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KAIST achieves quantum entanglement essential for quantum error correction
Quantum computing is a technology capable of solving complex problems that classical computers struggle with. To perform accurate computations, quantum computers must correct errors that arise during operations. However, generating the quantum entanglement necessary for quantum error correction has long been considered a major challenge.
< Photo 1. (From left) Students Young-Do Yoon and Chan Roh of the Master's and Doctoral Integrated Program of the Department of Physics poses with Professor Young-Sik Ra and Student Geunhee Gwak of the same program >
KAIST (represented by President Kwang Hyung Lee) announced on the 25th of February that a research team led by Professor Young-Sik Ra from the Department of Physics has successfully implemented a three-dimensional cluster quantum entangled state, a key component for quantum error correction, through experimental demonstration.
Measurement-based quantum computing is an emerging paradigm that implements quantum computations by measuring specially entangled cluster states. The core of this approach lies in the generation of these cluster quantum entangled states, with two-dimensional cluster states commonly used for universal quantum computing.
However, to advance towards fault-tolerant quantum computing, which can correct quantum errors occurring during computations, a more complex three-dimensional cluster state is required. While previous studies have reported the generation of two-dimensional cluster states, experimental implementation of the three-dimensional cluster states necessary for fault-tolerant quantum computing had remained elusive due to the extreme complexity of their entanglement structure.
< Figure 1. (a) Experimental schematic. A pulse laser with a wavelength of 800 nm is converted into a pulse laser with a wavelength of 400 nm through second harmonic generation, and this is incident on a nonlinear crystal (PPKTP) to generate multiple quantum entanglement sources. (b) Generation of a 3D cluster state through optical mode basis change >
The research team overcame this challenge by developing a technique to control femtosecond time-frequency modes, successfully generating a three-dimensional cluster quantum entangled state for the first time.
The team directed a femtosecond laser into a nonlinear crystal, simultaneously generating quantum light sources across multiple frequency modes. (A femtosecond laser is a device that emits ultrashort, high-intensity light pulses.) Using this approach, they successfully created a three-dimensional cluster quantum entangled state.
Professor Young-Sik Ra noted, “This study marks the first successful demonstration of a three-dimensional cluster quantum entangled state, which was previously difficult to achieve with existing technology. This breakthrough is expected to serve as a crucial stepping stone for future research in measurement-based and fault-tolerant quantum computing.”
< Figure 2. Results of 3D cluster state generation. (a) Nullifier measurement of the cluster state. (b) 3D cluster state reconstructed using quantum state tomography. (c) Confirmation of quantum entanglement characteristics of the 3D cluster state >
The study was published online in Nature Photonics on February 24, 2025. The first author is Chan Roh, a Ph.D. candidate in KAIST’s integrated master’s and doctoral program, with Geunhee Gwak and Youngdo Yoon contributing as co-authors. (Paper title: “Generation of Three-Dimensional Cluster Entangled State”, DOI: 10.1038/s41566-025-01631-2)
This research was supported by the National Research Foundation of Korea (Quantum Computing Technology Development Program, Mid-Career Researcher Support Program, and Quantum Simulator for Materials Innovation Program), the Institute for Information & Communications Technology Planning & Evaluation (Quantum Internet Core Technology Program, University ICT Research Center Support Program), and the U.S. Air Force Research Laboratory.
2025.02.25 View 500 -
KAIST develops ‘Hoverbike’ to roam the future skies
< Photo 1. A group photo of the research team >
Hoverbike is a kind of next-generation mobility that can complement the existing transportation system and can be used as an air transportation means without traffic congestion through high-weight payloads and long-distance flights. It is expected that domestic researchers will contribute to the development of the domestic PAV* and UAM markets by developing a domestically developed manned/unmanned hybrid aircraft that escapes dependence on foreign technology through the development of a high-performance hoverbike.
*PAV: Personal Aerial Vehicle. It is a key element of future urban air mobility (UAM, Urban Air Mobility) and constitutes an important part of the next-generation transportation system.
KAIST (President Kwang-Hyung Lee) announced on the 27th of December that the research team of Professor Hyochoong Bang of the Department of Aerospace Engineering successfully developed the core technology of a highly reliable multipurpose vertical takeoff and landing hoverbike that can be operated by both manned and unmanned vehicles.
This research was participated by the research teams of Professor Jae-Hung Han, Professor Ji-yun Lee, Professor Jae-myung Ahn, Professor Han-Lim Choi, and Professor Chang-Hun Lee of the Department of Aerospace Engineering at KAIST, Professor Dongjin Lee of the Department of Unmanned Aerial Vehicles at Hanseo University, and Professor Jong-Oh Park of the Department of Electronics Engineering at Dong-A University.
The research team secured key technologies related to the optimal design of a multipurpose aircraft, hybrid propulsion system, highly reliable precision navigation and flight control system, autonomous flight, and fault detection for the development of a high-performance hoverbike.
< Figure 1. Key features of high-reliability multi-purpose hoverbike >
The hoverbike platform introduced a gasoline engine-based hybrid system to overcome the shortcomings of battery-based drones, achieving approximately 60% better performance and maximum payload weight compared to overseas technology levels. Through this, it is expected to be utilized in various fields such as emergency supply delivery, logistics, and rescue activities for civilian use, and military transport and mission support for military use.
The navigation system was applied by implementing multi-sensor fusion technology based on DGPS/INS* to enable stable flight even in environments without GPS or with weak signals using high-reliability precision navigation technology.
*DGPS/INS: Navigation solution combining high accuracy of Differential GPS (DGPS) and Inertial Navigation System (INS)
In addition, high-reliability flight control technology was developed to enable reliable maneuvering even under external factors such as payload and wind, and model uncertainty, and fault detection technology was also developed.
A guidance technique to automatically land on a helipad after selecting a safe automatic landing area by configuring a high-reliability autonomous flight system was implemented with high accuracy. Stable operation is possible even in complex environments through obstacle avoidance and automatic landing autonomous flight technology.
< Figure 2. Hoverbike prototype model >
Professor Hyochoong Bang, the research director, emphasized, “We have proven the high practicality of the hoverbike in various environments through high-reliability flight control and precision navigation technology.” He added, “The hoverbike is a promising research result that can not only provide a major path leading to PAVs and future aircraft, but also surpass existing drone technology by several levels. This achievement is even more meaningful because it is the result of five years of effort by eight joint research teams, including the project’s practitioners, PhD students Kwangwoo Jang and Hyungjoo Ahn.”
This study aims to secure core technologies for manned/unmanned multipurpose hoverbikes that can be utilized as new concept aircraft in the defense and civilian sectors. It started as the Defense Acquisition Program Administration’s Defense Technology for Future Challenge Research and Development Project in 2019 and was completed in 2024 under the management of the Agency for Defense Development. It is scheduled to be exhibited for the first time at the 2025 Drone Show Korea (DSK2025), which will be held at BEXCO in Busan from February 26 to 28, 2025.
2024.12.27 View 2426 -
KAIST Proposes a New Way to Circumvent a Long-time Frustration in Neural Computing
The human brain begins learning through spontaneous random activities even before it receives sensory information from the external world. The technology developed by the KAIST research team enables much faster and more accurate learning when exposed to actual data by pre-learning random information in a brain-mimicking artificial neural network, and is expected to be a breakthrough in the development of brain-based artificial intelligence and neuromorphic computing technology in the future.
KAIST (President Kwang-Hyung Lee) announced on the 16th of December that Professor Se-Bum Paik 's research team in the Department of Brain Cognitive Sciences solved the weight transport problem*, a long-standing challenge in neural network learning, and through this, explained the principles that enable resource-efficient learning in biological brain neural networks.
*Weight transport problem: This is the biggest obstacle to the development of artificial intelligence that mimics the biological brain. It is the fundamental reason why large-scale memory and computational work are required in the learning of general artificial neural networks, unlike biological brains.
Over the past several decades, the development of artificial intelligence has been based on error backpropagation learning proposed by Geoffery Hinton, who won the Nobel Prize in Physics this year. However, error backpropagation learning was thought to be impossible in biological brains because it requires the unrealistic assumption that individual neurons must know all the connected information across multiple layers in order to calculate the error signal for learning.
< Figure 1. Illustration depicting the method of random noise training and its effects >
This difficult problem, called the weight transport problem, was raised by Francis Crick, who won the Nobel Prize in Physiology or Medicine for the discovery of the structure of DNA, after the error backpropagation learning was proposed by Hinton in 1986. Since then, it has been considered the reason why the operating principles of natural neural networks and artificial neural networks will forever be fundamentally different.
At the borderline of artificial intelligence and neuroscience, researchers including Hinton have continued to attempt to create biologically plausible models that can implement the learning principles of the brain by solving the weight transport problem.
In 2016, a joint research team from Oxford University and DeepMind in the UK first proposed the concept of error backpropagation learning being possible without weight transport, drawing attention from the academic world. However, biologically plausible error backpropagation learning without weight transport was inefficient, with slow learning speeds and low accuracy, making it difficult to apply in reality.
KAIST research team noted that the biological brain begins learning through internal spontaneous random neural activity even before experiencing external sensory experiences. To mimic this, the research team pre-trained a biologically plausible neural network without weight transport with meaningless random information (random noise).
As a result, they showed that the symmetry of the forward and backward neural cell connections of the neural network, which is an essential condition for error backpropagation learning, can be created. In other words, learning without weight transport is possible through random pre-training.
< Figure 2. Illustration depicting the meta-learning effect of random noise training >
The research team revealed that learning random information before learning actual data has the property of meta-learning, which is ‘learning how to learn.’ It was shown that neural networks that pre-learned random noise perform much faster and more accurate learning when exposed to actual data, and can achieve high learning efficiency without weight transport.
< Figure 3. Illustration depicting research on understanding the brain's operating principles through artificial neural networks >
Professor Se-Bum Paik said, “It breaks the conventional understanding of existing machine learning that only data learning is important, and provides a new perspective that focuses on the neuroscience principles of creating appropriate conditions before learning,” and added, “It is significant in that it solves important problems in artificial neural network learning through clues from developmental neuroscience, and at the same time provides insight into the brain’s learning principles through artificial neural network models.”
This study, in which Jeonghwan Cheon, a Master’s candidate of KAIST Department of Brain and Cognitive Sciences participated as the first author and Professor Sang Wan Lee of the same department as a co-author, was presented at the 38th Neural Information Processing Systems (NeurIPS), the world's top artificial intelligence conference, on December 14th in Vancouver, Canada. (Paper title: Pretraining with random noise for fast and robust learning without weight transport)
This study was conducted with the support of the National Research Foundation of Korea's Basic Research Program in Science and Engineering, the Information and Communications Technology Planning and Evaluation Institute's Talent Development Program, and the KAIST Singularity Professor Program.
2024.12.16 View 4127 -
KAIST Secures Core Technology for Ultra-High-Resolution Image Sensors
A joint research team from Korea and the United States has developed next-generation, high-resolution image sensor technology with higher power efficiency and a smaller size compared to existing sensors. Notably, they have secured foundational technology for ultra-high-resolution shortwave infrared (SWIR) image sensors, an area currently dominated by Sony, paving the way for future market entry.
KAIST (represented by President Kwang Hyung Lee) announced on the 20th of November that a research team led by Professor SangHyeon Kim from the School of Electrical Engineering, in collaboration with Inha University and Yale University in the U.S., has developed an ultra-thin broadband photodiode (PD), marking a significant breakthrough in high-performance image sensor technology.
This research drastically improves the trade-off between the absorption layer thickness and quantum efficiency found in conventional photodiode technology. Specifically, it achieved high quantum efficiency of over 70% even in an absorption layer thinner than one micrometer (μm), reducing the thickness of the absorption layer by approximately 70% compared to existing technologies.
A thinner absorption layer simplifies pixel processing, allowing for higher resolution and smoother carrier diffusion, which is advantageous for light carrier acquisition while also reducing the cost. However, a fundamental issue with thinner absorption layers is the reduced absorption of long-wavelength light.
< Figure 1. Schematic diagram of the InGaAs photodiode image sensor integrated on the Guided-Mode Resonance (GMR) structure proposed in this study (left), a photograph of the fabricated wafer, and a scanning electron microscope (SEM) image of the periodic patterns (right) >
The research team introduced a guided-mode resonance (GMR) structure* that enables high-efficiency light absorption across a wide spectral range from 400 nanometers (nm) to 1,700 nanometers (nm). This wavelength range includes not only visible light but also light the SWIR region, making it valuable for various industrial applications.
*Guided-Mode Resonance (GMR) Structure: A concept used in electromagnetics, a phenomenon in which a specific (light) wave resonates (forming a strong electric/magnetic field) at a specific wavelength. Since energy is maximized under these conditions, it has been used to increase antenna or radar efficiency.
The improved performance in the SWIR region is expected to play a significant role in developing next-generation image sensors with increasingly high resolutions. The GMR structure, in particular, holds potential for further enhancing resolution and other performance metrics through hybrid integration and monolithic 3D integration with complementary metal-oxide-semiconductor (CMOS)-based readout integrated circuits (ROIC).
< Figure 2. Benchmark for state-of-the-art InGaAs-based SWIR pixels with simulated EQE lines as a function of TAL variation. Performance is maintained while reducing the absorption layer thickness from 2.1 micrometers or more to 1 micrometer or less while reducing it by 50% to 70% >
The research team has significantly enhanced international competitiveness in low-power devices and ultra-high-resolution imaging technology, opening up possibilities for applications in digital cameras, security systems, medical and industrial image sensors, as well as future ultra-high-resolution sensors for autonomous driving, aerospace, and satellite observation.
Professor Sang Hyun Kim, the lead researcher, commented, “This research demonstrates that significantly higher performance than existing technologies can be achieved even with ultra-thin absorption layers.”
< Figure 3. Top optical microscope image and cross-sectional scanning electron microscope image of the InGaAs photodiode image sensor fabricated on the GMR structure (left). Improved quantum efficiency performance of the ultra-thin image sensor (red) fabricated with the technology proposed in this study (right) >
The results of this research were published on 15th of November, in the prestigious international journal Light: Science & Applications (JCR 2.9%, IF=20.6), with Professor Dae-Myung Geum of Inha University (formerly a KAIST postdoctoral researcher) and Dr. Jinha Lim (currently a postdoctoral researcher at Yale University) as co-first authors. (Paper title: “Highly-efficient (>70%) and Wide-spectral (400 nm -1700 nm) sub-micron-thick InGaAs photodiodes for future high-resolution image sensors”)
This study was supported by the National Research Foundation of Korea.
2024.11.22 View 2785 -
KAIST Researchers Suggest an Extraordinary Alternative to Petroleum-based PET - Bacteria!
< (From left) Dr. Cindy Pricilia, Ph.D. Candidate Cheon Woo Moon, Distinguished Professor Sang Yup Lee >
Currently, the world is suffering from environmental problems caused by plastic waste. The KAIST research team has succeeded in producing a microbial-based plastic that is biodegradable and can replace existing PET bottles, making it a hot topic.
Our university announced on the 7th of November that the research team of Distinguished Professor Sang Yup Lee of the Department of Chemical and Biomolecular Engineering has succeeded in developing a microbial strain that efficiently produces pseudoaromatic polyester monomer to replace polyethylene terephthalate (PET) using systems metabolic engineering.
Pseudoaromatic dicarboxylic acids have better physical properties and higher biodegradability than aromatic polyester (PET) when synthesized as polymers, and are attracting attention as an eco-friendly monomer* that can be synthesized into polymers. The production of pseudoaromatic dicarboxylic acids through chemical methods has the problems of low yield and selectivity, complex reaction conditions, and the generation of hazardous waste.
*Monomer: A material for making polymers, which is used to synthesize polymers by polymerizing monomers together
< Figure. Overview of pseudoaromatic dicarboxylic acid production using metabolically engineered C. glutamicum. >
To solve this problem, Professor Sang Yup Lee's research team used metabolic engineering to develop a microbial strain that efficiently produces five types of pseudoaromatic dicarboxylic acids, including 2-pyrone-4,6-dicarboxylic acid and four types of pyridine dicarboxylic acids (2,3-, 2,4-, 2,5-, 2,6-pyridine dicarboxylic acids), in Corynebacterium, a bacterium mainly used for amino acid production.
The research team used metabolic engineering techniques to build a platform microbial strain that enhances the metabolic flow of protocatechuic acid, which is used as a precursor for several pseudoaromatic dicarboxylic acids, and prevents the loss of precursors.
Based on this, the genetic manipulation target was discovered through transcriptome analysis, producing 76.17 g/L of 2-pyrone-4,6-dicarboxylic acid, and by newly discovering and constructing three types of pyridine dicarboxylic acid production metabolic pathways, successfully producing 2.79 g/L of 2,3-pyridine dicarboxylic acid, 0.49 g/L of 2,4-pyridine dicarboxylic acid, and 1.42 g/L of 2,5-pyridine dicarboxylic acid.
In addition, the research team confirmed the production of 15.01 g/L through the construction and reinforcement of the 2,6-pyridine dicarboxylic acid biosynthesis pathway, successfully producing a total of five similar aromatic dicarboxylic acids with high efficiency.
In conclusion, the team succeeded in producing 2,4-, 2,5-, and 2,6-pyridine dicarboxylic acids at the world's highest concentration. In particular, 2,4-, 2,5-pyridine dicarboxylic acid achieved production on the scale of g/L, which was previously produced in extremely small amounts (mg/L).
Based on this study, it is expected that it will be applied to various polyester production industrial processes, and it is also expected that it will be actively utilized in research on the production of similar aromatic polyesters.
Professor Sang Yup Lee, the corresponding author, said, “The significance lies in the fact that we have developed an eco-friendly technology that efficiently produces similar aromatic polyester monomers based on microorganisms,” and “This study will help the microorganism-based bio-monomer industry replace the petrochemical-based chemical industry in the future.”
The results of this study were published in the international academic journal, the Proceedings of the National Academy of Sciences of United States of America (PNAS) on October 30th.
※ Paper title: Metabolic engineering of Corynebacterium glutamicum for the production of pyrone and pyridine dicarboxylic acids
※ Author information: Jae Sung Cho (co-first author), Zi Wei Luo (co-first author), Cheon Woo Moon (co-first author), Cindy Prabowo (co-author), Sang Yup Lee (corresponding author) - a total of 5 people
This study was conducted with the support of the Development of Next-generation Biorefinery Platform Technologies for Leading Bio-based Chemicals Industry Project and the Development of Platform Technologies of Microbial Cell Factories for the Next-generation Biorefineries Project (Project leader: Professor Sang Yup Lee) from the National Research Foundation supported by the Ministry of Science and Technology and ICT of Korea.
2024.11.08 View 5609 -
A KAIST Team Develops Face-Conforming LED Mask Showing 340% Improved Efficacy in Deep Skin Elasticity
- A KAIST research team led by Professor Keon Jae Lee has developed a deep skin-stimulating LED mask which has been verified in clinical trials to improve dermis elasticity by 340%.
< Figure 1. Overall concept of face-fit surface-lighting micro-LEDs (FSLED) mask. a. Optical image of the FSLED mask showing uniform surface-lighting. schematic illustration of the FSLED mask. The 2D to 3D transformation procedure b. Difference in cosmetic effect on deep skin elasticity, wrinkles, and sagging between FSLED mask and CLED mask. (improvement percentage in eight weeks) >
Conventional LED masks, with their rigid design, fail to conform closely to the skin's contours. This limitation causes substantial light reflection, with up to 90% reflected over a distance of 2 cm, reducing light penetration and limiting stimulation of the deep skin layers essential for effective skin rejuvenation.
To address these challenges, Professor Lee's team developed a face-conforming surface lighting micro-LED (FSLED) mask, which can provide uniform photostimulation to the dermis. The key technology lies in the mask's ability to deliver uniform light to deep skin tissues while maintaining a conformal skin attachment. This is achieved through a 3D origami structure, integrated with 3,770 micro-LEDs and flexible surface light-diffusion layer, minimizing the gaps between the light source and the skin.
In clinical trials involving 33 participants, the FSLED mask demonstrated a 340% improvement in deep skin elasticity compared to conventional LED masks, proving its efficacy in significantly reducing skin wrinkles, sagging and aging.
Professor Keon Jae Lee said, “The FSLED mask provides cosmetic benefits to the entire facial dermis without the side effects of low-temperature burns, making home-care anti-aging treatment that enhances the quality of human life possible. The product is being manufactured by Fronics, KAIST startup company, and will be distributed globally through Amorepacific's network, with sales starting in November.”
This result titled “Clinical Validation of Face-fit Surface-lighting Micro Light-emitting Diode Mask for Skin Anti-aging Treatment”, in which Min Seo Kim, a student of the Master-Doctorate integrated program, and Jaehun An, a Ph.D. candidate, in the Department of Materials Science and Engineering of KAIST, took part as co-first authors, was published in Advanced Materials on October 22nd, 2024 (DOI: 10.1002/adma.202411651).
Introductory Video: Face-conforming surface LED mask for skin anti-aging ( https://www.youtube.com/watch?v=kSccLwx8N_w )
2024.10.29 View 4240 -
KAIST Changes the Paradigm of Drug Discovery with World's First Atomic Editing
In pioneering drug development, the new technology that enables the easy and rapid editing of key atoms responsible for drug efficacy has been regarded as a fundamental and "dream" technology, revolutionizing the process of discovering potential drug candidates. KAIST researchers have become the first in the world to successfully develop single-atom editing technology that maximizes drug efficacy.
On October 8th, KAIST (represented by President Kwang-Hyung Lee) announced that Professor Yoonsu Park’s research team from the Department of Chemistry successfully developed technology that enables the easy editing and correction of oxygen atoms in furan compounds into nitrogen atoms, directly converting them into pyrrole frameworks, which are widely used in pharmaceuticals.
< Image. Conceptual image illustrating the main idea of the research >
This research was published in the prestigious scientific journal Science on October 3rd under the title "Photocatalytic Furan-to-Pyrrole Conversion."
Many drugs have complex chemical structures, but their efficacy is often determined by a single critical atom. Atoms like oxygen and nitrogen play a central role in enhancing the pharmacological effects of these drugs, particularly against viruses.
This phenomenon, where the introduction of specific atoms into a drug molecule dramatically affects its efficacy, is known as the "Single Atom Effect." In leading-edge drug development, discovering atoms that maximize drug efficacy is key.
However, evaluating the Single Atom Effect has traditionally required multi-step, costly synthesis processes, as it has been difficult to selectively edit single atoms within stable ring structures containing oxygen or nitrogen.
Professor Park’s team overcame this challenge by introducing a photocatalyst that uses light energy. They developed a photocatalyst that acts as a “molecular scissor,” freely cutting and attaching five-membered rings, enabling single-atom editing at room temperature and atmospheric pressure—a world first.
The team discovered a new reaction mechanism in which the excited molecular scissor removes oxygen from furan via single-electron oxidation and then sequentially adds a nitrogen atom.
Donghyeon Kim and Jaehyun You, the study's first authors and candidates in KAIST’s integrated master's and doctoral program in the Department of Chemistry, explained that this technique offers high versatility by utilizing light energy to replace harsh conditions. They further noted that the technology enables selective editing, even when applied to complex natural products or pharmaceuticals. Professor Yoonsu Park, who led the research, remarked, "This breakthrough, which allows for the selective editing of five-membered organic ring structures, will open new doors for building libraries of drug candidates, a key challenge in pharmaceuticals. I hope this foundational technology will be used to revolutionize the drug development process."
The significance of this research was highlighted in the Perspective section of Science, a feature where a peer scientist of prominence outside of the project group provides commentary on an impactful research.
This research was supported by the National Research Foundation of Korea’s Creative Research Program, the Cross-Generation Collaborative Lab Project at KAIST, and the POSCO Science Fellowship of the POSCO TJ Park Foundation.
2024.10.11 View 3422 -
Professor Jimin Park and Dr. Inho Kim join the ranks of the 2024 "35 Innovators Under 35" by the MIT Technology Review
< (From left) Professor Jimin Park of the Department of Chemical and Biomolecular Engineering and Dr. Inho Kim, a graduate of the Department of Materials Science and Engineering >
KAIST (represented by President Kwang-Hyung Lee) announced on the 13th of September that Professor Jimin Park from KAIST’s Department of Chemical and Biomolecular Engineering and Dr. Inho Kim, a graduate from the Department of Materials Science and Engineering (currently a postdoctoral researcher at Caltech), were selected by the MIT Technology Review as the 2024 "35 Innovators Under 35”.
The MIT Technology Review, first published in 1899 by the Massachusetts Institute of Technology, is the world’s oldest and most influential magazine on science and technology, offering in-depth analysis across various technology fields, expanding knowledge and providing insights into cutting-edge technology trends.
Since 1999, the magazine has annually named 35 innovators under the age of 35, recognizing young talents making groundbreaking contributions in modern technology fields. The recognition is globally considered a prestigious honor and a dream for young researchers in the science and technology community.
< Image 1. Introduction for Professor Jimin Park at the Meet 35 Innovators Under 35 Summit 2024 >
Professor Jimin Park is developing next-generation bio-interfaces that link artificial materials with living organisms, and is engaged in advanced research in areas such as digital healthcare and carbon-neutral compound manufacturing technologies. In 2014, Professor Park was also recognized as one of the ‘Asia Pacific Innovators Under 35’ by the MIT Technology Review, which highlights young scientists in the Asia-Pacific region.
Professor Park responded, “It’s a great honor to be named as one of the young innovators by the MIT Technology Review, a symbol of innovation with a long history. I will continue to pursue challenging, interdisciplinary research to develop next-generation interfaces that seamlessly connect artificial materials and living organisms, from atomic to system levels.”
< Image 2. Introduction for Dr. Inho Kim as the 2024 Innovator of Materials Science for 35 Innovators Under 35 >
Dr. Inho Kim, who earned his PhD from KAIST in 2020 under the supervision of Professor Sang Ouk Kim from the Department of Materials Science and Engineering, recently succeeded in developing a new artificial muscle using composite fibers. This new material is considered the most human-like muscle ever reported in scientific literature, while also being 17 times stronger than natural human muscle.
Dr. Kim is researching the application of artificial muscle fibers in next-generation wearable assistive devices that move more naturally, like humans or animals, noting that the fibers are lightweight, flexible, and exhibit conductivity during contraction, enabling real-time feedback. Recognized for this potential, Dr. Inho Kim was named one of the '35 Innovators Under 35' this year, making him the first researcher to win the honor with the research conducted at KAIST and a PhD earned from Korea.
Dr. Kim stated, “I aim to develop robots using these new materials that can replace today’s expensive and heavy exoskeleton suits by eliminating motors and rigid frames. This will significantly reduce costs and allow for better customization, making cutting-edge technology more accessible to those who need it most, like children with cerebral palsy.”
2024.09.13 View 4456 -
KAIST and Merck Sign MOU to Boost Biotech Innovation
< (From left) KAIST President Kwang-Hyung Lee and Merck CEO Matthias Heinzel >
KAIST (President Kwang-Hyung Lee) signed a Memorandum of Understanding (MOU) with Merck Life Science (CEO Matthias Heinzel) on May 29 to foster innovation and technology creation in advanced biotechnology.
Since May of last year, the two institutions have been discussing multidimensional innovation programs and will now focus on industry-academia cooperation to tackle bioindustry challenges with this MOU as a foundation.
KAIST will conduct joint research projects in various advanced biotechnology fields, such as synthetic biology, mRNA, cell line engineering, and organoids, using the chemical and biological portfolios provided by Merck.
Additionally, KAIST will establish an Experience Lab in collaboration with the Department of Materials Science and Engineering and the Graduate School of Medical Science and Engineering. This lab will support the discovery and analysis of candidate substances in materials science and biology.
Programs to enhance researchers' capabilities will also be offered. Scholarships for graduate students and awards for professors will be implemented. Researchers will have opportunities to participate in global academic events and educational programs hosted by Merck, such as the Curious 2024 Future Insight Conference and the Innovation Cup.
M Ventures, a venture capital subsidiary of Merck Group, will collaborate with KAIST's startup institute to support technology commercialization and continue to develop their startup ecosystem.
The signing ceremony at KAIST's main campus in Daejeon was attended by the CEO of Merck Life Science and the President of KAIST along with representatives from both institutions.
Matthias Heinzel, a member of the Executive Board of Merck and CEO Life Science, said, “This agreement with KAIST is a significant step toward accelerating the development of the life science industry both in Korea and globally. Advancing life science research and fostering the next generation of scientists is essential for discovering new medicines to meet global health needs.”
President Kwang-Hyung Lee responded, “We are pleased to share a vision for scientific advancement with Merck, a leading global technology company. We anticipate that this partnership will strengthen the connection between Merck’s life science business and the global scientific community.”
In March, Merck, a global science and technology company with over 350 years of history, announced a plan to invest 430 billion KRW (€300 million) to build a bioprocessing center in Daejeon, where KAIST is located. This is Merck's largest investment in the Asia-Pacific region.
2024.05.30 View 4976 -
KAIST research team develops a cheap and safe redox flow battery
Redox flow batteries, one of the potential replacements for the widely used lithium-ion secondary batteries, can be utilized as new and renewable energy as well as for energy storage systems (ESS) thanks to their low cost, low flammability, and long lifetime of over 20 years. Since the price of vanadium, the most widely used active material for redox flow batteries, has been rising in recent years, scientists have been actively searching for redox materials to replace it.
On March 23, a joint research team led by Professors Hye Ryung Byon and Mu-Hyun Baik from the KAIST Department of Chemistry, and Professor Jongcheol Seo from the POSTECH Department of Chemistry announced that they had developed a highly soluble and stable organic redox-active molecule for use in aqueous redox flow batteries.
The research team focused on developing aqueous redox flow batteries by redesigning an organic molecule. It is possible to control the solubility and electrochemical redox potential of organic molecules by engineering their design, which makes them a promising active material candidate with possibly higher energy storage capabilities than vanadium. Most organic redox-active molecules have low solubilities or have slow chemical stability during redox reactions. Low solubility means low energy storage capacity and low chemical stability leads to reduced cycle performance. For this research, the team chose naphthalene diimide (NDI) as their active molecule. Until now, there was little research done on NDI despite its high chemical stability, as it shows low solubility in aqueous electrolyte solutions.
Although NDI molecules are almost insoluble in water, the research team tethered four ammonium functionalities and achieved a solubility as high as 1.5M* in water. In addition, they confirmed that when a 1M solution of NDI was used in neutral redox flow batteries for 500 cycles, 98% of its capacity was maintained. This means 0.004% capacity decay per cycle, and only 2% of its capacity would be lost if the battery were to be operated for 45 days.
Furthermore, the developed NDI molecule can save two electrons per molecule, and the team proved that 2M of electrons could be stored in every 1M of NDI solution used. For reference, vanadium used in vanadium redox flow batteries, which require a highly concentrated sulfuric acid solution, has a solubility of about 1.6M and can only hold one electron per molecule, meaning it can store a total of 1.6M of electrons. Therefore, the newly developed NDI active molecule shows a higher storage capacity compared to existing vanadium devices.
*1M (mol/L): 6.022 x 1023 active molecules are present in 1L of solution
This paper, written by co-first authors Research Professor Vikram Singh, and Ph.D. candidates Seongyeon Kwon and Yunseop Choi, was published in the online version of Advanced Materials on February 7 under the title, Controlling π-π interactions of highly soluble naphthalene diimide derivatives for neutral pH aqueous redox flow batteries. Ph.D. Candidate Yelim Yi and Professor Mi Hee Lee’s team from the KAIST Department of Chemistry also contributed to the study by conducting electron paramagnetic resonance analyses.
Professor Hye Ryung Byon said, “We have demonstrated the principles of molecular design by modifying an existing organic active molecule with low solubility and utilizing it as an active molecule for redox flow batteries. We have also shown that during a redox reaction, we can use molecular interactions to suppress the chemical reactivity of radically formed molecules.”
She added, “Should this be used later for aqueous redox flow batteries, along with its high energy density and high solubility, it would also have the advantage of being available for use in neutral pH electrolytes. Vanadium redox flow batteries currently use acidic solutions, which cause corrosion, and we expect our molecule to solve this issue. Since existing lithium ion-based ESS are flammable, we must develop safer and cheaper next-generation ESS, and our research has shown great promise in addressing this.”
This research was funded by Samsung Research Funding & Incubation Center, the Institute for Basic Science, and the National Research Foundation.
Figure 1. (a) Structures of various NDI molecules. (b) Solubility of NDI molecules in water (black bars) and aqueous electrolytes including KCl electrolyte (blue bars). (c–d) Structural changes of the molecules as the developed NDI molecule stores two electrons. (c) Illustration of cluster combination and separation of NDI molecules developed during redox reaction and (d) Snapshot of the MD simulation. NDI molecules prepared from the left, formation of bimolecular sieve and tetramolecular sieve clusters after the first reductive reaction, and a single molecule with a three-dimensional structure after the second reduction.
Figure 2. Performance results of an aqueous redox flow battery using 1M of the developed NDI molecule as the cathode electrolyte and 3.1M of ammonium iodine as the anode electrolyte. Using 1.5 M KCl solution. (a) A schematic diagram of a redox flow battery. (b) Voltage-capacity graph according to cycle in a redox flow battery. (c) Graphs of capacity and coulombs, voltage, and energy efficiency maintained at 500 cycles.
2023.04.03 View 5869 -
KAIST researchers devises a technology to utilize ultrahigh-resolution micro-LED with 40% reduced self-generated heat
In the digitized modern life, various forms of future displays, such as wearable and rollable displays are required. More and more people are wanting to connect to the virtual world whenever and wherever with the use of their smartglasses or smartwatches. Even further, we’ve been hearing about medical diagnosis kit on a shirt and a theatre-hat. However, it is not quite here in our hands yet due to technical limitations of being unable to fit as many pixels as a limited surface area of a glasses while keeping the power consumption at the a level that a hand held battery can supply, all the while the resolution of 4K+ is needed in order to perfectly immerse the users into the augmented or virtual reality through a wireless smartglasses or whatever the device.
KAIST (President Kwang Hyung Lee) announced on the 22nd that Professor Sang Hyeon Kim's research team of the Department of Electrical and Electronic Engineering re-examined the phenomenon of efficiency degradation of micro-LEDs with pixels in a size of micrometers (μm, one millionth of a meter) and found that it was possible to fundamentally resolve the problem by the use of epitaxial structure engineering.
Epitaxy refers to the process of stacking gallium nitride crystals that are used as a light emitting body on top of an ultrapure silicon or sapphire substrate used for μLEDs as a medium.
μLED is being actively studied because it has the advantages of superior brightness, contrast ratio, and lifespan compared to OLED. In 2018, Samsung Electronics commercialized a product equipped with μLED called 'The Wall'. And there is a prospect that Apple may be launching a μLED-mounted product in 2025.
In order to manufacture μLEDs, pixels are formed by cutting the epitaxial structure grown on a wafer into a cylinder or cuboid shape through an etching process, and this etching process is accompanied by a plasma-based process. However, these plasmas generate defects on the side of the pixel during the pixel formation process.
Therefore, as the pixel size becomes smaller and the resolution increases, the ratio of the surface area to the volume of the pixel increases, and defects on the side of the device that occur during processing further reduce the device efficiency of the μLED. Accordingly, a considerable amount of research has been conducted on mitigating or removing sidewall defects, but this method has a limit to the degree of improvement as it must be done at the post-processing stage after the grown of the epitaxial structure is finished.
The research team identified that there is a difference in the current moving to the sidewall of the μLED depending on the epitaxial structure during μLED device operation, and based on the findings, the team built a structure that is not sensitive to sidewall defects to solve the problem of reduced efficiency due to miniaturization of μLED devices. In addition, the proposed structure reduced the self-generated heat while the device was running by about 40% compared to the existing structure, which is also of great significance in commercialization of ultrahigh-resolution μLED displays.
This study, which was led by Woo Jin Baek of Professor Sang Hyeon Kim's research team at the KAIST School of Electrical and Electronic Engineering as the first author with guidance by Professor Sang Hyeon Kim and Professor Dae-Myeong Geum of the Chungbuk National University (who was with the team as a postdoctoral researcher at the time) as corresponding authors, was published in the international journal, 'Nature Communications' on March 17th. (Title of the paper: Ultra-low-current driven InGaN blue micro light-emitting diodes for electrically efficient and self-heating relaxed microdisplay).
Professor Sang Hyeon Kim said, "This technological development has great meaning in identifying the cause of the drop in efficiency, which was an obstacle to miniaturization of μLED, and solving it with the design of the epitaxial structure.“ He added, ”We are looking forward to it being used in manufacturing of ultrahigh-resolution displays in the future."
This research was carried out with the support of the Samsung Future Technology Incubation Center.
Figure 1. Image of electroluminescence distribution of μLEDs fabricated from epitaxial structures with quantum barriers of different thicknesses while the current is running
Figure 2. Thermal distribution images of devices fabricated with different epitaxial structures under the same amount of light.
Figure 3. Normalized external quantum efficiency of the device fabricated with the optimized epitaxial structure by sizes.
2023.03.23 View 6103 -
KAIST researchers develops a tech to enable production of ultrahigh-resolution LED with sub-micrometer scale pixels
Ultrahigh-resolution displays are an essential element for developing next-generation electronic products such as virtual reality (VR), augmented reality (AR), and smart watches, and can be applied not only to head-mounted displays, but also to smart glasses and smart lenses. The technology developed through this research is expected to be used to make such next-generation ultrahigh-resolution displays and other various sub-micro optoelectronic devices.
KAIST (President Kwang Hyung Lee) announced on the 22nd that Professor Yong-Hoon Cho's research team of KAIST Department of Physics developed the core technology for an ultrahigh resolution light-emitting diode (LED) display that can realize 0.5 micron-scale pixels smaller than 1/100 of the average hair thickness (about 100 microns) using focused ion beams.
Commonly, pixelation of ultrahigh-resolution LED displays usually relies on the etching method that physically cuts the area around the pixel, but as the pixel becomes smaller due to the occurrence of various defects around it, leading to side-effects of having leakage of current increased and light-emission efficiency decreased. In addition, various complex processes such as patterning for pixelation and post-processing for prevention of leakage current are required.
Professor Yong-Hoon Cho's research team developed a technology that can create pixels down to the size of a microscale without the complicated pre- and post-processing using a focused ion beam. This method has the advantage of being able to freely set the shape of the emitting pixel without causing any structural deformation on the material surface by controlling the intensity of the focused ion beam.
The focused ion beam technology has been widely used for ultrahigh-magnification imaging and nanostructure fabrication in fields such as materials engineering and biology. However, when a focused ion beam is used on a light emitting body such as an LED, light emission of a portion hit by the beam and a surrounding area rapidly decreases, which has been a barrier to fabricating a nano-scale light emitting structure. Upon facing this issue, Professor Cho's research team began the research on the idea that if they turned things around to use these problematic phenomena, they can be used in ultra-fine pixelation method on a sub-micron scale.
The research team used a focused ion beam whose intensity was softened to the extent that the surface was not shaved, and found that not only the light-emission rapidly decreased in the area hit by the focused ion beam, but also the local resistance greatly increased. As a result, while the surface of the LED is kept flat, the portion hit by the focused ion beam is optically and electrically isolated, enabling pixelation for independent operation.
Professor Yong-Hoon Cho, who led the research, said, “We have newly developed a technology that can create sub-micron-scale pixels without complicated processes using a focused ion beam, which will be a base technology that can be applied to next-generation ultrahigh-resolution displays and nano-photoelectronic devices.”
This research in which the Master's student Ji-Hwan Moon and the Ph.D. student Baul Kim of KAIST Department of Physics participated as co-first authors, was carried out with the support of the National Research Foundation of Korea's Support Program for Mid-Career Researchers and the Institute of Information and Communications Technology Planning and Evaluation. It was published online in 'Advanced Materials' on February 13, and was also selected as the internal cover of the next offline edition. (Title: Electrically Driven Sub-Micron Light-Emitting Diode Arrays Using Maskless and Etching-Free Pixelation)
Figure 1. Schematic diagram of the technology for ultrahigh density sub-micron-sized pixels through He focused ion beam (FIB) irradiation on an LED device
Figure 2. Ultra-high-density pixelation technology of micro light-emitting diodes (μLED) through He focused ion beam (FIB) irradiation
Figure 3. Rectangular pixels of different sizes (surface structure picture and luminescence picture) realized by a focused ion beam. Luminescence pictures of pixel arrays ranging in size from 20 µm x 20 µm to 0.5 µm x 0.5 µm, with surface flatness maintained.
2023.03.08 View 6566