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KAIST Develops Low-Temperature Technique for Growing Crystal-Aligned Semiconductor Films
Building next-generation semiconductors and low-power electronic devices requires precisely stacking materials with different functions. In this process, it is essential to preserve each material's intrinsic properties, as well as the interface where the two materials meet, without damage. Layered van der Waals materials, including transition metal dichalcogenides (TMDs), have attracted considerable attention as next-generation semiconductor platforms because their layers interact through weak forces, enabling different materials to be stacked while maintaining atomically clean interfaces.
KAIST (President Choongsik Bae) announced on the 27th of July that a research team led by Professor Joonki Suh from the Department of Chemical and Biomolecular Engineering, in collaboration with Professor Bonggeun Shong's team at Hanyang University and Professor Yimo Han's team at Rice University in the United States, has developed a new semiconductor manufacturing technique based on atomic layer deposition (ALD). ALD is a thin-film deposition process in which semiconductor precursor are supplied sequentially, enabling uniform thin films to be deposited with atomic-level control over their thickness.
The research team focused on van der Waals materials. These two-dimensional semiconductor materials consist of multiple atomic layers held together by weak interlayer forces, allowing them to be peeled apart into sheets as thin as paper. Because different materials can be freely stacked, van der Waals materials are attracting attention as key building blocks for next-generation AI chips and ultra-low-power semiconductor devices.
However, their chemically stable surfaces make it difficult to grow new semiconductor layers in a uniformly aligned orientation. This challenge becomes even greater at lower temperatures, where atoms tend to nucleate and grow in random directions, making it difficult to produce high-performance semiconductor films.
The research team developed a new method that allows tellurium (Te)-containing precursors—molecular building blocks used to fabricate semiconductors—to move freely across the surface, find the most energetically stable positions, and form a thin film.
Tellurium is attracting attention as a key material for next-generation semiconductors and optoelectronic devices, including photodetectors and light-emitting diodes (LEDs), because it combines highly direction-dependent electrical conductivity with excellent light-controlling properties.
Using this approach, the research team succeeded in achieving epitaxial growth of tellurium uniformly in a single direction on van der Waals materials— next-generation two-dimensional semiconductor materials composed of multiple atomically thin layers stacked like sheets of paper— at a low temperature of 150°C using ALD. In epitaxial growth, a new semiconductor film grows in an ordered manner following the atomic arrangement of the underlying crystal, enabling the precise fabrication of high-quality semiconductor films. This process is comparable to stacking bricks neatly in the same direction rather than placing them randomly, which can improve electrical transport and enhance semiconductor performance.
The researchers also confirmed that the technology could be applied to a range of van der Waals materials, including tungsten diselenide (WSe2), molybdenum disulfide (MoSS), rhenium diselenide (ReSe2), and mica. This demonstrates that the method is not limited to a single material but can be broadly used with various next-generation semiconductor materials.
The team further used the resulting semiconductor films to fabricate transistors, key semiconductor devices that control the flow of electrical current, as well as optoelectronic devices that detect or emit light. This demonstrated that the new manufacturing technology is not confined to laboratory-scale material growth but can also be applied to the fabrication of functional semiconductor devices.
"This study is the first to demonstrate that high-quality semiconductor films can be grown on van der Waals materials at low temperature without damaging the underlying materials," said Professor Suh. "We expect this technology to serve as a key manufacturing platform for integrating a wide range of next-generation semiconductors on a single chip," he added.
The study, with Changhwan Kim, a doctoral student, as first author and Professor Suh as corresponding author, was published in the journal Science Advances on July 24.
Paper title: Van der Waals template-encoded soft epitaxy of tellurium enabled by atomic layer deposition
DOI: 10.1126/sciadv.aef1430
Author information: Changhwan Kim (Korea Advanced Institute of Science and Technology / Ulsan National Institute of Science and Technology, first author) and Joonki Suh (Korea Advanced Institute of Science and Technology, corresponding author)
This research was supported by the National Research Foundation of Korea, under the Ministry of Science and ICT.
2026.07.27 View 664 -
KAIST identifies a molecular “switch” that activates cell growth signaling, suggesting a potential basis for next-generation anticancer therapy
Cells carry their own growth switches. When enough nutrients—amino acids in particular—are available, cells flip this switch on and begin to grow. Researchers at KAIST and Yonsei University have now uncovered the molecular mechanism by which amino acid signals activate this cellular growth switch. The findings are expected to open a new avenue for anticancer therapies that target abnormal growth signaling in tumor cells.
KAIST (President Choongsik Bae) announced on July 26 that a research team led by Professors Hee-Sung Park and Jin Young Kang from the Department of Chemistry, working with Professor Sunghoon Kim's team from Yonsei University, has identified a molecular mechanism that links amino acid stimulation to mTORC1-dependent growth signaling.
Cells continually monitor whether enough amino acids—the basic building blocks of proteins—are available in their surroundings, and adjust their growth, protein synthesis, and energy use accordingly. Central to this process is mTORC1 (mammalian Target of Rapamycin Complex 1), a protein complex that functions as the cell's growth switch.
mTORC1 promotes cell growth, protein synthesis, and metabolism when nutrients and energy are abundant. But when mTORC1 becomes excessively active, cells can grow and proliferate beyond what is needed—a pattern of dysregulation observed in numerous cancers. For this reason, mTORC1 has long been considered a prime target for anticancer drug development. Exactly how cells detect external nutrient cues and translate them into mTORC1 activation, however, has remained incompletely understood.
The research team focused on the multi-tRNA synthetase complex (MSC), a large protein assembly composed of multiple aminoacyl-tRNA synthetases and scaffold proteins. While aminoacyl-tRNA synthetases are best known for their essential role in protein synthesis – attaching specific amino acids to their cognate tRNAs – the team showed that, in response to amino acid stimulation the MSC releases LARS1, thereby linking nutrient availability to growth signaling.
The key player within the MSC turned out to be a protein called LARS1 (leucyl-tRNA synthetase 1), an enzyme that attaches leucine to its corresponding tRNA and also functions as an intracellular leucine sensor. When cells receive a signal that nutrients are sufficient, LARS1 undergoes phosphorylation—a modification in which a small chemical tag is attached to a protein, altering its function or binding behavior.
The relationship can be pictured this way: the MSC is a control center where multiple proteins wait on standby, and LARS1 is the field agent dispatched to flip on the growth switch. When nutrients become abundant, LARS1 receives a phosphorylation "deployment signal," dissociates from IARS1, the protein that anchors LARS1 to the MSC, and is thereby released from the complex. The freed LARS1 then goes on to activate mTORC1.
In other words, when nutrients are scarce, LARS1 stays bound within the MSC and the growth signal remains off. Once nutrients become sufficient, LARS1 is released from the MSC and switches on mTORC1.
To investigate the structural basis of this process, the team used cryo-electron microscopy (cryo-EM), a technique that visualizes protein complexes in three dimensions in near-atomic resolution by rapidly freezing samples at extremely low temperatures. This allowed the researchers to determine how LARS1 and IARS1 bind to each other and to structurally explain how phosphorylation could disrupt their interaction.
The results showed that LARS1 and IARS1 are normally bound tightly, but amino acid stimulation induces the phosphorylation of LARS1, weakening its interaction with IARS1. This allows LARS1 to dissociate from the MSC and activate mTORC1.
The researchers also engineered phosphomimetic LARS1 variants—mutant proteins designed to imitate the phosphorylated state—and found that these variants substantially enhanced mTORC1 activity. This confirmed that the phosphorylation of LARS1 functions as the key molecular switch converting a nutrient signal into a cell growth signal.
The significance of this study lies in mapping, in concrete molecular detail, how cells sense amino acids and use that information to activate their growth switch. In particular, the study revealed that, upon receiving nutrient signals, the MSC—a complex involved in protein synthesis—releases its constituent protein LARS1, which then activates cellular growth signaling.
Some existing anticancer drugs work by directly inhibiting mTORC1, the cell's growth switch. However, because mTORC1 is also required for normal cellular growth and metabolism, its direct inhibition may also affect normal cells.
The research team expects that further identifying the kinase responsible for phosphorylating LARS1, along with its regulatory mechanism, could enable a more precise anticancer strategy—one that intercepts the growth signal further upstream, before it reaches mTORC1, rather than blocking mTORC1 itself.
The study was co-first-authored by Youjin Kim and Joo-Chan Kim from KAIST's Department of Chemistry and was published online in Nature Communications on June 11.
Paper title: Cryo-EM structure of the LARS1:IARS1 complex reveals a nutrient-responsive switch controlling mTORC1 signaling
DOI: https://doi.org/10.1038/s41467-026-74085-x
This work was supported by the National Research Foundation of Korea (grant nos. RS-2026-25482352 to H.S.P., RS-2024-00344154 to J.Y.K., and NRF-2021R1A3B1076605 to S.K.) and PNCC (grant no. 160183).
2026.07.27 View 739 -
KAIST Develops a Molecular Platform for the Selective Control of Oxygen Reaction Pathways
Controlling how oxygen reacts is important for improving technologies such as batteries, fuel cells, and environmentally sustainable chemical processes. A KAIST research team has developed a new molecular system that can selectively switch the pathway through which electrons are transferred during oxygen activation. The findings are expected to provide a fundamental design principle for next-generation catalysts and energy-conversion technologies.
KAIST (President Choongsik Bae) announced on the 22nd of July that a research team led by Professor Seung Jun Hwang from the Department of Chemistry has developed a molecular system capable of directing oxygen activation along a selected electron-transfer pathway. By combining germanium with a molecular framework that can store and transfer electrons, the team established a design principle for selectively switching oxygen activation between two- and four-electron pathways.
Catalysts for controlling oxygen reactions have traditionally been developed around transition-metal centers such as iron, cobalt, and nickel. Germanium, by contrast, is a main-group element in the same group of the periodic table as silicon and has generally been considered less suitable for reactions requiring the coordinated transfer of several electrons.
To overcome this limitation, the research team combined germanium with a redox-active ligand, a molecular framework capable of storing, accepting, and transferring electrons. The ligand serves as an electron reservoir and cooperates with the germanium center, allowing the entire molecular structure to participate in multielectron reactions.
When oxygen reacts, the products and reaction outcomes depend on whether two or four electrons are transferred. In general, two-electron oxygen reduction produces hydrogen peroxide, while four-electron reduction produces water. Selectively controlling these pathways is therefore an important challenge in the development of batteries, fuel cells, and greener chemical catalysts.
The study presents a rare example of a main-group molecular system in which two- and four-electron reactivity can be selectively accessed within the same underlying molecular framework. This approach broadens the range of elements that may be considered in catalyst design and provides an alternative strategy to relying exclusively on transition metals.
The team also succeeded in isolating and analyzing a germanium compound representing the two-electron stage of the reaction, which they stabilized by attaching a methyl group to the germanium complex. Remarkably, the germanium atom in this compound could both donate and accept electrons, providing an important clue to how the system controls different reaction pathways.
The team also confirmed the practical potential of the new system. Under mild, light-free conditions, the germanium complex removed halogen atoms such as bromine and chlorine from organic compounds and regenerated alkenes (organic compounds containing a carbon-carbon double bond), which are widely used as raw materials for pharmaceuticals, plastics, and other chemical products. These results suggest that useful chemical feedstocks could be produced through simpler and potentially more energy-efficient processes.
“We expect these findings to inform the development of next-generation catalysts for energy conversion and to contribute to more selective and efficient chemical processes.” said Professor Hwang.
The study was conducted by Sung Gyu Kim and Jinrok Oh, currently postdoctoral researchers in the KAIST Department of Chemistry, and Dae Eui Choi, a student in the combined master’s and doctoral program in the Department of Chemistry at POSTECH. The results were published online in the international journal Chem on July 6.
Paper title: Germanium Ligand Redox Cooperativity: A Key to Ambiphilicity and Switchable Two- and Four-Electron Transfer
DOI: 10.1016/j.chempr.2026.103127
This work was supported by National Research Foundation of Korea grants funded by the Korean government through the Ministry of Science and ICT (NRF-2021R1C1C1010220 and RS-2025-02216980), and by the Samsung Science and Technology Foundation under Project No. SSTF-BA2101-09. Sung Gyu Kim received research fellowship support from the Basic Science Research Program through the National Research Foundation of Korea, funded by the Ministry of Education (RS-2024-00415390).
2026.07.22 View 683 -
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.
2026.07.03 View 1468 -
KAIST Develops Hydrogel Material with Improved Skin Adhesion and Controllable Degradation Rate
<(From Left) Researcher Han-Yeol Yang, Professor Haeshin Lee>
Could wound healing dressings adhere better, and drug delivery patches become more sophisticated? A KAIST research team has developed a technology that leverages natural ingredients derived from plants to increase the strength of seaweed-based hydrogel (a gel material that contains a large amount of water while maintaining its shape) by more than fivefold, while also controlling its adhesiveness and degradation rate.
KAIST announced on June 9th that a research team led by Professor Haeshin Lee from the Department of Chemistry has developed a new material design strategy that utilizes tannic acid—a type of polyphenol, which is a natural antioxidant abundant in tea and fruits—to enhance the mechanical strength and adhesiveness of seaweed-derived hydrogel and to control its degradation rate.
Hydrogel is a high-moisture gel material used in contact lenses, acne patches, mask packs, and wound healing dressings. Because it can adhere closely to the skin while holding drugs or active ingredients, it is being utilized in various bio and healthcare fields, such as drug delivery systems (materials that effectively deliver drugs to desired sites), wound dressings (medical dressings that protect wounds and aid healing), tissue engineering scaffolds (structures that help regenerate artificial tissue), and cosmetic materials.
Among various hydrogel materials, the research team focused on 'κ-Carrageenan'. κ-Carrageenan is a natural polymer extracted from red seaweed (rhodophytes) such as agar-agar, and it is a familiar food ingredient used to increase the viscosity and maintain the shape of jellies and sauces. However, there were limitations to improving the performance of hydrogels made with κ-Carrageenan. The κ-Carrageenan molecule contains many structures called sulfate groups, which create intermolecular repulsion—much like magnets of the same pole pushing each other away—and prevent the formation of a dense structure. For this reason, it was difficult to increase the strength and adhesiveness of the hydrogel or to adjust the degradation rate to a desired level.
To solve this problem, the research team focused on finding a natural substance that could effectively interact with the sulfate groups. As a result, they determined that tannic acid, a natural polyphenol abundant in tea and fruits, could be a promising candidate.
Polyphenols are natural ingredients produced by plants to protect themselves from external environments such as ultraviolet rays or pests, and they have the characteristic of being able to bind with multiple substances simultaneously. In particular, tannic acid has multiple binding sites (galloyl groups), so it was expected to interact strongly with the sulfate groups of κ-Carrageenan and connect the molecules together. The research team believed that this characteristic could be utilized to reinforce the hydrogel structure.
As a result of the study, it was confirmed that the sulfate group, which was previously considered a factor hindering hydrogel formation, actually acts as a core binding site with tannic acid. In other words, the structure that was previously considered a "weakness" played a role in making the hydrogel even firmer upon meeting tannic acid.
< Research Image Related to Polyphenol Interactions >
In fact, the storage modulus (an index representing the firmness and elasticity of a gel) of the κ-Carrageenan hydrogel with added tannic acid was approximately 1,632 Pa, showing an improvement of more than fivefold compared to the pure κ-Carrageenan hydrogel (approximately 294 Pa). This means that the hydrogel can maintain its shape more stably even under external pressure or deformation, demonstrating that it can increase the durability and usability of wound healing dressings or drug delivery patches.
In addition, the research team confirmed that tannic acid stably reinforces the internal network structure (gel network) of the already formed hydrogel, regardless of the point in time when the tannic acid is added. This implies that tannic acid connects molecules at multiple points, allowing the internal structure of the hydrogel to remain consistently firm.
Notably, the research team succeeded in implementing rapid degradability and strong adhesiveness simultaneously. In experiments simulating the human stomach and intestinal environments, the hydrogel containing tannic acid degraded relatively quickly while adhering strongly to the skin and rough surfaces. This means that wound healing dressings will not easily fall off during use but can naturally degrade after completing their role, and drug delivery patches can be utilized to stably deliver drugs for a desired period.
This study is meaningful in that it presented a design principle capable of simultaneously controlling the strength, adhesiveness, and degradation rate of hydrogel using only food-grade natural ingredients without complex chemical synthesis processes. The research team expects this technology to be utilized in various bio and healthcare fields, such as capsules and coating materials for food and functional foods, skin-adhering cosmetics and skincare products, wound dressings, drug delivery patches, and tissue engineering scaffolds.
<Research Image (AI-Generated)>
Professor Haeshin Lee said, "This study is an example showing that the mechanical strength, adhesiveness, and degradation behavior of hydrogel can be designed together using only naturally derived materials," adding, "It can be expanded into a safer and simpler natural polymer gel platform in the fields of food, cosmetics, and biomaterials."
This study, in which PhD student Han-Yeol Yang participated as the first author, was published on April 21st in 'Biomimetics', an international academic journal in the field of biomimetics. ※ Paper Title: Adhesive κ-Carrageenan Hydrogels by Polyphenol Intervention, DOI: 10.3390/biomimetics11040290
Meanwhile, this research was conducted with research funding support from Polyphenol Factory Inc., a faculty-led startup enterprise of KAIST.
2026.06.09 View 1965 -
KAIST Produces Eco-Friendly Core Nylon Precursors Used from Clothing to Automobiles with Microbes
<(From Left) Dr. Da-Hee Ahn, Distinguished Professor Sang Yup Lee>
Nylon is a representative plastic material used throughout our daily lives, from clothing to automobiles. However, most of its raw materials have been produced through petrochemical processes, resulting in large carbon emissions. KAIST researchers have developed a technology that can produce key nylon precursors in an eco-friendly way using microbes.
KAIST (President Kwang Hyung Lee) announced on the 31st of May that a research team led by Distinguished Professor Sang Yup Lee of the Department of Chemical and Biomolecular Engineering has developed an Escherichia coli-based modular platform capable of producing three key monomers (basic molecular units that make up polymers) of “nylon 6,6” and “nylon 6” — adipic acid, hexamethylenediamine, and epsilon-caprolactam — from “glycerol (an eco-friendly bio-based byproduct generated during biodiesel production),” a renewable carbon source, using systems metabolic engineering (a technology that designs and optimizes microbial metabolic pathways to maximize the production of desired substances).
“Nylon 6” is highly flexible and is used in clothing and films, while “nylon 6,6” has excellent strength and heat resistance and is used in automobiles and machinery parts. The numbers after the nylon name indicate the number of carbon atoms contained in the raw material molecules.
The core of this study is that the biosynthetic pathway was divided into upstream and downstream modules, with E. coli strains assigned different roles. The upstream strain was designed to produce adipic acid from glycerol, while the downstream strain was designed to convert it into hexamethylenediamine or epsilon-caprolactam, respectively. Through this, the research team succeeded in producing adipic acid and hexamethylenediamine, the key raw materials of nylon 6,6, and epsilon-caprolactam, the key raw material of nylon 6, within a single integrated platform.
To improve production efficiency, the researchers compared and validated various enzymes (proteins that promote chemical reactions in living organisms), including carboxylic acid reductases and transaminases, and applied the optimal combination, thereby improving hexamethylenediamine titer. In addition, in the epsilon-caprolactam production process, they designed a flexible-linker fusion enzyme that enhances reaction efficiency through efficient cofactor regeneration.In the upstream module, the team reconstructed the biosynthetic pathway (a series of reaction processes through which compounds are produced in living organisms) and improved the performance of key enzymes using artificial intelligence (AI), increasing production titer. As a result, they succeeded in producing adipic acid at a level of 6 grams per liter (g/L) in a fed-batch fermentation process.
The research team also applied a “delayed inoculation” strategy (time-staggered co-culture), in which the second strain is introduced later after sufficient adipic acid has first been produced, rather than adding the two types of E. coli simultaneously. This is a method of sequentially introducing microbes with different roles at different times.
When this strategy was applied to a fed-batch fermentation process (a fermentation method that increases productivity by supplying nutrients step by step), the team produced 230 milligrams per liter (mg/L) of hexamethylenediamine and 808 micrograms per liter (μg/L) of epsilon-caprolactam using only glycerol. Although the production amounts are not yet high, the research team explained that these results represent world-class performance among cases of direct production from glycerol.
<Schematic Diagram>
This technology is significant in that it presents the possibility of producing nylon raw materials, which have relied on petrochemical processes, through bio-based methods.
The research team plans to further improve titer by combining AI-based enzyme design with additional systems metabolic engineering, and to expand the platform to produce various polymer raw materials (substances formed by the repeated bonding of multiple monomers).
Distinguished Professor Sang Yup Lee stated, “This study is meaningful in that it presents a modular microbial platform capable of producing key monomers required for nylon 6 and nylon 6,6 production from renewable carbon sources,” adding, “We will continue to advance enzyme and metabolic flux engineering to improve titer and develop this into a core platform for sustainably producing various bio-based polymer raw materials.”
The results of this study were published on May 4 in the Proceedings of the National Academy of Sciences (PNAS), with Dr. Da-Hee Ahn of the Department of Chemical and Biomolecular Engineering as the first author.
※ Paper title: “Metabolic engineering of Escherichia coli for the biosynthesis of nylon 6 and nylon 6,6 monomers”
Authors: Sang Yup Lee (KAIST, corresponding author), Da-Hee Ahn (KAIST, first author), Tong Un Chae (KAIST, second author), total of 3 authors
DOI: https://doi.org/10.1073/pnas.2535786123
This research was supported by the “Development of Platform Technologies of Microbial Cell Factories for the Next-Generation Biorefineries” project under the Petroleum Replacement Eco-Friendly Chemical Technology Development Program supported by the Ministry of Science and ICT, and by the “Development of Advanced Synthetic Biology Source Technologies for Leading the Biomanufacturing Industry” project under the Core Synthetic Biology Technology Development Program.
2026.06.01 View 1489 -
KAIST, Making Pharmaceuticals with Light and Air… Solving a Long-Standing Challenge in Chemical Synthesis
<(From Left) Professor Sang Woo Han, Researcher Jin Wook Baek>
In chemical processes for producing pharmaceuticals, catalysts are the key to determine production speed and cost. However, until now, there has been a trade-off between “precise but disposable catalysts” and “reusable catalysts.” A KAIST research team has developed an eco-friendly catalytic technology that combines these two types, operating with light and air. This opens a pathway to producing pharmaceutical ingredients more cheaply and cleanly, with expected reductions in carbon emissions and environmental pollution.
KAIST (President Kwang Hyung Lee) announced on the 30th of March that a research team led by Professor Sang Woo Han of the Department of Chemistry has succeeded in combining two different types of catalysts into one system. One is a silver (Ag)-based catalyst that operates in a solid state, and the other is an organic photocatalyst, DDQ (a substance that triggers chemical reactions upon absorbing light), which operates in solution. By enabling these two catalysts to function together, the team made it possible to carry out previously difficult reactions more efficiently.
< Schematic diagram of the operation of a heterogeneous–homogeneous hybrid photocatalytic system >
Using this technology, the researchers successfully produced amines—key raw materials for pharmaceuticals—through an environmentally friendly process using light and air. This demonstrated that the desired substances can be synthesized without additional chemical reagents, proving the practicality of the technology.
Conventional organic photocatalysis required additional chemicals to reuse catalysts after reactions, or suffered from reduced efficiency due to slow reaction rates when using oxygen from air.
To address this, the research team proposed a method of reusing byproducts generated during the reaction. These byproducts restore the catalyst to a reusable state, while oxygen in the air helps sustain this cycle. In other words, instead of being used once and discarded, the catalyst regenerates itself and continues operating in a “cyclic system.”
As a result, they established a “cyclic catalytic system” that continues functioning without the need for additional chemical inputs. Notably, this system operates with light and air. Light activates the catalyst to initiate the reaction, while air restores the used catalyst to its active state. In essence, the catalyst continuously “recharges” and operates repeatedly. Since air leaves only water as a byproduct in this process, the environmental burden is significantly reduced.
In addition, to solve the issue of reduced performance when different catalysts interact, the team introduced lithium salt (LiClO₄). This substance helps regulate interactions between the two catalysts, significantly improving their stability and lifespan.
< A hybrid catalyst powered by light and air as energy sources >
Professor Sang Woo Han stated, “This research is the first to successfully integrate an inorganic photochemical loop system—where a metal-based catalyst reacts under light and returns to its original state—into the field of organic synthesis,” adding, “It represents an important advancement that combines the advantages of different catalytic systems to dramatically reduce the carbon footprint of the chemical industry.” He further noted, “It opens a new pathway for producing high-value compounds, such as pharmaceutical ingredients, in the most environmentally friendly way.”
This research was conducted with Jin Wook Baek of the KAIST Department of Chemistry as the first author, and the results were published on March 18 in the Journal of the American Chemical Society (JACS), a leading journal in chemistry.
※ Paper title: “Merger of heterogeneous and homogeneous photocatalysis for arene C–H Amination”
※ DOI: 10.1021/jacs.5c20824
This research was supported by the National Research Foundation of Korea’s Mid-career Researcher Program.
2026.03.30 View 1651 -
Professor Jihyeon Yeom Selected as Early Career Advisory Board Member for Top Chemistry and Materials Journal
< Professor Jihyeon Yeom >
KAIST announced on the 13th that Professor Jihyeon Yeom from the Department of Materials Science and Engineering has been selected as a member of the Early Career Advisory Board (ECAB) for Chemical Reviews, widely considered the world's most prestigious academic journal in the field of chemistry.
Published by the American Chemical Society (ACS), Chemical Reviews is a flagship review journal that comprehensively organizes and surveys the most influential research achievements across all areas of chemistry and materials science. It is evaluated as a top-tier international journal in the field.
The journal boasts an Impact Factor (IF) of 56, ranking it among the highest of all scientific journals worldwide. Its authority is particularly significant because it is a review journal that analyzes global research trends to suggest future academic directions, rather than simply publishing individual experimental data.
The ECAB, which began its term in January 2026, consists of 10 researchers selected from among rising global science leaders. Candidates are evaluated based on academic originality, research impact, and contributions to the scientific community. Members provide advisory roles for the journal's academic direction and strategic planning, contributing to the discovery of next-generation research trends and the expansion of global research networks.
This selection highlights that Professor Yeom’s research achievements are receiving high international acclaim.
Professor Yeom is conducting research on applying "chirality"—a property where objects, like DNA or proteins, are mirror images of each other but cannot be perfectly superimposed—to nanomaterials. Her core work involves precisely controlling atomic arrangements to realize artificial materials that can interact naturally with biological signals.
In particular, she is gaining attention for developing next-generation smart healthcare technology that combines light-responsive chiral materials with Artificial Intelligence (AI) to detect and analyze minute changes in the human body in real time. Professor Yeom explained that these chiral characteristics offer new possibilities for expanding information transmission and processing capabilities beyond simple structural properties.
Building on this foundation, she plans to expand her research into various fields, including precision medical diagnostic technology, next-generation optoelectronic devices utilizing circularly polarized light, and AI-based platforms.
Professor Yeom has established herself as a global leader in chiral materials research, recently publishing results in world-renowned journals such as Nature Communications, Advanced Materials, ACS Nano, and Accounts of Chemical Research.
"Chirality is not just a structural characteristic, but a new degree of freedom that expands the functional and information-processing capabilities of matter," said Professor Yeom. "I plan to expand my research into chiral-based electronic and optical devices, bio-diagnostic technologies, and AI-based spectroscopic platforms in the future."
This ECAB selection once again demonstrates the research competitiveness and international standing of the KAIST Department of Materials Science and Engineering. It is expected to further strengthen KAIST's role as a global research hub in the field of next-generation materials research.
2026.03.13 View 2246 -
KAIST Develops Self-Regenerating Catalyst That Restores Its Own Performance, Opening a Breakthrough for CO₂ Conversion Technology
<(From Left) Professor Dong Young Chung, Ph.D Candidate Hongmin An, Hanjoo Kim>
Technologies that convert carbon dioxide (CO₂) emitted from factories and power plants into useful chemical feedstocks are considered key to achieving carbon neutrality. However, rapid degradation of catalyst performance has long hindered commercialization. KAIST researchers have now developed a “self-regenerating” catalyst that restores its activity during operation, offering a potential solution to this challenge.
KAIST (President Kwang Hyung Lee) announced on the 11th of March that a research team led by Professor Dong Young Chung from the Department of Chemical and Biomolecular Engineering has identified the fundamental cause of catalyst degradation in electrochemical reactions that convert CO₂ into useful materials and has developed a new design strategy that allows catalysts to maintain their active state during the reaction.
<Schematic Illustration of Copper Catalyst Reconstruction>
The research team focused particularly on copper (Cu) catalysts, which are widely used in CO₂ conversion reactions. Copper catalysts are known not to simply degrade during reactions but instead undergo a process called surface reconstruction, in which their surface structure continuously changes. The study revealed that the performance and lifetime of the catalyst vary significantly depending on how this reconstruction occurs.
The researchers discovered that copper catalyst reconstruction occurs mainly through two different mechanisms. The first involves formation and reduction of oxide layers on the catalyst surface. While this temporarily increases catalytic activity, it ultimately leads to long-term degradation of catalyst performance.
The second mechanism involves partial dissolution of the catalyst metal into the electrolyte followed by redeposition onto the catalyst surface. During this process, new reactive sites—known as active sites—are continuously created on the catalyst surface.
Based on this mechanism, the team proposed a method that allows the catalyst to maintain its active state during the reaction. By introducing a trace amount of copper ions into the electrolyte, dissolution and redeposition of copper occur in a balanced cycle on the catalyst surface. This continuous cycle generates new active sites, enabling the catalyst to maintain stable performance over extended periods.
Importantly, this technology can be implemented without complex additional processes or high-voltage conditions, significantly reducing energy consumption while enabling stable production of high-value C₂ compounds such as ethylene and ethanol. C₂ compounds are molecules containing two carbon atoms and are industrially important chemicals used as feedstocks for plastics, fuels, and other materials.
This research is significant because it proposes a new design concept in which catalysts are not merely optimized at the initial stage but are engineered to maintain their optimal state throughout the reaction process. The concept is expected to be applicable not only to CO₂ conversion technologies but also to a wide range of electrochemical energy conversion systems.
Professor Dong Young Chung stated, “This research approached catalyst degradation not as an inevitable phenomenon but as a controllable process,” adding, “We proposed a new strategy that allows catalysts to continuously maintain optimal activity during the reaction.”
The study was led by Hanjoo Kim, a doctoral student at KAIST, and Hongmin An, a combined master’s-doctoral student, as co-first authors. The research was published online on February 5 in the Journal of the American Chemical Society (JACS), one of the world’s most prestigious journals in chemistry.
※ Paper title: “Dynamic Interface Engineering via Mechanistic Understanding of Copper Reconstruction in Electrochemical CO₂ Reduction Reaction” DOI: 10.1021/jacs.5c16244
This research was supported by the Global Young Connect Program for Materials and the National Strategic Materials Technology Development Program funded through the National Research Foundation of Korea.
2026.03.11 View 2497 -
AI that Understands Chemical Principles... Accelerating the Development of New Drugs and Materials
<(From top left) Professor Woo Youn Kim (KAIST), Dr. Jeheon Woo (KISTI), Dr. Seonghwan Kim (KAIST), and Jun Hyeong Kim (PhD candidate)>
Whether a smartphone battery lasts longer or a new drug can be developed to treat incurable diseases depends on how stably the atoms constituting the material are bonded. The core of 'molecular design' lies in finding how to arrange these countless atoms to form the most stable molecule. Until now, this process has been as difficult as finding the lowest valley in a massive mountain range, requiring immense time and costs. Researchers at KAIST have developed a new technology that uses artificial intelligence to solve this process quickly and accurately.
KAIST announced on February 10th that Professor Woo Youn Kim's research team in the Department of Chemistry has developed 'Riemannian DenoisingModel (R-DM),' an artificial intelligence model that understands the physical laws governing molecular stability to predict structures.
The most significant feature of this model is that it directly considers the 'energy' of the molecule. While existing AI models simply mimicked the shape of molecules, R-DM refines the structure by considering the forces acting within the molecule. The research team represented the molecular structure as a map where higher energy is depicted as hills and lower energy as valleys, designing the AI to move toward and find the valleys with the lowest energy.
R-DM completes the molecule by navigating this energy landscape, avoiding unstable structures to find the most stable state. This applies the mathematical theory of 'Riemannian geometry,' resulting in the AI learning the fundamental law of chemistry: 'matter prefers the state with the lowest energy.'
Experimental results showed that R-DM achieved up to 20 times higher accuracy than existing AI models, reducing prediction errors to a level nearly indistinguishable from precise quantum mechanical calculations. This represents the world's highest level of performance among AI-based molecular structure prediction technologies.
<Comparison of energy landscapes in Euclidean space and Riemannian space>
This technology can be utilized in various fields, including new drug development, next-generation battery materials, and high-performance catalyst design. It is expected to serve as an 'AI simulator' that will dramatically speed up research and development by significantly shortening the molecular design process, which previously took a long time. Furthermore, it has great potential in environmental and safety fields, as it can quickly predict chemical reaction paths in situations where experiments are difficult, such as chemical accidents or the spread of hazardous substances.
Professor Woo Youn Kim stated, "This is the first case where artificial intelligence has understood the basic principles of chemistry and judged molecular stability on its own. It is a technology that can fundamentally change the way new materials are developed."
<Image of Riemannian Diffusion Model application (AI-generated image)>
This study was led by Dr. Jeheon Woo from the KISTI Supercomputing Center and Dr. Seonghwan Kim from the KAIST Innovative Drug Discovery Research Group as co-first authors. The research results were published on January 2nd in the world-renowned academic journal Nature Computational Science.
※ Paper Title: Riemannian Denoising Model for Molecular Structure Optimization with Chemical Accuracy, DOI: 10.1038/s43588-025-00919-1
Meanwhile, this research was conducted with the support of the Chemical Accident Prediction-Prevention Advanced Technology Development Project of the Korea Environmental Industry & Technology Institute, the Science and Technology Institute InnoCore Project of the Ministry of Science and ICT, and the Data Science Convergence Talent Cultivation Project conducted by the National Research Foundation of Korea with support from the Ministry of Science and ICT.
2026.02.10 View 3469 -
KAIST Proposes a New Dementia Treatment Strategy by Repositioning Molecules without Changing Their Chemical Composition
<(Back row, from left) Professor Mi Hee Lim, Professor Mingeun Kim, Student Jimin Lee, Student Chanju Na, (Upper Right) Dr. Chul-Ho Lee, Dr Kyoung-Shim Kim>
Conventional treatments of Alzheimer’s disease, one of the most common forms of dementia, have been largely focused on targeting individual pathological features. However, Alzheimer’s disease is a multifactorial disorder driven by multiple, tightly interconnected processes, rendering single-target therapeutic approaches inherently limited. Addressing this challenge, KAIST researchers propose a new strategy that enables the simultaneous regulation of multiple disease-inducing factors simply by rearranging the structural positions of drug candidate molecules without altering their chemical substituents.
KAIST (President Kwang Hyung Lee) announced on January 22 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 of the Korea Research Institute of Bioscience and Biotechnology (KRIBB), and Dr. Kyoung-Shim Kim of the Laboratory Animal Resource Center, has elucidated at the molecular level how subtle differences in molecular arrangement, specifically positional isomerism, give rise to distinct modes of action against Alzheimer’s disease.
Using an Alzheimer’s disease mouse model (APP/PS1) harboring human dementia-associated genes, the research team demonstrated that these compounds also exert distinct therapeutic effects in vivo.
Alzheimer’s disease does not arise from a single cause. Rather, multiple pathological factors, including amyloid-b, metal ions, and reactive oxygen species, interact synergistically to exacerbate disease progression. In particular, metal ions bind to amyloid-b, modulating its aggregation and toxicity while promoting the generation of reactive oxygen species, which in turn accelerates neuronal damage. Effective control of Alzheimer’s disease therefore requires therapeutic strategies capable of simultaneously targeting multiple interrelated pathological processes.
< Alzheimer’s Disease – Chemical Approach Illustration (AI-generated image) >
The researchers focused on positional isomers, molecules composed of the same chemical elements but differing only in the positions at which those elements are connected. Remarkably, simple changes in molecular positioning resulted in pronounced differences in reactivity towards reactive oxygen species, as well as in interactions with amyloid-b and metal-bound amyloid-b.
To investigate these effects, the team compared the reactivities of three structurally similar molecules differing only in the positions of their functional groups. Their analyses revealed that even minimal structural rearrangements led to significant differences in antioxidant capacity and produced distinct modes of modulation of amyloid-b and metal-bound amyloid-b through different mechanisms, inducing peptide chemical modifications.
In other words, the study demonstrated that Alzheimer’s disease-related pathological factors can be regulated through mechanistically distinct pathways simply by altering molecular arrangement, without changing molecular composition.
Notably, a specific positional isomer capable of simultaneously modulating reactive oxygen species, amyloid-b, and metal-bound amyloid-b complexes also demonstrated therapeutic efficacy in an Alzheimer’s disease mouse model. In these experiments, the compound reduced oxidative stress in the hippocampus, the brain region critical for memory, and decreased amyloid plaque accumulation, resulting in significant improvements in memory deficits and cognitive impairment.
< In Vivo Efficacy Evaluation and Biological Outcomes According to Positional Isomers of Small-Molecule Compounds >
Professor Mi Hee Lim of KAIST stated, “This study demonstrates that multiple pathological factors associated with Alzheimer’s disease can be targeted simultaneously simply by adjusting molecular positioning, without altering the molecule’s core chemical framework.” She added, “These findings point to a new therapeutic strategy that may enable more precise control of complex, multifactorial diseases such as Alzheimer’s disease.”
This research was conducted with Chanju Na and Jimin Lee, integrated master’s-doctoral students in the Department of Chemistry at KAIST, who served as co-first authors. The results were published in the Journal of the American Chemical Society (Impact Factor: 15.7, top 5.0% in Chemistry) in Issue 1 dated January 14, 2026.
※ Paper title: “Positional Isomerism Tunes Molecular Reactivities and Mechanisms toward Pathological Targets in Dementia”
※ DOI: 10.1021/jacs.5c14323
This study was supported by the National Research Foundation (NRF) of Korea through the Basic Research Program (Creative Research Initiative and Global Science Research Center), the NRF Sejong Science Fellowship, the NRF Ph.D. Followship, and KRIBB Institutional Funding.
2026.01.26 View 2378 -
KAIST Unveils Cause of Performance Degradation in Electric Vehicle High-Nickel Batteries: "Added with Good Intentions
<(From left in the front row) Professor Nam-Soon Choi, Professor Dong-Hwa Seo, (back row, from left) Ph.D candidate Gihoon Lee, Ph.D candidate Seung Hee Han, Ph.D candidate Jae-Seung Kim, (top) M.S candidate Junyoung Kim>
High-nickel batteries, which are high-energy lithium-ion batteries primarily used in electric vehicles, offer high energy density but suffer from rapid performance degradation. A research team from KAIST has, for the first time globally, identified the fundamental cause of the rapid deterioration (degradation) of high-nickel batteries and proposed a new approach to solve it.
KAIST announced on December 3rd that a research team led by Professor Nam-Soon Choi of the Department of Chemical and Biomolecular Engineering, in collaboration with a research team led by Professor Dong-Hwa Seo of the Department of Materials Science and Engineering, has revealed that the electrolyte additive 'succinonitrile (CN4), which has been used to improve battery stability and lifespan, is actually the key culprit causing performance degradation in high-nickel batteries.
In a battery, electricity is generated as lithium ions travel between the cathode and the anode. A small amount of CN4 is included in the electrolyte to facilitate the movement of lithium. The research team confirmed through computer calculations that CN4, which has two nitrile (-CN) structures, attaches excessively strongly to the nickel ions on the surface of the high-nickel cathode.
The nitrile structure is a 'hook-like' structure, where carbon and nitrogen are bound by a triple bond, making it adhere well to metal ions. This strong bonding destroys the protective electrical double layer (EDL) that should form on the cathode surface. During the charging and discharging process, the cathode structure is distorted (Jahn-Teller distortion), and even electrons from the cathode are drawn out to the CN4, leading to rapid damage of the cathode.
Nickel ions that leak out during this process migrate through the electrolyte to the anode surface, where they accumulate. This nickel acts as a 'bad catalyst' that accelerates electrolyte decomposition and wastes lithium, further speeding up battery degradation.
Various analyses confirmed that CN4 transforms the high-nickel cathode surface into an abnormal layer deficient in nickel, and changes the normally stable structure into an abnormal 'rock-salt structure'.
This proves the dual nature of CN4: while useful in LCO batteries (lithium cobalt oxide), it actually causes the structural collapse in high-nickel batteries with a high nickel ratio.
This research holds significant meaning as a precise analysis that goes beyond simple control of charging/discharging conditions, to even elucidating the actual electron transfer occurring between metal ions and electrolyte molecules. Based on this achievement, the research team plans to develop a new electrolyte additive optimized for high-nickel cathodes.
<Schematic diagram of the ligand coordination between CN₄ molecules and Ni³⁺ on the high-nickel cathode surface and the cathode structural degradation process>
Professor Nam-Soon Choi stated, "A precise, molecular-level understanding is essential to enhance battery lifespan and stability. This research will pave the way for the development of new additives that do not excessively bond with nickel, significantly contributing to the commercialization of next-generation high-capacity batteries."
This research, jointly led by Professor Nam-Soon Choi, Seung Hee Han, Junyoung Kim, and Gihoon Lee of the Department of Chemical and Biomolecular Engineering, and Professor Dong-Hwa Seo and Jae-Seung Kim of the Department of Materials Science and Engineering as co-first authors, was published online on November 14th in the prestigious international journal 'ACS Energy Letters' and was selected as the cover article.
※ Paper Title: Unveiling Bidentate Nitrile-Driven Structural Degradation in Ultra-High-Nickel Cathodes,
https://doi.org/10.1021/acsenergylett.5c02845
<Cover Page of International Journal(ACS Energy Letters)>
The research was supported by Samsung SDI.
2025.12.03 View 3905