi-persona AI agents to virtually simulate the creation, spread, and response processes of disinformation.
Additionally, the Grand Prize (KAIST President's Award) in the ‘Policy Proposal and Institutional Improvement for Disinformation Response’ category will be awarded to Team ‘Kim Anbo Girls,’ composed of student Kim Yeon-jung from Jungwon University and student Kim Hyun-jin from Baekseok Arts University.
Bae Joong-myeon, Director of the KAIST Institute for Security Convergence, stated, “Foreign disinformation is a future-type security threat where technology, policy, and society are complexly intertwined. We plan to link the students’ ideas to future R&D and policy reviews through collaboration with the National Intelligence Service and the Cyber Security Research Center of the KAIST Institute for Security Convergence.”
Meanwhile, the National Intelligence Service, which sponsored this competition, has been accepting reports of foreign disinformation 24 hours a day, 365 days a year through the ‘111 Reporting Center’ and its official website since September 2024, and is promoting the strengthening of an integrated response system through cooperation with related organizations.
< Event Poster >
2025.12.23 View 544 -
Breakthrough in Intractable Intestinal Disease Treatment Using Xenogeneic-Free Intestinal Stem Cells
< (From left) Professor Sung Gap Im (KAIST), Dr. Seonghyeon Park (KAIST), M.S candidate Sang Yu Sun (KAIST), Dr. Mi-Young Son (KRIBB), (Top right) Dr. Tae Geol Lee (KRISS), Dr. Jin Gyeong Son (KRISS) >
Intestinal Stem Cells (ISCs) derived from a patient's own cells have garnered significant attention as a new alternative for treating intractable intestinal diseases due to their low risk of rejection. However, clinical application has been limited by safety and regulatory issues arising from conventional culture methods that rely on animal-derived components (xenogeneic components). A KAIST research team has developed an advanced culture technology that stably grows ISCs without animal components while simultaneously enhancing their migration to damaged tissues and regenerative capabilities.
KAIST announced on December 23rd that a joint research team—led by Professor Sung Gap Im from the Department of Chemical and Biomolecular Engineering, Dr. Tae Geol Lee from the Nano-Bio Measurement Group at the Korea Research Institute of Standards and Science and Dr. Mi-Young Son from the Stem Cell Convergence Research Center at the Korea Research Institute of Bioscience and Biotechnology has developed a polymer-based culture platform that dramatically improves the migration and regeneration of ISCs in a xenogeneic-free environment.
To overcome obstacles in the clinical application of stem cell therapies—such as the risk of virus transmission to patients when using substances derived from mouse fibroblasts or Matrigel—the joint research team developed "PLUS" (Polymer-coated Ultra-stable Surface). This polymer-based culture surface technology functions effectively without any animal-derived materials.
< Figure 1. Precise control of polymer coating and surface modification via initiated Chemical Vapor Deposition (iCVD) process >
PLUS is a synthetic polymer surface coated via a vapor deposition method. By precisely controlling surface energy and chemical composition, it significantly enhances the adhesion and mass-culture efficiency of ISCs. Notably, it maintains identical culture performance even after being stored at room temperature for three years, securing industrial scalability and storage convenience for stem cell therapeutics.
Through proteomics analysis*, the research team identified that the expression of proteins related to cytoskeletal reorganization significantly increased in ISCs cultured on the PLUS environment.
Proteomics Analysis: A method used to simultaneously analyze the types and quantitative changes of all proteins present within a cell or tissue.
Specifically, the team confirmed that increased expression of cytoskeleton-binding and actin-binding proteins leads to a stable restructuring of the internal cellular architecture. This provides the power source for stem cells to move faster and more actively across the substrate.
< Figure 2. Elucidation of the mechanism for enhanced ISC migration through precision proteomics analysis >
Real-time observations using holotomography microscopy revealed that ISCs cultured on PLUS exhibited a migration speed approximately twice as fast as those on conventional surfaces. Furthermore, in a damaged tissue model, the cells demonstrated outstanding regenerative performance, repairing more than half of the damage within a single week. This proves that PLUS activates the cytoskeletal activity of stem cells, thereby boosting their practical tissue regeneration capabilities.
The newly developed PLUS culture platform is evaluated as a technology that will significantly enhance the safety, mass production, and clinical feasibility of ISCs derived from human pluripotent stem cells (hPSCs). By elucidating the mechanism that simultaneously strengthens the survival, migration, and regeneration of stem cells in a xenogeneic-free environment, the team has established a foundation to fundamentally resolve safety, regulatory, and productivity issues in stem cell therapy.
Professor Sung Gap Im of KAIST stated, "This research provides a synthetic culture platform that eliminates the dependence on xenogeneic components—which has hindered the clinical application of stem cell therapies—while maximizing the migration and regenerative capacity of stem cells. It will serve as a catalyst for a paradigm shift in the field of regenerative medicine."
Dr. Seonghyeon Park (KAIST), Sang Yu Sun (KAIST), and Dr. Jin Gyeong Son (KRISS) participated as first authors. The research findings were published online on November 26th in Advanced Materials, the leading academic journal in materials science.
Paper Title: Tailored Xenogeneic-Free Polymer Surface Promotes Dynamic Migration of Intestinal Stem Cells
DOI: 10.1002/adma.202513371
This research was conducted with support from the Ministry of Science and ICT, the Ministry of SMEs and Startups, the National Research Foundation of Korea, the National Council of Science and Technology Research, KRISS, KRIBB, and the National NanoFab Center.
2025.12.23 View 637