Kaist

KAIST, Developing National Positioning Infrastruct..

  <(From Left) Prof. Dong-Soo Han, Dr. Kyuho Son, Dr. Byeongcheol Moon, Dr. Sumin Ahn, Ph.D candidate Seungwoo Chae>   A Korean research team has developed a technology that enables precise indoor positioning using only a smartphone. Developed over eight years by KAIST researchers, this technology is expected to help secure critical time in missing-person searches and is being recognized as a “location sovereignty” solution that could reshape the current location service ecosystem dominated by global big tech companies such as Google and Apple. KAIST (President Kwang Hyung Lee) announced on the 2nd pf April that a research team led by Professor Dongsoo Han of the School of Computing has developed a core technology that can build a nationwide high-precision positioning infrastructure in a short time and at low cost by combining smartphone Wi-Fi signals with real-world address data. This achievement is the result of eight years of research, during which the team filed around ten patents to enhance the technology’s completeness. The key feature of this technology is its use of Wi-Fi signals collected by smartphones in everyday life. It can provide precise location information anywhere in the country without requiring large-scale equipment or additional infrastructure. It also maintains high accuracy in environments where GPS is weak, such as indoors, underground, or in dense high-rise areas. In particular, this research is seen as a challenge to the location service ecosystem currently led by global platform companies. Today, most location data worldwide is accumulated and managed by a small number of big tech firms, and Korea also relies heavily on these platforms. Most importantly, this research establishes a foundation for independently building and managing location data generated domestically. Amid ongoing debates over exporting high-resolution national maps (1:5,000 scale spatial data detailing buildings and roads), the importance of data sovereignty is growing. This technology is drawing attention as an alternative that could reduce dependence on global big tech and realize “location sovereignty.” The research team proposed a method that automatically combines Wi-Fi signals collected during smartphone app usage with the actual address of the location. This allows the construction of a unique “signal pattern map” (signal fingerprint) for each place, with accuracy improving as more data accumulates. In a real-world demonstration in Daejeon, using a gas meter reading app, an average of about 30 Wi-Fi signals were detected per household in apartment complexes. This confirmed that city-scale location data can be rapidly built using this approach. <Status of Radio Map Construction in Daejeon Using a Gas Meter Reader App> <Address-Based Automation of Wireless Signal Collection and AI-Based Location Labeling Techniques for Collected Wireless Signals> This technology is expected to significantly reduce location errors—previously up to hundreds of meters—in emergency situations such as missing-person searches, helping secure critical response time. It can also be applied to “location-based authentication,” allowing payments only at specific locations, thereby helping prevent financial crimes such as identity theft or unauthorized remote transactions. Furthermore, precise location data is a key infrastructure for future AI industries, including autonomous driving, robotics, and logistics. This achievement is expected to enhance competitiveness across these sectors. <Research Use Image (AI-Generated Image)> Professor Dongsoo Han stated, “Positioning infrastructure is not just a convenience technology but a core asset directly linked to national data sovereignty,” adding, “It is time for the government, telecom companies, and platform providers to collaborate in building an independent national positioning infrastructure.” This research was supported by the Ministry of Science and ICT, the National Research Foundation of Korea, the National Fire Agency, and the Korea Evaluation Institute of Industrial Technology (KEIT) (Grant No. RS-2025-02313957).  

Excellence Award at the 4th Wonik Next-Generation ..

  < 4th Wonik Next-Generation Engineering Award hosted by the National Academy of Engineering of Korea (NAEK)>       At the 4th Wonik Next-Generation Engineering Award hosted by the National Academy of Engineering of Korea (NAEK), KAIST Ph.D candidate Yehhyun Jo from the Department of Electrical Engineering(Advisor: Professor Hyunjoo J. Lee) and Ph.D candidate Seokjoo Cho from the Department of Mechanical Engineering(Advisor: Prof. Inkyu Park) received Excellence Awards.   Yehhyun Jo was selected in recognition of the development of a system that enables the precise modulation and observation of brain functions by integrating ultrasound neuromodulation technology, MEMS, and biosignal measurement technology. As a leading researcher in ultrasound brain stimulation in Korea, Yehhyun has contributed to the advancement of next-generation neuroengineering research by publishing six SCI(E)-indexed first-author papers. In acceptance speech, Yehhyun Jo remakred, “It is a great honor to receive the Excellence Award at the Wonik Next-Generation Engineering Award hosted by the National Academy of Engineering of Korea. I believe this award represents not only my personal achievements, but also the collective efforts of my advisor, fellow researchers, and my parents and brother, who have supported my research behind the scenes. Going forward, I will continue to develop and validate technologies grounded firmly in fundamental principles so that engineering innovation can reach real clinical and industrial settings, and I will strive to become a great researcher who contributes to society through responsible research.” <(From Left) Ph.D candidate Yehhyun Jo, Ph.D candidate Seokjoo Cho>   Seokjoo Cho was selected for developing a wireless multi-modal sensing system based on nano- and micro-fabrication processes for the management of chronic wounds and metabolic diseases. Through this related work, Seokjoo has published 25 SCI(E)-indexed papers and is leading technological innovation in next-generation healthcare sensor platforms. He accepted the award, saying, “I am sincerely grateful to receive the great honor of the Wonik Next-Generation Engineering Award. Winning an award that I have long dreamed of as a researcher during my graduate studies brings me both deep fulfillment and a strong sense of responsibility. Taking this award as an opportunity, I will continue striving to grow as a researcher who does not lose sight of my original motivation and who can create meaningful value for society.”   The Wonik Next-Generation Engineering Award is presented to undergraduate and graduate students in engineering-related fields in Korea to recognize creative and ambitious future engineers in the materials, components, and equipment sectors and support their growth into engineers who contribute to solving social problems.   The award ceremony was held on the afternoon of March 10 at the Grand Walkerhill Seoul Hotel in Gwangjin-gu, Seoul.        

AI Blueprints Stolen with a Single Antenna... Coun..

  < Professor Jun Han >   From smartphone facial recognition to autonomous vehicles, Artificial Intelligence (AI) has long been protected as a "black box." However, a joint research team from KAIST and international institutions has uncovered a new security threat capable of "peeking" at AI blueprints from behind walls. The team also presented corresponding defense technologies. This discovery is expected to be utilized in strengthening AI security across various sectors, including autonomous driving, healthcare, and finance. On the 31st, Professor Jun Han’s research team from the KAIST School of Computing announced that they, in collaboration with the National University of Singapore (NUS) and Zhejiang University, developed "ModelSpy"—an attack system capable of hijacking AI model structures from a distance using only a small antenna. This technology works much like a bugging device, capturing and analyzing minute signals emitted while an AI is operational to reconstruct its internal structure. The research team focused on the electromagnetic (EM) waves generated by Graphics Processing Units (GPUs), which handle AI computations. When an AI performs complex calculations, the GPU emits subtle electromagnetic signals. By analyzing the patterns of these signals, the team successfully restored the layer configurations and detailed parameter settings of the AI model. Experimental results showed that the structure of AI models could be identified with high accuracy from up to 6 meters away or through walls, across five types of the latest GPUs. Notably, the team estimated the core structure—the layers of the deep learning model—with an accuracy of up to 97.6％. < AI model structures can be stolen through walls using an antenna hidden in a bag > This technology is considered a significant security threat because, unlike traditional hacking, it does not require direct server infiltration or malware installation. An attack can be carried out using only a portable antenna small enough to fit in a bag. Recognizing that this technology could lead to the leakage of a company's core AI assets, the research team also proposed defensive measures, such as electromagnetic interference and computational obfuscation. This is being hailed as a responsible security study that goes beyond demonstrating an attack to suggesting realistic protection methods. "This research demonstrates that AI systems can be exposed to new types of attacks even in physical environments," said Professor Jun Han. "To protect critical AI infrastructure, such as autonomous driving and national facilities, it is essential to establish 'cyber-physical security' systems that encompass both hardware and software." < Research Image (AI-generated) > Professor Jun Han of the KAIST School of Computing participated as a co-corresponding author. The study was presented at the NDSS (Network and Distributed System Security Symposium) 2026, a top-tier academic conference in computer security, where it received the Distinguished Paper Award in recognition of its innovation. Paper Title: Peering Inside the Black-Box: Long-Range and Scalable Model Architecture Snooping via GPU Electromagnetic Side-Chan Paper Link: https://www.ndss-symposium.org/ndss-paper/peering-inside-the-black-box-long-range-and-scalable-model-architecture-snooping-via-gpu-electromagnetic-side-channel/        

KAIST Enables Ultra-High-Resolution AR·VR Without ..

  <(From Left) Professor Young Min Song, Ph.D candidate Hyo Eun Jeong, (Upper Left) Professor Hyeon-Ho Jeong, Dr. Joo Hwan Ko>     A new display technology has emerged that significantly increases resolution while consuming almost no power. A Korean research team has developed a “monopixel” structure in which a single pixel can independently change colors while consuming minimal energy to maintain them. This breakthrough opens the possibility of creating sharper AR/VR displays without heavy battery demands. KAIST (President Kwang Hyung Lee) announced on the 29th of March that a research team led by Professor Young Min Song of the School of Electrical Engineering, in collaboration with Professor Hyeon-Ho Jeong’s team at Gwangju Institute of Science and Technology (GIST, President Ki-Cheol Lim), has developed a new low-power monopixel technology called a “reconfigurable Gires–Tournois resonator (r-GT).” This system uses electrochromic materials—substances that change color when electricity is applied—to produce colors with very low power consumption. Displays have been making pixels increasingly smaller to achieve higher resolution. However, as pixels shrink, power consumption rises and brightness decreases. This is especially challenging for AR/VR devices, which must achieve both extremely small pixels and low power consumption due to their proximity to the human eye. The r-GT pixel developed by the research team changes color when voltage is applied, and once changed, the color is maintained for a certain period even after the power is turned off. In other words, power is only required when changing colors, while maintaining color requires almost no energy. The core of this technology lies in two elements. First is a conductive polymer, polyaniline (PANI), whose properties change when voltage is applied. This material responds even at voltages below 1 volt (V), altering its refractive index and thereby changing color. The refractive index refers to how much light bends when passing through a material, and changes in this value lead to changes in perceived color. Second, the system incorporates a resonator structure that reflects light multiple times to amplify specific colors. This structure enhances even small changes, enabling vivid color expression with minimal power. As a result, the system achieved a wide color variation exceeding 220° using ultra-low power (90 μW cm⁻²). In simple terms, it can express more than half of the full color wheel (360°) using only about 0.00009 watts per square centimeter. Another key feature is the “monopixel” structure. Unlike conventional displays that divide a single pixel into red (R), green (G), and blue (B) subpixels, the monopixel approach allows one pixel to independently produce various colors. This enables more pixels within the same area, resulting in higher resolution and reduced light loss, leading to clearer images. Additionally, PANI retains its color state even after the applied voltage is removed. This confirms the feasibility of a “memory-in-pixel” display, where energy is used only when changing colors, not when maintaining them. <Reflective display AI image> The research team demonstrated that this technology can achieve a wide color range (220.6°) and reduce pixel size to as small as 1.5 micrometers (μm), corresponding to an ultra-high resolution of up to approximately 16,900 PPI—beyond the level where individual pixels can be distinguished by the human eye. Moreover, even with a single-pixel structure, the system can represent about 48.1％ of the standard sRGB color gamut, and up to 69.9％ with varied material combinations, enabling richer color expression. The team fabricated a 5×5 monopixel array to verify performance. The energy required to change colors was extremely low (2.31 mJ), demonstrating up to 5.8 times lower power consumption compared to conventional LEDs. As a reflective display, it also becomes more visible under brighter ambient lighting, since it uses external light rather than emitting its own. <Structure and Representative Results of an Electrically Tunable Single Reflective Resonant Device Using Conductive Polymers> This study demonstrates that combining electrochemical materials with optical resonator structures enables full-color implementation at ultra-low power. It is expected to be applied in various fields requiring energy efficiency, including ultra-high-resolution near-eye displays for AR/VR, wearable devices, outdoor displays, and electronic paper. It also suggests the potential for sustainable and energy-efficient display technologies by minimizing power consumption during color retention. Professor Young Min Song stated, “This technology allows a wide range of color changes using very little electricity,” adding, “When combined with future display driving methods, it could enable not only clearer and more energy-efficient ultra-high-resolution displays but also a variety of optical applications.” This research was conducted with Hyo Eun Jeong, an integrated M.S./Ph.D. student at KAIST, as co-first author, and Professor Young Min Song as the corresponding author. The results were published online on February 28 in Light: Science & Applications, a leading international journal in optics. ※ Paper title: “Sub-1-volt, reconfigurable Gires-Tournois resonators for full-coloured monopixel array,” DOI: https://www.nature.com/articles/s41377-026-02228-2 This research was supported by multiple programs funded by the Ministry of Science and ICT, the National Research Foundation of Korea (NRF), the InnoCORE-GIST program, nanomaterials and technology development initiatives, future medical innovation programs, international collaboration hubs, and the Ministry of Trade, Industry and Energy (MOTIE).      

KAIST Researchers Unveil Technical Principles Behi..

  < (From left) Professor Hyun Jung Chung , Ph.D candidate Ju Yeon Chung, Ph.D candidate Sujin Cha, Professor Sang Ouk Kim >   Hygiene in everyday items that touch the body—such as clothing, masks, and toothbrushes—is critically important. The underlying principle of how graphene selectively eliminates only bacteria has now been revealed. A KAIST research team has presented the potential for a next-generation antibacterial material that is safe for the human body and capable of replacing antibiotics. KAIST announced on March 25th that a joint research team, led by Professor Sang Ouk Kim from the Department of Materials Science and Engineering and Professor Hyun Jung Chung from the Department of Biological Sciences, has identified the mechanism by which Graphene Oxide (GO) exhibits powerful antibacterial effects against bacteria while remaining harmless to human cells. Graphene oxide is a nanomaterial consisting of an atomic level carbon layer (graphene) with oxygen attached; it is characterized by its ability to mix well with water and implement various functions. This study is highly significant as it provides molecular-level proof of graphene's antibacterial action, which had not been clearly understood until now. The research team confirmed that graphene oxide performs "selective antibacterial action" by attaching to and destroying only the membranes of bacteria, much like a magnet attaches only to specific metals, while leaving human cells untouched. This occurs because the oxygen functional groups on the surface of graphene oxide selectively bind with a specific component (POPG) found only in bacterial cell membranes. Simply put, it recognizes a "target" present only in bacterial membranes to attach and destroy the structure. In this context, phospholipids are fatty components that make up the membrane surrounding a cell, and POPG is a component primarily present in bacteria. < Schematic diagram of the selective interaction between graphene oxide and cell membranes > < Identification of selective interaction mechanisms at the molecular level through microscopic and chemical analysis of artificial lipid vesicles mimicking cell membranes > Nanofibers applying this principle effectively inhibited the growth of various pathogenic bacteria, including superbugs resistant to antibiotics. Animal experiments also confirmed its effectiveness in promoting wound healing without inducing inflammation. < Verification of antibacterial and wound healing enhancement effects in a porcine infected wound model > Furthermore, fibers using this material maintained their antibacterial functions even after multiple washes, showing potential for use in various industrial fields such as apparel and medical textiles. This technology is already being applied to consumer products. The graphene antibacterial toothbrush, released through the original patents of the faculty-led startup 'Materials Creation Co., Ltd.,' has sold over 10 million units, proving its commercial viability. Additionally, GrapheneTex—textile materiala incorporating this technology—was used in the uniforms of the Taekwondo demonstration team at the 2024 Paris Olympics and is expected to play an active role in functional sportswear at upcoming international sporting events like the 2026 Asian Games. < Commercially available graphene toothbrush > < Graphene material image (AI-generated image) > Professor Sang Ouk Kim explained, "This study is an example of scientifically uncovering why graphene can selectively kill bacteria while remaining safe for the human body." He emphasized, "By utilizing this principle, we can expand beyond safe clothing without harsh chemicals to an infinite range of applications, including wearable devices and medical textile systems." Sujin Cha (PhD program, Department of Materials Science and Engineering) and Ju Yeon Chung (Integrated MS/PhD program, Department of Biological Sciences) participated as first authors. Professor Hyun Jung Chung participated as a co-corresponding author. The research was published on March 2nd in the prestigious materials science journal, Advanced Functional Materials. ※ Paper Title: Biocompatible but Antibacterial Mechanism of Graphene Oxide for Sustainable Antibiotics, DOI: 10.1002/adfm.202313583 Additionally, Nanowerk (http://www.nanowerk.com/), a global portal for nanotechnology, featured these findings as a 'Spotlight' titled "Graphene oxide destroys bacteria without harming human tissue." This research was conducted with support from the 'Nano/Material Technology Development (R&D)' program, the 'Individual Basic Research' program, and the 'Mid-Career Researcher Support Program' funded by the Ministry of Science and ICT.  

KAIST solves solar cell dilemma… achieving over 25..

  <(Upper Left) Dr. Chansu Moon,(From Left) Dr. Namjoong Jeon, Ph.D candidate Jaehee Lee, M.S candidate Hajin Na, Professor  Jangwon Seo>     A KAIST research team has solved the “solar cell dilemma,” in which increasing efficiency shortens lifespan, while extending lifespan lowers efficiency. The team developed a technology to precisely control the internal structure of a surface passivation layer in perovskite solar cells, successfully achieving both high efficiency exceeding 25％ and long-term stability at the same time. KAIST (President Kwang Hyung Lee) announced on the 24th that a research team led by Distinguished Professor Jangwon Seo of the Department of Chemical and Biomolecular Engineering, in joint research with the Korea Research Institute of Chemical Technology (KRICT) (President Young-guk Lee), developed a 2D passivation layer design technology that simultaneously improves the efficiency and long-term stability of perovskite solar cells. <Research Concept Diagram (AI-Generated Image)> As the need to respond to the climate crisis and transition energy systems grows, improving the efficiency of solar power generation and securing long-term reliability have emerged as important challenges. In particular, perovskite solar cells, which are attracting attention as next-generation high-efficiency solar cells, have recently achieved rapid efficiency improvements. However, they have been pointed out as having commercialization barriers due to performance degradation under high temperature, high humidity, or prolonged light exposure. Previously, a “3D/2D structure” strategy—adding a 2D layer on top of a 3D perovskite layer—has been used. This method helps reduce surface defects and improve stability. However, if the structure of the 2D layer is not sufficiently robust, it has limitations in that the structure may deform over time or performance may gradually decline. To address this, the research team introduced a structurally more stable Dion–Jacobson (DJ) type 2D perovskite passivation layer and proposed a design strategy that precisely controls the “n value,” which refers to the number of stacked perovskite layers within the passivation layer. The DJ structure enhances structural stability by firmly connecting perovskite layers with organic molecules on both sides. In simple terms, it is similar to binding bricks together with a stronger adhesive so that the structure does not easily collapse. The research team controlled the stacking structure (n value) of perovskite layers inside the 2D passivation layer in a desired manner by adjusting heat treatment conditions, analogous to how controlling temperature and time during the curing of adhesive after stacking bricks results in a more solid and orderly structure. As a result, charge transport became more efficient, improving solar cell efficiency, and the robust characteristics of the DJ structure also enhanced long-term stability. In addition, the team experimentally revealed that during the heat treatment process, the internal structure of the 2D passivation layer changes as the structure is rearranged at the interface where different materials meet. They also presented the principles for controlling the passivation layer structure and reproducible process conditions. The perovskite solar cell applying this design strategy recorded a high power conversion efficiency of 25.56％ (certified efficiency of 25.59％). It also maintained a high level of performance under conditions of 85°C and 85％ relative humidity (85％ RH) as well as continuous light exposure, confirming long-term stability. The research team further applied this technology to the fabrication of large-area modules and verified excellent performance. <Schematic Diagram of Structure Formation Strategy (left) and Structural Evolution (right)> Distinguished Professor Jangwon Seo stated, “This study demonstrates that the longstanding challenge—where increasing efficiency reduces lifespan and increasing lifespan lowers efficiency—can be solved simultaneously through structural design of the surface passivation layer.” He added, “This technology operates relatively stably even under changes in process conditions, making it helpful for large-area manufacturing processes for commercialization.” This study, co-first-authored by Jaehee Lee (integrated M.S./Ph.D. student at KAIST) and Dr. Chansu Moon (KRICT), was published in the international energy journal Joule (IF 35.4) on February 24, 2026. ※ Paper title: “Tailored n value engineering of Dion-Jacobson 2D layers enables efficient and stable perovskite solar cells,” DOI: 10.1016/j.joule.2025.102301 ※ Author information: Jaehee Lee (integrated M.S./Ph.D. program, KAIST, co-first author), Chansu Moon (former KRICT, co-first author), Dr. Namjoong Jeon (KRICT, corresponding author), Distinguished Professor Jangwon Seo (KAIST, corresponding author) This research was supported by the National Research Foundation of Korea (NRF) (Nano and Materials Technology Development Program [Materials Hub], Basic Research Program [Mid-career], Engineering Research Center [ERC]) and the core program of KRICT. Some experiments were supported by beamlines at the Pohang Accelerator Laboratory (PAL).  

World’s First SoulMate AI Semiconductor： A Persona..

  < (From left) KAIST Professor Hoi-Jun Yoo and PhD candidate Seongyon Hong >     While Large Language Models (LLMs) like ChatGPT are adept at answering countless questions, they often remain unaware of a user's minor habits or previous conversational contexts. This is why AI, despite being deeply integrated into our daily lives, can still feel like a "stranger." Overcoming these limitations, researchers at KAIST have developed the world’s first AI semiconductor, dubbed "SoulMate," which learns and adapts to a user’s speech style, preferences, and emotions in real-time—becoming a true "digital soulmate." KAIST announced on March 17th that a research team led by Professor Hoi-Jun Yoo from the Graduate School of AI Semiconductors has developed SoulMate, a personalized LLM accelerator that evolves according to the specific characteristics of the user.This technology is being hailed as a core semiconductor breakthrough that will accelerate the era of "Hyper-Personalized AI"—moving beyond "AI for everyone" to an AI that learns and responds to an individual's unique conversational style and preferences. The core of SoulMate lies in On-Device AI technology, which processes data directly on the device without going through external servers (the cloud). The team directly implemented Retrieval-Augmented Generation (RAG), which generates customized answers based on remembered conversations, and Low-Rank Adaptation (LoRA), which immediately reflects and learns from user feedback, within the semiconductor itself. < SoulMate AI Semiconductor Chip > Through this, SoulMate has realized a real-time personalized AI system that responds to the user at a staggering speed of 0.2 seconds (216.4 ms) while simultaneously performing learning tasks. < SoulMate Application Demo > Furthermore, the team applied a Mixed-Rank architecture that optimizes processing methods based on the importance of information, drastically reducing power consumption. The semiconductor operates at an ultra-low power of just 9.8 milliwatts (mW)—approximately 1/500th of a typical smartphone processor's power consumption—allowing it to handle complex learning and inference simultaneously on mobile devices without battery concerns. In particular, SoulMate features a "Security-Complete AI" structure where all personal data is processed internally within the device rather than being transmitted to external servers, fundamentally blocking any risk of personal information leaks. The research team expects this technology to pair with next-generation platforms such as smartphones, wearables, and personal AI devices to open a true era of personalized AI services. < SoulMate Demo Screen > "This research mimics the process of people building friendships, providing the technical foundation for AI to evolve into a true companion for the user," said Professor Hoi-Jun Yoo. "Future AI will move beyond being a mere tool to become a 'Best Friend' that understands me best anytime, anywhere, while perfectly protecting personal privacy." The study, with PhD student Seongyon Hong as the first author, was selected as a "Highlight Paper" at the International Solid-State Circuits Conference (ISSCC) held in San Francisco this past February, garnering significant attention from the global academic community. Paper Title: SoulMate: A 9.8mW Mobile Intelligence System-on-Chip with Mixed-Rank Architecture for On-Device LLM Personalization Authors: Seongyon Hong, Jiwon Choi, Jeonggyu So, Nayeong Lee, Wooyoung Jo, Zhamaliddin Kalzhan Link: https://ieeexplore.ieee.org/document/11409048 At the conference, the research team successfully demonstrated how the AI's response style changes in real-time according to user reactions using the actual semiconductor chip, proving the excellence of Korean AI semiconductor technology. The SoulMate AI semiconductor is planned for commercialization around 2027 through the faculty-led startup "OnNeuro AI." < SoulMate Demonstration Photo > This research was conducted with support from the Information and Communication Broadcast Innovation Talent Cultivation Program of the Ministry of Science and ICT and the Institute of Information & Communications Technology Planning & Evaluation (IITP).

Turning a Toxic Gas into a Therapeutic Tool Using ..

  <(From Left) Professor Jimin Park, Dr. Jaewoong Lee, M.S candidate Lian Lim, Ph.D candidate Changho Lee>     KAIST Research Team Develops a 'Bioelectronic Platform' for Precision Hydrogen Sulfide Delivery, Opening New Doors for Digital Healthcare and Precision Medicine A toxic gas known for its "rotten egg smell" has been transformed into a therapeutic tool. A research team at KAIST has developed a technology to precisely control hydrogen sulfide (H2S) using electrical signals, bringing us one step closer to precision medicine that targets only the desired areas while minimizing side effects. KAIST announced on March 23 that a research team led by Professor Jimin Park from the Department of Chemical and Biomolecular Engineering has developed a "bioelectronic H2S delivery platform." This platform can precisely regulate the generation and delivery of H2S at specific times and locations. < Schematic Diagram of a Hydrogen Sulfide–Generating Bioelectronic Platform (AI-Generated Image) > While H2S has long been recognized as a hazardous substance due to its odor and toxicity, it has recently gained attention as a "biological signaling molecule" that maintains cellular health and regulates protein functions. In particular, H2S acts as a "chemical switch" that can modulate protein functions by subtly altering their conformations. However, its use in clinical therapy has been limited because it is difficult to control its concentration and deliver it precisely to specific sites. The research team solved these issues by implementing a technology that controls H2S delivery precisely like an electrical switch. Inspired by the metabolic cycles of bacteria in nature, the team designed a system that generates H2S by applying electricity to thiosulfate ions (S2O32-), a precursor harmless to the human body. This method offers higher safety and precision compared to conventional chemical administration methods. < Hydrogen Sulfide Regulation Capability Depending on Electrode Materials and Input Parameters > Furthermore, through a comparative analysis of various metal electrodes, the team identified the "silver (Ag) electrode" as the most efficient material for H2S electrosynthesis. The Ag electrode selectively generates H2S with high electron transfer efficiency, allowing precise control over its production. Using this platform, both the amount and release kinetics of H2S can be finely tuned by adjusting the voltage and electrolysis time, enabling delivery at the optimal time based on the patient’s condition or the treatment site. When applied to human-derived cells (HEK293T), the research team successfully regulated ion channels (TRPA1), which act as an internal cellular "switch" for sensing pain and irritation. Notably, when applied to cells under oxidative stress (such as those with increased reactive oxygen species), the delivered H2S restored cellular redox balance and demonstrated protective effects. Minimal cytotoxicity was observed, confirming its safety for potential human applications. < Spatiotemporal Regulation of TRPA1 Activation by a Hydrogen Sulfide–Delivering Bioelectronic Platform > < Spatiotemporal Recovery of Oxidative Stress Using a Hydrogen Sulfide–Delivering Bioelectronic Platform > Professor Jimin Park explained, "This study is significant in that it transforms H2S, once regarded solely as a toxic substance, into a new tool for regulating biological systems through precise electrical control." He added, "This technology holds great potential for expansion into precision medical devices for treating neurological and cardiovascular diseases, as well as digital healthcare for real-time health management." This research involved Lian Lim, Changho Lee, and Jaewoong Lee as co-first authors. The study also included contributions from Myeongeun Lee, Yongha Kim, Tae Kyoung Lee, Gwangbin Lee, Jinsoo Kim, and Sang Yeon Oh, with Professor Jihan Kim as a co-author and Professor Jimin Park as the corresponding author. The findings were published on March 19 in the internationally renowned academic journal Science Advances. Paper Title: Bioelectronic Synthesis of Hydrogen Sulfide Enables Spatiotemporal Regulation of Protein Modification and Cellular Redox DOI: https://doi.org/10.1126/sciadv.aeb3401 This research was supported by the National Research Foundation of Korea (NRF) through the Young Researcher Program and the Global Matching Program. < Research Illustration (AI-Generated Image) >  

KAIST Develops Motor-less Robotic Hand Actuation T..

  < (From left) KAIST Ph.D. students Sangyoon Bae and Professor Seong Su Kim, Ph.D. student Dajeong Kang, and Dr. Wonvin Kim >     While space structures and robotic arms require lightweight actuation devices capable of repetitive movement, conventional motor-based systems face limitations due to their heavy weight and complex structures. A KAIST research team has developed a smart material-based actuation technology that operates rapidly in less than a second without a motor, suggesting new possibilities for next-generation robotics and space deployable structures.  KAIST announced on the 22nd that a research team led by Professor Seong Su Kim from the Department of Mechanical Engineering has developed a "two-way shape memory material-based hybrid smart actuator" capable of "reversible self-shape change." This technology allows the material to change its shape in response to external stimuli, such as heat, and return to its original state without the need for additional complex mechanical devices. The research team designed a hybrid composite actuator that combines Shape Memory Alloys (SMA) and Shape Memory Polymers (SMP) to leverage the advantages of both materials. SMAs are metallic materials that return to their original shape when heated, while SMPs are polymer materials that change shape in response to heat or other external stimuli. Conventional shape memory materials had limitations; they either could not return to their original state once deformed (one-way) or had extremely slow recovery speeds. Furthermore, because metal alloys and polymer materials have different levels of stiffness, they often failed to restore their shape accurately during repetitive use. To solve these issues, the research team improved both the material and its structure. First, they adjusted the chemical composition of the SMP and reinforced it with carbon fibers to make the material more rigid. Additionally, they applied a "tape spring" structure—similar to a retractable measuring tape—to the actuator. This structure creates a "snap-through" phenomenon, where energy is stored during deformation and released instantaneously, significantly increasing both the speed and accuracy of the movement. As a result, the developed actuator achieved full two-way actuation, bending when heated and flattening again as the temperature drops. The technology also demonstrated a significantly increased range of deformation and a nearly 100％ recovery rate to the initial shape. The recovery speed was also greatly improved, confirming that the actuator can operate repeatedly without the need for complex control systems. < Development process of the SMA-SMP hybrid two-way actuator > The shape memory actuator developed in this study is highly significant as it simultaneously achieves two-way deformation, sub-second actuation speed, and high deployment accuracy. This achievement is evaluated as a major step forward in the practical application of shape memory material-based actuation technology. Professor Seong Su Kim stated, "This research overcomes the physical limitations of materials through original structural design, elevating the performance of shape memory actuators to the next level. We expect this technology to be applied in various fields, such as robotic grippers requiring repetitive motions or deployable structures for space applications." Dajeong Kang, a Ph.D. student, participated as the lead author of this study. The paper was published online on January 19, 2026, in Advanced Functional Materials, an international journal published by Wiley. In recognition of its excellence, the study was featured as the Front Cover of the March 2026 issue of Advanced Functional Materials. Paper Title: Two-Way Shape Memory Alloy and Polymer Composite Hybrid Smart Actuator With High Speed, Accuracy, and Reversible Deformation DOI: https://doi.org/10.1002/adfm.202528863 Author Information: Dajeong Kang (KAIST, First Author), Seong Yeon Park (KAIST, Co-author), Yitro Samuel Aditya (KAIST, Co-author), Ha Eun Lee (KAIST, Co-author), Wonvin Kim (KAIST, Co-author), Sangyoon Bae (KAIST, Co-author), and Seong Su Kim (KAIST, Corresponding Author) < Image of the Front Cover of Advanced Functional Materials > This research was conducted with the support of the Nano and Materials Technology Development Program (Project No. RS-2024-00450477) and the National Semiconductor Research Laboratory Core Technology Development Program (Project No. RS-2023-00260461) funded by the Ministry of Science and ICT and the National Research Foundation of Korea.      

KAIST Expands Storage Capacity with Smart Gate Sem..

  <(From Left) Ph. D candidate Dae Hyun Kang, Professor Byung Jin Cho>   From smartphones to large-scale AI servers, most digital information in modern society is stored in NAND flash memory＊. KAIST researchers have developed an innovative technology that can overcome the limitations of next-generation semiconductors, where more data must be stored in smaller spaces. This advancement is expected to serve as a key enabling technology for realizing ultra-high-capacity memory. ＊NAND flash memory: a non-volatile semiconductor memory used in storage devices such as smartphones and SSDs, where data such as photos, videos, and apps are retained even when power is turned off. KAIST (President Kwang Hyung Lee) announced on the 20th of March that a research team led by Professor Byung Jin Cho of the School of Electrical Engineering has overcome the scaling limitations of 3D V-NAND memory＊ by implementing a “smart gate” structure that selectively controls electron movement depending on conditions, using a new material applied to an ultra-thin semiconductor layer thinner than a human hair. ＊3D V-NAND: a memory technology that stacks memory cells vertically, unlike conventional planar (2D) arrangements, enabling higher data storage density. This research is particularly significant in that it addresses the longstanding issues of speed degradation and reliability during data write and erase operations by utilizing a novel material called boron oxynitride (BON). In semiconductor memory, the tunneling layer—a thin insulating layer that acts as a pathway for electrons to move in and out of the memory cell—has historically faced a trade-off between performance and reliability. With conventional materials, it has been difficult to achieve both simultaneously. For example, the widely used silicon oxynitride (SiON) increases data leakage when the tunneling path is widened to improve erase speed, while narrowing the path to prevent leakage significantly slows down data erasure. This trade-off has been a major obstacle to implementing next-generation penta-level cell (PLC) technology. PLC technology stores 5 bits of data per memory cell by distinguishing 32 different voltage states, allowing much higher data density within the same physical size. To overcome this limitation, the research team introduced BON, a completely new material beyond conventional silicon-based systems, into the tunneling layer. This material exhibits a unique physical property in which the energy barrier height differs depending on the type of charge carrier. Leveraging this property, the team designed an asymmetric energy barrier structure that allows holes (positive charge carriers)—needed for data erase—to pass through easily, while blocking electrons, which represent stored data, from leaking out. An asymmetric energy barrier refers to a structure in which the energy required for charge carriers to move varies depending on the type of charge. This enables efficient charge transport during erase operations while effectively preventing data loss. The concept is analogous to a “smart gate” that opens easily for entry but firmly blocks exit, implemented at the semiconductor level. Experimental results showed that devices using the BON tunneling layer achieved up to a 23-fold improvement in erase speed compared to conventional technologies and demonstrated excellent durability with minimal performance degradation even after tens of thousands of operation cycles. Notably, even under the highly demanding PLC operation—where 32 distinct voltage levels must be precisely controlled—the researchers achieved more than threefold improvement in controlling data distribution across devices. < Schematic diagram of the asymmetric energy barrier structure and operating principle of the BON tunneling layer > This achievement is considered by both academia and industry to be beyond a purely experimental result, reaching a level immediately applicable to real semiconductor manufacturing processes. Professor Byung Jin Cho stated, “This research presents a novel technology that can be directly applied to the production of next-generation ultra-high-capacity memory,” adding, “It will significantly contribute to maintaining Korea’s technological leadership in the semiconductor industry.” This study was implemented by Dae Hyun Kang, an integrated master’s–PhD student in Electrical Engineering, as the first author. The research was presented at the IEEE International Electron Devices Meeting (IEDM) on December 9, one of the most prestigious conferences in the semiconductor field, attracting global attention. The work also received the Grand Prize (first place overall in the university category) at the 32nd Samsung Human Tech Paper Awards, marking a notable achievement as a traditional semiconductor device study in a competition typically dominated by AI-related research. ※ Paper title: “Bandgap-Engineered Boron Oxynitride Tunneling Layer for Reliable PLC Operation of 3D V-NAND Flash Memory Devices,” DOI: https://doi.org/10.1109/IEDM50572.2025.11353681 This research was supported by the National Semiconductor Research Lab Core Technology Development Program funded by the Ministry of Science and ICT.          

KAIST Develops Liquid Powder That Enables Electron..

  <(From left) Dr. Osman Gul, Distinguished Professor Inkyu Park, Dr. Hye Jin Kim>     What if electronic circuits could be created simply by drawing lines with a pencil on paper or leaves—and then immediately applied to soft robots or skin-attached health monitoring devices? Korean researchers have developed an electronic materials technology that forms electrically conductive liquid metal in a fine powder form, allowing circuits to be drawn directly on a wide variety of surfaces. This technology presents new possibilities for next-generation flexible electronics, including applications on paper and plastic as well as in soft robotic systems and wearable devices. KAIST (President Kwang Hyung Lee) announced on the 15th of March that a research team led by Distinguished Professor Inkyu Park from the Department of Mechanical Engineering, in collaboration with Dr. Hye Jin Kim’s team at the Electronics and Telecommunications Research Institute (ETRI, President Seungchan Bang), has developed a liquid metal powder–based electronic material technology that allows electronic circuits to be directly drawn on desired surfaces. The material the researchers focused on is liquid metal, which flows like a liquid yet conducts electricity like a metal. However, conventional liquid metals have very high surface tension and poor wettability on most surfaces, making it difficult to create precise circuits at desired locations. They tend to spread or clump easily, requiring additional surface treatments or processing steps that limit practical applications. To overcome these limitations, the research team developed a new approach that converts liquid metal into fine powder particles. Each particle consists of liquid metal encapsulated by a thin oxide shell. Under normal conditions, the powder does not conduct electricity. The oxide layer forms naturally when the metal reacts with oxygen in the air, creating a very thin protective film. However, when light mechanical stimulation—such as brushing with a paintbrush or pressing with a finger—is applied, the oxide shell breaks and the metal particles connect with one another, enabling electrical conductivity. <Demonstration Video> In other words, the powder can be applied to a surface and only the required areas can be pressed to “activate” the electronic circuit, overcoming the spreading and patterning difficulties associated with conventional liquid metal circuits. One of the most notable features of this technology is its versatility across locations and materials. Without requiring any thermal processing, circuits can be created instantly on surfaces such as paper, glass, plastic, textiles, and even living plant leaves. The method significantly reduces issues such as spreading, sedimentation, and pattern distortion that were common in conventional liquid metal circuits, enabling stable circuit fabrication on diverse surfaces. Using this technology, the research team demonstrated practical applications including skin-mounted wireless health monitoring devices and flexible circuits for soft robots that can freely change shape. Because precise circuits can be fabricated on many surfaces without complex equipment, the technology is expected to find applications in next-generation electronic systems such as wearable healthcare devices, soft robotics, and flexible electronics. The technology also offers advantages in terms of environmental sustainability. After use, the circuits can be dissolved in water and chemically treated (for example with sodium hydroxide, NaOH) to recover the liquid metal. The recovered metal can then be converted back into powder form and reused. This capability makes the technology an environmentally friendly approach that can help reduce electronic waste. The powder also demonstrates stable performance. According to the research team, the developed powder maintains its functionality even after being stored at room temperature for more than a year and remains electrically intact after tens of thousands of bending or twisting cycles. These characteristics make it suitable for temporary electronic circuits that disappear after use as well as for customizable electronic devices. <Research Image(AI-generated image)> Distinguished Professor Inkyu Park stated, “This research enables electronic circuits to be fabricated as intuitively as drawing a picture, while also allowing recycling of the materials,” adding, “We expect it to be applied across various fields, including wearable computers and adaptive IoT systems that can change shape.” This research was led by Osman Gul, a postdoctoral researcher in the Department of Mechanical Engineering at KAIST, as the first author. The study was published online on December 9, 2025, in the international journal Advanced Functional Materials. The work was also selected as the Back Cover article of the journal in recognition of its significance. ※ Paper title: “Mechanochemically Activatable Liquid Metal Powders for Sustainable, Reconfigurable, and Versatile Electronics”, DOI: https://doi.org/10.1002/adfm.202527396 This research was supported by the Mid-Career Researcher Program of the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT, as well as by a project supported by the Korea Evaluation Institute of Industrial Technology (KEIT).  

KAIST Solves the 500-Year-Old ‘Pain’ Behind Michel..

  <(From Left) Ph.D candidate Minwoo Choi, Ph.D candidate Hyejoon Jun, Professor Hyoungsoo Kim>      More than 500 years ago, Michelangelo spent four years painting The Creation of Adam on the ceiling of the Sistine Chapel, struggling with paint dripping onto his face. He described the process as “closer to torture than painting.” Now, researchers at KAIST have developed a technology that can effectively “hold up falling paint.” Beyond ceiling paintings, this principle could help solve the problem of liquid films collapsing on inclined surfaces, with potential applications in precision coating, electronic circuit printing, 3D printing, and fluid control in space environments. KAIST (President Kwang Hyung Lee) announced on the 12th of March that a research team led by Professor Hyungsoo Kim of the Department of Mechanical Engineering has reinterpreted the fundamental cause of downward flow under gravity—known as gravitational instability—from the perspective of interfacial fluid mechanics＊ and proposed a method to control it by mixing a small amount of volatile liquid into a suspended liquid film. ＊Interfacial fluid mechanics: the study of the balance of microscopic forces acting at the surface of liquids. Why was it so difficult for Michelangelo to paint on the ceiling? When paint is applied to a ceiling, a thin liquid film forms. However, this film gradually becomes unstable due to gravity and eventually drips down. This phenomenon is common in everyday life. For example, when steam condenses on a bathroom ceiling, it first forms a thin layer of water that eventually gathers into droplets and falls. Similarly, droplets that appear on the ceiling of a refrigerator initially form a thin layer but gradually grow and begin to drip downward. This type of instability, where liquid accumulated on an upper surface collapses under gravity, is known as Rayleigh–Taylor instability. Until now, it has generally been considered unavoidable in the presence of gravity. The research team proposed mixing a small amount of volatile liquid into the suspended liquid film. As the volatile component evaporates, it changes the concentration distribution along the liquid surface, creating differences in surface tension. Surface tension is the force that pulls a liquid surface inward, which is why water droplets maintain a rounded shape. When differences in surface tension arise, the region with stronger tension pulls liquid toward itself from regions with weaker tension. This creates a surface flow known as the Marangoni effect. Through experiments and theoretical analysis, the researchers demonstrated that this surface flow can effectively hold the liquid in place and suppress the gravitational instability that would otherwise cause it to fall. A familiar example can illustrate this effect. If pepper powder is sprinkled evenly on the surface of water, it remains floating. However, if a drop of detergent is placed in the center, the pepper suddenly moves outward toward the edges. This happens because the detergent reduces the surface tension where it touches the water, allowing the surrounding regions with stronger surface tension to pull the liquid outward. As the surface flow develops, the pepper particles move along with it. In this study, evaporation of the volatile liquid created a similar surface tension difference. But instead of pushing particles outward like in the pepper example, the flow pulled the liquid upward, counteracting the force that would otherwise cause it to drip downward. As a result, under certain conditions the liquid film remained intact despite gravity. In some cases, the researchers even observed a new behavior in which droplets did not fall but the liquid film oscillated periodically. This demonstrates that gravitational instability can be actively controlled using only natural processes—such as liquid composition and evaporation—without any external energy input. This principle could enable thinner and more uniform liquid films in precision coating, printing, and layer-by-layer manufacturing processes, allowing stable coating even on tilted surfaces. It may also extend to technologies such as 3D printing and fluid control in specialized environments like space. In essence, the physical limitation that Michelangelo struggled with 500 years ago may now inspire future industrial technologies. <A fictional staged scene of Michelangelo painting The Creation of Adam (AI-generated image)> Professor Hyungsoo Kim stated, “Rayleigh–Taylor instability has long been considered unavoidable as long as gravity exists. This research is meaningful because it shows that gravitational instability can be actively controlled without external energy by utilizing natural processes such as liquid composition and evaporation.” He added, “This principle could extend beyond coating, printing, and layering processes to fluid control technologies in space environments.” This study was led by Minwoo Choi, an integrated master’s–PhD student in Mechanical Engineering, as the first author. The discovery, recognized as a new finding in the control of hydrodynamic instability, was published online on January 29 in the international journal Advanced Science (Wiley) and was selected as a Frontispiece article. ※ Paper title: “Evaporation-Driven Solutal Marangoni Control of Rayleigh–Taylor Instability in Inverted Films,” Authors: First author Minwoo Choi (KAIST), co-author Hyejoon Jun (KAIST), corresponding author Hyungsoo Kim (KAIST),  DOI: https://doi.org/10.1002/advs.202520343 This research was supported by the Mid-Career Researcher Program of the National Research Foundation of Korea (MSIT: 2021R1A2C2007835)