KAIST Develops Ultra-Precise Inspection Technology to Prevent Electric Vehicle Battery Fires
An ultra-precise inspection technology that could help prevent electric vehicle battery fires and improve battery safety has been developed. A KAIST research team has developed a method capable of detecting minute variations in battery electrode thickness that can contribute to thermal runaway with a precision equivalent to approximately one ten-thousandth the diameter of a human hair, all without disassembling or damaging the battery. The technology is expected to improve battery safety and quality by identifying invisible defects during the manufacturing process.
KAIST (President Choongsik Bae) announced on 23rd of July that a research team led by Professor Young-Jin Kim from the Department of Mechanical Engineering has developed a technology that measures the thickness of lithium-ion battery electrodes in a non-contact and non-destructive manner.
The technology combines terahertz waves (electromagnetic waves in the spectral region between light and radio waves) to obtain information from inside battery electrodes with an optical frequency comb, which divides the frequency of light into evenly spaced intervals like the markings on a ruler and serves as a reference for ultra-precise measurements.
The electrodes in lithium-ion batteries, which are widely used in electric vehicles, are essential components through which electric current flows. Even a slight variation in electrode thickness can cause current to become concentrated in certain areas when charging and discharging, generating heat. If the heat continues to accumulate, it may lead to thermal runaway, a phenomenon in which the internal temperature of a battery rises rapidly and can result in a fire or explosion. Maintaining uniform electrode thickness is therefore critically important during battery manufacturing.
Existing inspection technologies, however, have limitations when applied to production environments. X-ray computed tomography can provide detailed images of internal structures, but its relatively long inspection time makes it difficult to use on high-speed production lines. Ultrasonic acoustic microscopy requires direct contact with a liquid medium, while laser displacement sensors can perform rapid measurements but have difficulty precisely analyzing structures inside an electrode.
The research team overcame these limitations by combining optical frequency comb and terahertz technologies. The researchers first directed terahertz waves at a battery electrode and collected signals generated as the waves were repeatedly reflected within the electrode. They then used an optical frequency comb as a reference to analyze the signals with exceptionally high precision and calculate the electrode thickness. This enabled nanometer-scale measurements of the electrode’s internal structure without damaging the battery.
At the core of the technology is Fabry–Pérot interference, a regularly spaced interference pattern produced as terahertz waves repeatedly travel back and forth between the front and rear surfaces of an electrode. Much like measuring length by reading the markings on a ruler, the researchers precisely analyzed the interference pattern using the optical frequency comb as a reference to determine the electrode thickness.
As a result, the team successfully measured both the electrode thickness and its complex refractive index (a material’s optical property indicating how strongly it transmits and absorbs electromagnetic waves) in a single measurement without requiring a separate calibration process.
The researchers validated the technology using battery electrodes measuring between 50 and 150 micrometers in thickness, comparable to the diameter of a human hair. With a measurement time of just 0.2 seconds, the system detected thickness differences as small as 70.1 nanometers in the anode (approximately one fourteen-hundredth the diameter of a human hair) and 465.5 nanometers in the cathode. This measurement speed is considered sufficient for use on rapidly moving battery production lines.
When the measurement time was increased to 25.6 seconds, the precision improved further. The system distinguished differences as small as 7.8 nanometers in the anode (approximately one ten-thousandth the diameter of a human hair) and 25.2 nanometers in the cathode. This represents up to a 100-fold improvement in precision compared with conventional time-domain analysis methods, enabling the detection of thickness variations that are completely invisible to the naked eye.
The technology is not limited to measuring thickness at a single point. It can generate a three-dimensional map of thickness across an entire electrode and track gradual thickness variations in real time during production. The researchers also confirmed that the system could accurately measure an electrode tilted at an angle of approximately 45 degrees, demonstrating its potential for application to fast-moving, real-world battery manufacturing lines.
The study is significant because it presents a new inspection technology capable of identifying invisible microscopic defects during production without disassembling or damaging batteries. In addition to lithium-ion batteries, the technology is expected to serve as a key quality-control tool for manufacturing next-generation all-solid-state batteries, which use solid electrolytes instead of liquid electrolytes. By detecting defects at an early stage, the technology could improve battery safety and quality while enabling more stable manufacturing processes.
“This technology is an integrated metrology platform that can simultaneously measure electrode thickness and material properties without requiring a separate calibration process,” said Professor Kim. “We expect it to become a key technology for the real-time quality control of production lines for next-generation lithium-ion batteries and all-solid-state batteries.”
The study was led by Dr. Guseon Kang from the KAIST Department of Mechanical Engineering, currently with the Korea Institute of Industrial Technology, as the first author, with Professor Young-Jin Kim serving as the corresponding author. The research findings were published in the international journal Nature Communications on June 10.
Paper title: Nanometre-precision terahertz interferometry for battery electrode metrology
DOI: https://doi.org/10.1038/s41467-026-74193-8
This work was financially supported by the National Research Foundation of Korea (NRF) (RS-2024-00401786, RS-2025-00523273, RS-2025-25455397, RS-2026-25540567, and NRF-2022M1A3C2069728) and from the Korean government’s Defense Acquisition Program Administration (DAPA) (KRIT-CT-22-040).
KAIST: Dementia-Causing Substance Turns On a Therapeutic “Switch”
A substance that worsens dementia has become a “switch” that initiates treatment. KAIST researchers have developed a new therapeutic approach that uses hydrogen peroxide (H₂O₂), a reactive oxygen species that damages cells and increases in the brains of patients with Alzheimer’s disease, to activate a drug selectively in diseased brain tissue. The team also confirmed improvements in cognitive function through animal experiments, presenting a new possibility for next-generation dementia treatment.
KAIST announced on the 2nd that a research team led by Professor Mi Hee Lim of the Department of Chemistry, in collaboration with Professor Mingeun Kim of Chonnam National University, Dr. Chul-Ho Lee and Dr. Kyoung-Shim Kim of the Korea Research Institute of Bioscience and Biotechnology, and Dr. Young-Ho Lee of the Korea Basic Science Institute, has developed a prodrug that is activated selectively in the diseased brain in Alzheimer’s disease and confirmed its therapeutic effects through animal experiments.
A prodrug is a drug that initially has minimal therapeutic effect but is converted into an active therapeutic agent only under specific conditions inside the body. In this study, the prodrug was designed to be activated only when it encounters hydrogen peroxide, which increases in the brains of patients with Alzheimer’s disease, allowing it to function as a “smart therapeutic agent” that selectively acts in diseased brain tissue.
In the brains of Alzheimer’s disease patients, hydrogen peroxide, which damages cells, is elevated above normal levels. Until now, it has generally been regarded only as a harmful substance that should be removed. However, the research team devised a method to use it instead as a signal that activates a drug.
The prodrugs developed by the research team, BE-1 and BE-2, are designed to remain minimally reactive in a healthy brain. However, when they encounter hydrogen peroxide in a brain affected by dementia, they are converted into active therapeutic compounds, AP-1 and AP-2. Through this process, they reduce reactive oxygen species, including hydrogen peroxide, while also preventing amyloid beta (Aβ) peptides — peptides known as a major cause of dementia that accumulate in the brain and damage nerve cells — from aggregating into highly toxic clumps.
Using advanced analytical techniques, the research team confirmed that the activated drug alters the morphology of amyloid beta aggregates and suppresses their growth into large aggregates.
These effects were also confirmed in Alzheimer’s disease mouse models. The drug crossed the blood-brain barrier (BBB), a protective barrier that controls whether substances in the blood can enter the brain, and was converted into the therapeutic compound inside the diseased brain. In mice that received long-term drug administration, oxidative stress in the hippocampus, which is responsible for memory, was reduced, and amyloid beta accumulation in the brain also decreased. In behavioral experiments assessing the ability to recognize new objects and navigate mazes, cognitive function was also found to improve.
This study is significant in that the drug was designed to operate only where needed by using the environment of the diseased brain itself. This approach presents a new strategy for dementia treatment that can enhance therapeutic efficacy while reducing side effects, and it is expected to be applicable to the treatment of other neurodegenerative diseases, such as Parkinson’s disease.
Professor Mi Hee Lim of KAIST’s Department of Chemistry said, “This study is meaningful in that hydrogen peroxide, which had previously been regarded only as something to be eliminated, was used as a signal to activate a drug. We expect this strategy, which activates drugs in diseased tissue, to become a new platform for treating complex diseases such as Alzheimer’s disease more safely and effectively.”
This study was co-first-authored by Jimin Lee and Eunseo Hong, Ph.D. candidates in KAIST’s Department of Chemistry, and was published online on May 31, 2026, in the international journal Small (Impact Factor: 12.1, top 10% in the field of chemistry).
※ Paper title: A Prodrug Approach for Activity-Based Chemical Modulation toward Multiple Pathological Targets in Alzheimer’s Disease
DOI: 10.1002/smll.74013
This research was supported by the National Research Foundation of Korea’s Leader Researcher Program, Global Leading Research Center Program, Sejong Science Fellowship, Graduate Student Research Encouragement Program, and institutional programs of KRIBB and KBSI.
Graduate School of Global Digital Innovation (GDI) Hosts 'AI⁺ Global Prosperity Forum 2026'
The Graduate School of Global Digital Innovation (GDI) of KAIST will host the "AI⁺ Global Prosperity Forum 2026" on June 24 at the Chung Kunmo Conference Hall (5F), KAIST Academic Cultural Complex (E9).
KAIST Graduate School of Global Digital Innovation (GDI) is carrying out the "ICT Global Specialized Convergence Talent Cultivation Program" supported by the Ministry of Science and ICT and the Institute of Information & Communications Technology Planning & Evaluation (IITP). Since the launch of the Global IT Technology Program (ITTP) in 2006, GDI has grown into South Korea's representative global digital talent fostering platform over the past 20 years, nurturing approximately 260 government officials, public institution experts, and industry leaders from over 80 countries. GDI serves as a vehicle for global cooperation, sharing Korea's digital innovation experience and policy know-how with the international community, and promoting various collaborative projects such as international joint research, policy cooperation, and digital transformation projects based on its global network.
This forum, organized by GDI as part of the ICT Global Specialized Convergence Talent Cultivation Program under the theme 'Advancing Global AI Leadership Through Partnership and Innovation,' is designed to discuss global cooperation strategies for international partnership, digital transformation, and sustainable development in the AI era.
The event is expected to bring together approximately 60 government officials, international organization experts, researchers, and industry leaders from around 30 countries across Asia, Africa, Latin America, the Middle East, and Europe. Notably, representatives from the African Development Bank (AfDB), the Ministry of Communications and Digital Affairs of Indonesia, and various foreign governments, public institutions, and international organizations will participate to share AI governance, digital transformation, innovation policies, and international cooperation cases.
The forum will feature two main sessions:
Session 1: Global AI Partnership and Collaboration
Session 2: AI Policy, Governance, AI Innovation, and Applications
Participants will discuss global cooperation models in the AI era, digital transformation in the public sector, and methods for establishing AI policy and governance frameworks.
In addition, an 'AI⁺ Industry Showcase' featuring Korean AI and digital innovation enterprises alongside corporate exhibition booths will be operated simultaneously. Participating companies will introduce their innovative AI-based technologies and services, and seek opportunities for Proof of Concept (PoC), joint research, digital transformation projects, and overseas market expansion through business matching sessions with foreign government and public institution officials.
This forum is highly anticipated to serve as a global platform connecting AI technology, policy, industry, and international cooperation, while sharing Korea's AI capabilities and digital innovation experiences with the world and creating practical cooperative outcomes such as international joint research and digital transformation projects.
Seunghun Han, Head of the Graduate School of Global Digital Innovation, stated, "AI has moved beyond mere technology to become a core agenda for national development and international cooperation." He added, "We expect this forum to serve as a venue where policymakers, experts, and companies from around the world gather to explore future AI cooperation strategies and build new global partnerships."
The forum is open to any researchers, students, and the general public interested in AI and global cooperation through pre-registration (https://docs.google.com/forms/d/1QmYMqaD4uoT11NxUZb4ZSQBVgDxex5DJ3_4-eCoqgVI/edit).
※ Inquiries: KAIST Graduate School of Global Digital Innovation (gdi.adm@kaist.ac.kr / 042-350-6845)
Professor Yiyun Kang Selected as TED 2026 Main Stage Speaker
< Professor Yiyun Kang (Photo Credit: Ryan Lash / TED) >
KAIST announced on April 17th that Professor Yiyun Kang of the Department of Industrial Design has been selected as a speaker for the Main Stage at TED 2026, the world-renowned knowledge conference.
Founded in 1984 under the motto "Ideas Worth Spreading," TED is an American non-profit knowledge platform where scholars, innovators, and artists from around the globe gather annually to lead global discourse. Previous Korean speakers on the Main Stage include novelist Young-ha Kim (2012) and violinist Ji-hae Park (2013). In 2011, roboticist Professor Dennis Hong stood on the main conference stage as the first Korean-American speaker.
< TED Lecture Photo (Photo Credit: Ryan Lash / TED) >
Professor Kang’s selection is particularly significant as it marks the first time since TED moved its venue to Vancouver, Canada, in 2014 that a Korean national—an artist and scholar actively based in South Korea, rather than an overseas resident or defector—has been invited to the Main Stage. Furthermore, it marks the return of a Korean speaker to the main stage after a 12-year hiatus, serving as a symbolic milestone.
The TED 2026 annual conference is being held from April 13 to 17 at the Vancouver Convention Centre in Canada, under the theme "ALL OF US." Professor Kang took the Main Stage on April 15, the third day of the conference, to present visual insights and philosophical solutions for a future where Artificial Intelligence (AI), humans, and nature must coexist. The lecture video will be edited and released globally via the official TED website and YouTube channel this coming July.
In this talk, Professor Kang defines AI and the climate crisis as "problems we understand intellectually but fail to feel physically," noting that data- and information-centric communication methods often lower our sense of reality. She proposes the potential of art as a means to bridge this gap. Specifically, Professor Kang will demonstrate on stage how to transform complex challenges into visual and sensory experiences through cases from her own projects.
Notably, this presentation transcends traditional lecture formats, structured as an "Immersive Talk" that transforms the entire stage into an artistic space. Rather than just listening, the audience participates by experiencing the content with their entire bodies.
Professor Yiyun Kang is a world-class media artist and researcher who crosses the boundaries between sensation and technology, and materiality (physical forms) and immateriality (elements like light, video, and data). She leads the Experience Design Lab (XD Lab) at KAIST and has consistently explored the convergence of technology and art through collaborations with NASA, Google Arts & Culture, and the Victoria and Albert Museum (V&A).
"Humanity is currently at a critical turning point that will determine the coexistence of technology and nature," Professor Kang stated. "Through this TED stage, I aim to ensure that AI and the climate crisis are perceived not just as mere information, but as realities of our lives. I hope to create a practical opportunity to expand fragmented individual perceptions into collective human solidarity through the creative energy of art."
< TED 2026 Professor Yiyun Kang (Source: TED Website) >
IEEE President Professor Kramer Holds Special Lecture on Artificial Intelligence in the Electrical Engineering Department
Kathleen A. Kramer, President of the IEEE (Institute of Electrical and Electronics Engineers), the world's largest technical professional organization dedicated to electrical and electronic technology, visited our university on the 30th and delivered a special lecture under the theme, 'Drawing the Future of Artificial Intelligence Together.'
< IEEE Leadership and KAIST EE Meeting KITIS Director (Sung-Hyun Hong), KAIST EE Professors (Joonwoo Bae), (Ian Oakley), (Hye-Won Jeong), (Chang-Shik Choi), (Dong-Soo Han), Head of EE Department (Seunghyup Yoo), IEEE President (Kathleen A. Kramer), IEEE Senior Sales Director (Francis Staples), IEEE Regional Manager for APAC (Ira Tan), KAIST EE Professor (Hee-Jin Ahn), Head of Semiconductor System Engineering Department (Sung-Hwan Cho)>
Standing at the colloquium podium by invitation of the Department of Electrical Engineering (Head: Seung-Hyup Yoo), President Kramer emphasized based on IEEE's core vision, 'Advancing Technology for Humanity,' that "Artificial Intelligence (AI) is no longer a concept of the distant future; it has become a technology that is transforming human lives at the center of innovation."
< Photo of IEEE President's KAIST EE Colloquium Lecture >
She further added, "Technology must advance with human values at its core, and AI based on ethics and inclusiveness can lead to true innovation," sharing her insights on the direction of AI development and the social responsibility of technology.
Seung-Hyup Yoo, Head of the Department of Electrical Engineering, stated, "We expect President Kramer's visit to be a stepping stone that will not only widely promote our department's capabilities in advanced fields such as AI, semiconductors, signal processing, and robotics to the international academic community but also strengthen cooperation in various ways."
< Tea Meeting with the IEEE Leadership and the Vice Presidents . KITIS Director (Sung-Hyun Hong), IEEE Senior Sales Director (Francis Staples), IEEE President (Kathleen A. Kramer), KAIST Executive Vice President for Research (Sang Yup Lee), Head of EE Department (Seunghyup Yoo), IEEE Regional Manager for APAC (Ira Tan)>
Meanwhile, prior to the lecture, President Kramer paid a courtesy visit to Sang-Yup Lee, KAIST Executive Vice President for Research, and reaffirmed the commitment of both organizations to advancing sustainable technology and building an ethical and inclusive research ecosystem to contribute to a better life for humanity.
Ultra High Speed Optical Measurement Technology Developed
< (From left) Tae Jin Ha, CEO of VIRNECT, Kwang Hyung Lee, President of KAIST >
An open platform for industry-academia-research collaboration, which has accumulated K-Metaverse technology capabilities that break down the boundaries between reality and virtuality and share experiences beyond the limits of time and space, is expected to be built on our university campus.
Our university announced on the 13th that it’s signing an agreement for the establishment and operation of a 'Virtual Convergence Research Center' with the Graduate School of Metaverse and VIRNECT Co., Ltd. (CEO Tae Jin Ha), a domestic augmented/virtual reality (XR) specialized company and a startup founded by a KAIST alumnus.
The Virtual Convergence Research Center, which will be newly constructed on our university campus, plans to prepare for the future participation of related government-funded research institutes, and is expected to function as a national strategic hub that creates future growth engines for the Republic of Korea, going beyond simple industry-academia cooperation. VIRNECT Co., Ltd. plans to create the research center as an open research collaboration platform in which domestic and international industry, academia, and research institutes jointly participate with KAIST.
This research center is expected to experiment with the convergence of reality and virtuality and establish itself as a global hub for the 'K-Metaverse Innovation Ecosystem' where technology development, talent cultivation, and industrial diffusion are in a virtuous cycle.
VIRNECT Co., Ltd. was founded by KAIST alumnus Tae Jin Ha, listed on KOSDAQ in 2023, and won the CES Innovation Award for developing the industrial AI smart goggles 'VisionX'. It has grown into a representative domestic spatial computing company based on various industrial innovation technologies such as AI/XR solutions and digital twin. Synergistic co-prosperity with KAIST is anticipated through this collaboration.
Spatial computing and XR technology are areas where global big techs like Apple, Meta, Google, Microsoft, and Samsung are engaged in fierce competition for dominance, paying attention to them as the next-generation AI platforms. With major countries such as the US and China investing enormous capital and capabilities, the launch of the KAIST Virtual Convergence Research Center is evaluated as a strategic response for South Korea not to fall behind in the competition of the post-metaverse era.
The research center plans to lead both industrial productivity and social innovation as an R&BD (Research & Business Development) hub that integrates core technologies such as digital twin, metaverse, spatial/physical intelligence, and wearable XR. Furthermore, it will quickly verify the applicability to industrial sites and support the creation of new industries through a full-cycle system covering education, research, demonstration, commercialization, and diffusion.
Moreover, the research center will create national synergy by being closely linked with government policies. Strengthening the link between education and research, fostering a sustainable metaverse ecosystem, and expanding global leadership through an open industry-academia-research platform align with the government's strategy for advancing the virtual convergence industry.
< Executives from both organizations attending the signing ceremony >
VIRNECT CEO Tae Jin Ha said, "The long-term cooperation with KAIST is a stepping stone for us to leap forward as a game-changer in the global XR industry," adding, "We will strengthen virtual convergence technology competitiveness through research and education infrastructure and accelerate commercialization through demonstration."
Professor Woontack Woo, Dean of the Graduate School of Metaverse, emphasized, "The Virtual Convergence Research Center will serve as an open platform where industry, academia, and research institutes jointly experiment with K-Metaverse innovation, and a 'Meta Power Plant' that cultivates future core personnel and disseminates research results to the industry."
KAIST President Kwang Hyung Lee said, "This agreement is a strategic investment to secure global leadership by breaking down the boundaries between research and industry, going beyond simply creating a new research center," and "KAIST will spare no support for the research center."
With the future designation of the KAIST Virtual Convergence Research Center as a government-specialized graduate school/research center for the virtual convergence industry and increased industry cooperation, it will establish itself as a national innovation platform that concentrates South Korea's metaverse capabilities. This is expected to lead to the creation of new value for the future society and the strengthening of national competitiveness, going beyond simple technology development.
The Secret of Our Success Author Joseph Henrich to Deliver Special Lecture at KAIST
KAIST announced on the 19th that its Institute for Mind and Brain Sciences and the Department of Brain and Cognitive Science will be hosting a special lecture by world-renowned cultural evolution scholar, Professor Joseph Henrich of Harvard University. The free lecture will take place on the 22nd at the Conference Room on the 1st floor of the Meta-Convergence Hall at the KAIST main campus, with support from the Gikwan Foundation. The event is open to the public.
Professor Henrich, a professor in the Department of Human Evolutionary Biology at Harvard, is a leading authority on the evolution of culture and cooperation. He was recognized for his work on the origins of human cooperative behavior through a comparative study of 15 small-scale societies, earning the 2024 Panmure House Prize* (Adam Smith 300th Anniversary Prize) and the 2022 Hayek Book Prize.
* Panmure House Prize: An academic award established in honor of Adam Smith's scholarship, named after the building where he lived.
< Poster for Special Lecture by Professor Joseph Henrich of Harvard University >
His representative books, "The WEIRDest People in the World" and "The Secret of Our Success," have created a significant stir in both academia and the general public by offering new interpretations of the formation and development of human society from a cultural evolution perspective.
"The WEIRDest People in the World" emphasizes that human thought and behavior are products of specific cultural environments rather than universal truths. "The Secret of Our Success" presents a new perspective on how humanity, through cultural artifacts like language, tools, and institutions, has achieved unique success compared to other animals.
The lecture will be divided into two sessions: an academic seminar and a public lecture. The academic seminar, held from 10:00 AM to 11:30 AM, will be conducted in English on the topic of "Cultural Evolutionary Psychology, Kinship, and the Historical Origins of Modern Psychological Differences." It is intended for researchers, graduate students, and undergraduate students in related fields.
Following this, a public lecture will be held from 3:00 PM to 5:00 PM on the topic of "The Collective Brain: Social and Cultural Origins of Creativity." Professor Jeong Jae-seung of KAIST's Department of Brain and Cognitive Science will serve as the moderator, and simultaneous interpretation will be provided.
The lecture will cover how innovation and creativity are products of a collective intelligence formed by diverse people exchanging ideas through networks. It will also discuss how the pace of innovation within a population is determined by key factors such as community size, social connectivity, and cognitive diversity, and how these principles explain innovation in various social contexts, including cultural psychology, immigration, urbanization, and institutions. There will also be a Q&A session with the author of "The Secret of Our Success."
Regarding the lecture, Professor Henrich stated, "In human evolution, culture is not just a backdrop; it's the core driving force that makes us human. Through this lecture, I want to share how we have learned from each other, cooperated, and developed knowledge and institutions. I especially look forward to having a deep conversation with the audience about the evolutionary significance of the passion for education and learning culture in Korean society."
Professor Jeong Jae-seung of KAIST's Department of Brain and Cognitive Science said, "This lecture was organized to explore how the human mind and brain have evolved through interaction with culture. It will be a valuable opportunity to hear the insights of a world-renowned scholar from the interdisciplinary perspective of meditation science and brain and cognitive science."
To register for the event, you can use the link (https://forms.gle/7TW9FAKv1qgA3dBBA) or the QR code on the poster. For inquiries, please contact the KAIST Institute for Mind and Brain Sciences at 042-350-1361.
KAIST researcher Se Jin Park develops 'SpeechSSM,' opening up possibilities for a 24-hour AI voice assistant.
<(From Left)Prof. Yong Man Ro and Ph.D. candidate Sejin Park>
Se Jin Park, a researcher from Professor Yong Man Ro’s team at KAIST, has announced 'SpeechSSM', a spoken language model capable of generating long-duration speech that sounds natural and remains consistent.
An efficient processing technique based on linear sequence modeling overcomes the limitations of existing spoken language models, enabling high-quality speech generation without time constraints.
It is expected to be widely used in podcasts, audiobooks, and voice assistants due to its ability to generate natural, long-duration speech like humans.
Recently, Spoken Language Models (SLMs) have been spotlighted as next-generation technology that surpasses the limitations of text-based language models by learning human speech without text to understand and generate linguistic and non-linguistic information. However, existing models showed significant limitations in generating long-duration content required for podcasts, audiobooks, and voice assistants. Now, KAIST researcher has succeeded in overcoming these limitations by developing 'SpeechSSM,' which enables consistent and natural speech generation without time constraints.
KAIST(President Kwang Hyung Lee) announced on the 3rd of July that Ph.D. candidate Sejin Park from Professor Yong Man Ro's research team in the School of Electrical Engineering has developed 'SpeechSSM,' a spoken. a spoken language model capable of generating long-duration speech.
This research is set to be presented as an oral paper at ICML (International Conference on Machine Learning) 2025, one of the top machine learning conferences, selected among approximately 1% of all submitted papers. This not only proves outstanding research ability but also serves as an opportunity to once again demonstrate KAIST's world-leading AI research capabilities.
A major advantage of Spoken Language Models (SLMs) is their ability to directly process speech without intermediate text conversion, leveraging the unique acoustic characteristics of human speakers, allowing for the rapid generation of high-quality speech even in large-scale models.
However, existing models faced difficulties in maintaining semantic and speaker consistency for long-duration speech due to increased 'speech token resolution' and memory consumption when capturing very detailed information by breaking down speech into fine fragments.
To solve this problem, Se Jin Park developed 'SpeechSSM,' a spoken language model using a Hybrid State-Space Model, designed to efficiently process and generate long speech sequences.
This model employs a 'hybrid structure' that alternately places 'attention layers' focusing on recent information and 'recurrent layers' that remember the overall narrative flow (long-term context). This allows the story to flow smoothly without losing coherence even when generating speech for a long time. Furthermore, memory usage and computational load do not increase sharply with input length, enabling stable and efficient learning and the generation of long-duration speech.
SpeechSSM effectively processes unbounded speech sequences by dividing speech data into short, fixed units (windows), processing each unit independently, and then combining them to create long speech.
Additionally, in the speech generation phase, it uses a 'Non-Autoregressive' audio synthesis model (SoundStorm), which rapidly generates multiple parts at once instead of slowly creating one character or one word at a time, enabling the fast generation of high-quality speech.
While existing models typically evaluated short speech models of about 10 seconds, Se Jin Park created new evaluation tasks for speech generation based on their self-built benchmark dataset, 'LibriSpeech-Long,' capable of generating up to 16 minutes of speech.
Compared to PPL (Perplexity), an existing speech model evaluation metric that only indicates grammatical correctness, she proposed new evaluation metrics such as 'SC-L (semantic coherence over time)' to assess content coherence over time, and 'N-MOS-T (naturalness mean opinion score over time)' to evaluate naturalness over time, enabling more effective and precise evaluation.
Through these new evaluations, it was confirmed that speech generated by the SpeechSSM spoken language model consistently featured specific individuals mentioned in the initial prompt, and new characters and events unfolded naturally and contextually consistently, despite long-duration generation. This contrasts sharply with existing models, which tended to easily lose their topic and exhibit repetition during long-duration generation.
PhD candidate Sejin Park explained, "Existing spoken language models had limitations in long-duration generation, so our goal was to develop a spoken language model capable of generating long-duration speech for actual human use." She added, "This research achievement is expected to greatly contribute to various types of voice content creation and voice AI fields like voice assistants, by maintaining consistent content in long contexts and responding more efficiently and quickly in real time than existing methods."
This research, with Se Jin Park as the first author, was conducted in collaboration with Google DeepMind and is scheduled to be presented as an oral presentation at ICML (International Conference on Machine Learning) 2025 on July 16th.
Paper Title: Long-Form Speech Generation with Spoken Language Models
DOI: 10.48550/arXiv.2412.18603
Ph.D. candidate Se Jin Park has demonstrated outstanding research capabilities as a member of Professor Yong Man Ro's MLLM (multimodal large language model) research team, through her work integrating vision, speech, and language. Her achievements include a spotlight paper presentation at 2024 CVPR (Computer Vision and Pattern Recognition) and an Outstanding Paper Award at 2024 ACL (Association for Computational Linguistics).
For more information, you can refer to the publication and accompanying demo: SpeechSSM Publications.
Simultaneous Analysis of 21 Chemical Reactions... AI to Transform New Drug Development
< Photo 1. (From left) Professor Hyunwoo Kim and students Donghun Kim and Gyeongseon Choi in the Integrated M.S./Ph.D. program of the Department of Chemistry >
Thalidomide, a drug once used to alleviate morning sickness in pregnant women, exhibits distinct properties due to its optical isomers* in the body: one isomer has a sedative effect, while the other causes severe side effects like birth defects. As this example illustrates, precise organic synthesis techniques, which selectively synthesize only the desired optical isomer, are crucial in new drug development. Overcoming the traditional methods that struggled with simultaneously analyzing multiple reactants, our research team has developed the world's first technology to precisely analyze 21 types of reactants simultaneously. This breakthrough is expected to make a significant contribution to new drug development utilizing AI and robots.
*Optical Isomers: A pair of molecules with the same chemical formula that are mirror images of each other and cannot be superimposed due to their asymmetric structure. This is analogous to a left and right hand, which are similar in form but cannot be perfectly overlaid.
KAIST's Professor Hyunwoo Kim's research team in the Department of Chemistry announced on the 16th that they have developed an innovative optical isomer analysis technology suitable for the era of AI-driven autonomous synthesis*. This research is the world's first technology to precisely analyze asymmetric catalytic reactions involving multiple reactants simultaneously using high-resolution fluorine nuclear magnetic resonance spectroscopy (19F NMR). It is expected to make groundbreaking contributions to various fields, including new drug development and catalyst optimization.
*AI-driven Autonomous Synthesis: An advanced technology that automates and optimizes chemical substance synthesis processes using artificial intelligence (AI). It is gaining attention as a core element for realizing automated and intelligent research environments in future laboratories. AI predicts and adjusts experimental conditions, interprets results, and designs subsequent experiments independently, minimizing human intervention in repetitive experiments and significantly increasing research efficiency and innovativeness.
Currently, while autonomous synthesis systems can automate everything from reaction design to execution, reaction analysis still relies on individual processing using traditional equipment. This leads to slower speeds and bottlenecks, making it unsuitable for high-speed repetitive experiments.
Furthermore, multi-substrate simultaneous screening techniques proposed in the 1990s garnered attention as a strategy to maximize reaction analysis efficiency. However, limitations of existing chromatography-based analysis methods restricted the number of applicable substrates. In asymmetric synthesis reactions, which selectively synthesize only the desired optical isomer, simultaneously analyzing more than 10 types of substrates was nearly impossible.
< Figure 1. Conventional organic reaction evaluation methods follow a process of deriving optimal reaction conditions using a single substrate, then expanding the substrate scope one by one under those conditions, leaving potential reaction areas unexplored. To overcome this, high-throughput screening is introduced to broadly explore catalyst reactivity for various substrates. When combined with multi-substrate screening, this approach allows for a much broader and more systematic understanding of reaction scope and trends. >
To overcome these limitations, the research team developed a 19F NMR-based multi-substrate simultaneous screening technology. This method involves performing asymmetric catalytic reactions with multiple reactants in a single reaction vessel, introducing a fluorine functional group into the products, and then applying their self-developed chiral cobalt reagent to clearly quantify all optical isomers using 19F NMR.
Utilizing the excellent resolution and sensitivity of 19F NMR, the research team successfully performed asymmetric synthesis reactions of 21 substrates simultaneously in a single reaction vessel and quantitatively measured the product yield and optical isomer ratio without any separate purification steps.
Professor Hyunwoo Kim stated, "While anyone can perform asymmetric synthesis reactions with multiple substrates in one reactor, accurately analyzing all the products has been a challenging problem to solve until now. We expect that achieving world-class multi-substrate screening analysis technology will greatly contribute to enhancing the analytical capabilities of AI-driven autonomous synthesis platforms."
< Figure 2. A method for analyzing multi-substrate asymmetric catalytic reactions, where different substrates react simultaneously in a single reactor, using fluorine nuclear magnetic resonance has been implemented. By utilizing the characteristics of fluorine nuclear magnetic resonance, which has a clean background signal and a wide chemical shift range, the reactivity of each substrate can be quantitatively analyzed. It is also shown that the optical activity of all reactants can be simultaneously measured using a cobalt metal complex. >
He further added, "This research provides a technology that can rapidly verify the efficiency and selectivity of asymmetric catalytic reactions essential for new drug development, and it is expected to be utilized as a core analytical tool for AI-driven autonomous research."
< Figure 3. It can be seen that in a multi-substrate reductive amination reaction using a total of 21 substrates, the yield and optical activity of the reactants according to the catalyst system were simultaneously measured using a fluorine nuclear magnetic resonance-based analysis platform. The yield of each reactant is indicated by color saturation, and the optical activity by numbers. >
Donghun Kim (first author, Integrated M.S./Ph.D. program) and Gyeongseon Choi (second author, Integrated M.S./Ph.D. program) from the KAIST Department of Chemistry participated in this research. The study was published online in the Journal of the American Chemical Society on May 27, 2025.※ Paper Title: One-pot Multisubstrate Screening for Asymmetric Catalysis Enabled by 19F NMR-based Simultaneous Chiral Analysis※ DOI: 10.1021/jacs.5c03446
This research was supported by the National Research Foundation of Korea's Mid-Career Researcher Program, the Asymmetric Catalytic Reaction Design Center, and the KAIST KC30 Project.
< Figure 4. Conceptual diagram of performing multi-substrate screening reactions and utilizing fluorine nuclear magnetic resonance spectroscopy. >
High-Resolution Spectrometer that Fits into Smartphones Developed by KAIST Researchers
- Professor Mooseok Jang's research team at the Department of Bio and Brain Engineering develops an ultra-compact, high-resolution spectrometer using 'double-layer disordered metasurfaces' that generate unique random patterns depending on light's color.
- Unlike conventional dispersion-based spectrometers that were difficult to apply to portable devices, this new concept spectrometer technology achieves 1nm-level high resolution in a device smaller than 1cm, comparable in size to a fingernail.
- It can be utilized as a built-in spectrometer in smartphones and wearable devices in the future, and can be expanded to advanced optical technologies such as hyperspectral imaging and ultrafast imaging.
< Photo 1. (From left) Professor Mooseok Jang, Dong-gu Lee (Ph.D. candidate), Gookho Song (Ph.D. candidate) >
Color, as the way light's wavelength is perceived by the human eye, goes beyond a simple aesthetic element, containing important scientific information like a substance's composition or state. Spectrometers are optical devices that analyze material properties by decomposing light into its constituent wavelengths, and they are widely used in various scientific and industrial fields, including material analysis, chemical component detection, and life science research. Existing high-resolution spectrometers were large and complex, making them difficult for widespread daily use. However, thanks to the ultra-compact, high-resolution spectrometer developed by KAIST researchers, it is now expected that light's color information can be utilized even within smartphones or wearable devices.
KAIST (President Kwang Hyung Lee) announced on the 13th that Professor Mooseok Jang's research team at the Department of Bio and Brain Engineering has successfully developed a reconstruction-based spectrometer technology using double-layer disordered metasurfaces*.
*Double-layer disordered metasurface: An innovative optical device that complexly scatters light through two layers of disordered nanostructures, creating unique and predictable speckle patterns for each wavelength.
Existing high-resolution spectrometers have a large form factor, on the order of tens of centimeters, and require complex calibration processes to maintain accuracy. This fundamentally stems from the operating principle of traditional dispersive elements, such as gratings and prisms, which separate light wavelengths along the propagation direction, much like a rainbow separates colors. Consequently, despite the potential for light's color information to be widely useful in daily life, spectroscopic technology has been limited to laboratory or industrial manufacturing environments.
< Figure 1. Through a simple structure consisting of a double layer of disordered metasurfaces and an image sensor, it was shown that speckles of predictable spectral channels with high spectral resolution can be generated in a compact form factor. The high similarity between the measured and calculated speckles was used to solve the inverse problem and verify the ability to reconstruct the spectrum. >
The research team devised a method that departs from the conventional spectroscopic paradigm of using diffraction gratings or prisms, which establish a one-to-one correspondence between light's color information and its propagation direction, by utilizing designed disordered structures as optical components. In this process, they employed metasurfaces, which can freely control the light propagation process using structures tens to hundreds of nanometers in size, to accurately implement 'complex random patterns (speckle*)'.
*Speckle: An irregular pattern of light intensity created by the interference of multiple wavefronts of light.
Specifically, they developed a method that involves implementing a double-layer disordered metasurface to generate wavelength-specific speckle patterns and then reconstructing precise color information (wavelength) of the light from the random patterns measured by a camera.
As a result, they successfully developed a new concept spectrometer technology that can accurately measure light across a broad range of visible to infrared (440-1,300nm) with a high resolution of 1 nanometer (nm) in a device smaller than a fingernail (less than 1cm) using only a single image capture.
< Figure 2. A disordered metasurface is a metasurface with irregularly arranged structures ranging from tens to hundreds of nanometers in size. In a double-layer structure, a propagation space is placed between the two metasurfaces to control the output speckle with high degrees of freedom, thereby achieving a spectral resolution of 1 nm even in a form factor smaller than 1 cm. >
Dong-gu Lee, a lead author of this study, stated, "This technology is implemented in a way that is directly integrated with commercial image sensors, and we expect that it will enable easy acquisition and utilization of light's wavelength information in daily life when built into mobile devices in the future."
Professor Mooseok Jang said, "This technology overcomes the limitations of existing RGB three-color based machine vision fields, which only distinguish and recognize three color components (red, green, blue), and has diverse applications. We anticipate various applied research for this technology, which expands the horizon of laboratory-level technology to daily-level machine vision technology for applications such as food component analysis, crop health diagnosis, skin health measurement, environmental pollution detection, and bio/medical diagnostics." He added, "Furthermore, it can be extended to various advanced optical technologies such as hyperspectral imaging, which records wavelength and spatial information simultaneously with high resolution, 3D optical trapping technology, which precisely controls light of multiple wavelengths into desired forms, and ultrafast imaging technology, which captures phenomena occurring in very short periods."
This research was collaboratively led by Dong-gu Lee (Ph.D. candidate) and Gookho Song (Ph.D. candidate) from the KAIST Department of Bio and Brain Engineering as co-first authors, with Professor Mooseok Jang as the corresponding author. The findings were published online in the international journal Science Advances on May 28, 2025.* Paper Title: Reconstructive spectrometer using double-layer disordered metasurfaces* DOI: 10.1126/sciadv.adv2376
This research was supported by the Samsung Research Funding and Incubation Center of Samsung Electronics grant, the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT), and the Bio & Medical Technology Development Program of the National Research Foundation (NRF) funded by the Korean government (MSIT).
Ultralight advanced material developed by KAIST and U of Toronto
< (From left) Professor Seunghwa Ryu of KAIST Department of Mechanical Engineering, Professor Tobin Filleter of the University of Toronto, Dr. Jinwook Yeo of KAIST, and Dr. Peter Serles of the University of Toronto >
Recently, in advanced industries such as automobiles, aerospace, and mobility, there has been increasing demand for materials that achieve weight reduction while maintaining excellent mechanical properties. An international joint research team has developed an ultralight, high-strength material utilizing nanostructures, presenting the potential for various industrial applications through customized design in the future.
KAIST (represented by President Kwang Hyung Lee) announced on the 18th of February that a research team led by Professor Seunghwa Ryu from the Department of Mechanical Engineering, in collaboration with Professor Tobin Filleter from the University of Toronto, has developed a nano-lattice structure that maximizes lightweight properties while maintaining high stiffness and strength.
In this study, the research team optimized the beam shape of the lattice structure to maintain its lightweight characteristics while maximizing stiffness and strength.
Particularly, using a multi-objective Bayesian optimization algorithm*, the team conducted an optimal design process that simultaneously considers tensile and shear stiffness improvement and weight reduction. They demonstrated that the optimal lattice structure could be predicted and designed with significantly less data (about 400 data points) compared to conventional methods.
*Multi-objective Bayesian optimization algorithm: A method that finds the optimal solution while considering multiple objectives simultaneously. It efficiently collects data and predicts results even under conditions of uncertainty.
< Figure 1. Multi-objective Bayesian optimization for generative design of carbon nanolattices with high compressive stiffness and strength at low density. The upper is the illustration of process workflow. The lower part shows top four MBO CFCC geometries with their 2D Bézier curves. (The optimized structure is predicted and designed with much less data (approximately 400) than the conventional method >
Furthermore, to maximize the effect where mechanical properties improve as size decreases at the nanoscale, the research team utilized pyrolytic carbon* material to implement an ultralight, high-strength, high-stiffness nano-lattice structure.
*Pyrolytic carbon: A carbon material obtained by decomposing organic substances at high temperatures. It has excellent heat resistance and strength, making it widely used in industries such as semiconductor equipment coatings and artificial joint coatings, where it must withstand high temperatures without deformation.
For this, the team applied two-photon polymerization (2PP) technology* to precisely fabricate complex nano-lattice structures, and mechanical performance evaluations confirmed that the developed structure simultaneously possesses strength comparable to steel and the lightness of Styrofoam.
*Two-photon polymerization (2PP) technology: An advanced optical manufacturing technique based on the principle that polymerization occurs only when two photons of a specific wavelength are absorbed simultaneously.
Additionally, the research team demonstrated that multi-focus two-photon polymerization (multi-focus 2PP) technology enables the fabrication of millimeter-scale structures while maintaining nanoscale precision.
Professor Seunghwa Ryu explained, "This technology innovatively solves the stress concentration issue, which has been a limitation of conventional design methods, through three-dimensional nano-lattice structures, achieving both ultralight weight and high strength in material development."
< Figure 2. FESEM image of the fabricated nano-lattice structure and (bottom right) the macroscopic nanolattice resting on a bubble >
He further emphasized, "By integrating data-driven optimal design with precision 3D printing technology, this development not only meets the demand for lightweight materials in the aerospace and automotive industries but also opens possibilities for various industrial applications through customized design."
This study was led by Dr. Peter Serles of the Department of Mechanical & Industrial Engineering at University of Toronto and Dr. Jinwook Yeo from KAIST as co-first authors, with Professor Seunghwa Ryu and Professor Tobin Filleter as corresponding authors.
The research was published on January 23, 2025 in the international journal Advanced Materials (Paper title: “Ultrahigh Specific Strength by Bayesian Optimization of Lightweight Carbon Nanolattices”).
DOI: https://doi.org/10.1002/adma.202410651
This research was supported by the Multiphase Materials Innovation Manufacturing Research Center (an ERC program) funded by the Ministry of Science and ICT, the M3DT (Medical Device Digital Development Tool) project funded by the Ministry of Food and Drug Safety, and the KAIST International Collaboration Program.
KAIST Develops Insect-Eye-Inspired Camera Capturing 9,120 Frames Per Second
< (From left) Bio and Brain Engineering PhD Student Jae-Myeong Kwon, Professor Ki-Hun Jeong, PhD Student Hyun-Kyung Kim, PhD Student Young-Gil Cha, and Professor Min H. Kim of the School of Computing >
The compound eyes of insects can detect fast-moving objects in parallel and, in low-light conditions, enhance sensitivity by integrating signals over time to determine motion. Inspired by these biological mechanisms, KAIST researchers have successfully developed a low-cost, high-speed camera that overcomes the limitations of frame rate and sensitivity faced by conventional high-speed cameras.
KAIST (represented by President Kwang Hyung Lee) announced on the 16th of January that a research team led by Professors Ki-Hun Jeong (Department of Bio and Brain Engineering) and Min H. Kim (School of Computing) has developed a novel bio-inspired camera capable of ultra-high-speed imaging with high sensitivity by mimicking the visual structure of insect eyes.
High-quality imaging under high-speed and low-light conditions is a critical challenge in many applications. While conventional high-speed cameras excel in capturing fast motion, their sensitivity decreases as frame rates increase because the time available to collect light is reduced.
To address this issue, the research team adopted an approach similar to insect vision, utilizing multiple optical channels and temporal summation. Unlike traditional monocular camera systems, the bio-inspired camera employs a compound-eye-like structure that allows for the parallel acquisition of frames from different time intervals.
< Figure 1. (A) Vision in a fast-eyed insect. Reflected light from swiftly moving objects sequentially stimulates the photoreceptors along the individual optical channels called ommatidia, of which the visual signals are separately and parallelly processed via the lamina and medulla. Each neural response is temporally summed to enhance the visual signals. The parallel processing and temporal summation allow fast and low-light imaging in dim light. (B) High-speed and high-sensitivity microlens array camera (HS-MAC). A rolling shutter image sensor is utilized to simultaneously acquire multiple frames by channel division, and temporal summation is performed in parallel to realize high speed and sensitivity even in a low-light environment. In addition, the frame components of a single fragmented array image are stitched into a single blurred frame, which is subsequently deblurred by compressive image reconstruction. >
During this process, light is accumulated over overlapping time periods for each frame, increasing the signal-to-noise ratio. The researchers demonstrated that their bio-inspired camera could capture objects up to 40 times dimmer than those detectable by conventional high-speed cameras.
The team also introduced a "channel-splitting" technique to significantly enhance the camera's speed, achieving frame rates thousands of times faster than those supported by the image sensors used in packaging. Additionally, a "compressed image restoration" algorithm was employed to eliminate blur caused by frame integration and reconstruct sharp images.
The resulting bio-inspired camera is less than one millimeter thick and extremely compact, capable of capturing 9,120 frames per second while providing clear images in low-light conditions.
< Figure 2. A high-speed, high-sensitivity biomimetic camera packaged in an image sensor. It is made small enough to fit on a finger, with a thickness of less than 1 mm. >
The research team plans to extend this technology to develop advanced image processing algorithms for 3D imaging and super-resolution imaging, aiming for applications in biomedical imaging, mobile devices, and various other camera technologies.
Hyun-Kyung Kim, a doctoral student in the Department of Bio and Brain Engineering at KAIST and the study's first author, stated, “We have experimentally validated that the insect-eye-inspired camera delivers outstanding performance in high-speed and low-light imaging despite its small size. This camera opens up possibilities for diverse applications in portable camera systems, security surveillance, and medical imaging.”
< Figure 3. Rotating plate and flame captured using the high-speed, high-sensitivity biomimetic camera. The rotating plate at 1,950 rpm was accurately captured at 9,120 fps. In addition, the pinch-off of the flame with a faint intensity of 880 µlux was accurately captured at 1,020 fps. >
This research was published in the international journal Science Advances in January 2025 (Paper Title: “Biologically-inspired microlens array camera for high-speed and high-sensitivity imaging”).
DOI: https://doi.org/10.1126/sciadv.ads3389
This study was supported by the Korea Research Institute for Defense Technology Planning and Advancement (KRIT) of the Defense Acquisition Program Administration (DAPA), the Ministry of Science and ICT, and the Ministry of Trade, Industry and Energy (MOTIE).