연구 > 연구성과 - KAIST 전기 및 전자공학부

Professor Hyun Myung’s Team Wins First Place at Prestigious International Robotics Conference Challenge

<(From left) Daebeom Kim (Ph.D. candidate, team leader), Seungjae Lee (Ph.D. candidate), Seoyeon Jang (Ph.D. candidate), Jei Kong (M.S. candidate), Professor Hyun Myung>

The Urban Robotics Lab, led by Professor Hyun Myung from the School of Electrical Engineering, secured the first place overall at the “Nothing Stands Still (NSS) Challenge 2025,”held in the “Future of Construction: Safe, Reliable, and Precise Robots in Construction Environments” workshop at the 2025 IEEE International Conference on Robotics and Automation (ICRA), the world’s premier robotics conference, which took place in Atlanta, USA, from May 19 to 23, 2025.

NSS Challenge is co-hosted by HILTI, a global construction company based in Liechtenstein, and Gradient Spaces Group at Stanford University. It is an advanced version of HILTI SLAM (Simultaneous Localization and Mapping) Challenge, which has been held since 2021, and is now considered one of the most prestigious challenges at ICRA.

This challenge evaluates how accurately and robustly LiDAR scan data, collected across various time periods in structurally dynamic environments such as construction and industrial sites, can be registered. Rather than focusing solely on single-instance registration accuracy, it emphasizes multi-session localization and mapping (Multi-session SLAM) technologies capable of handling structural changes over time, making it one of the most technically demanding competitions in the field.

Urban Robotics Lab team secured the first place overall by a significant margin over National Taiwan University (3rd place) and Northwestern Polytechnical University of China (2nd place), with their novel localization and mapping technology that solves the alignment problem of LiDAR data collected across diverse periods and locations. The winning team will be awarded a prize of $4,000.

<Fig. 1. Example of multiway registration of LiDAR scans from different time periods>

Urban Robotics Lab team developed a multiway registration framework capable of robustly aligning multiple scans without prior connectivity information. This framework consists of three core components: CubicFeat, an algorithm that summarizes local features within each scan and identifies correspondences; Quatro, a global registration algorithm that aligns scans based on those correspondences; and Chamelion, a refinement module based on change detection. This combination of techniques shows stable alignment performance even in highly dynamic industrial environments by focusing on static structural elements.

<Fig. 2. Example of change detection using the Chamelion algorithm>

LiDAR scan registration technology is a core component of SLAM used in various autonomous systems, including self-driving cars, autonomous robots, legged platforms, aerial vehicles, and maritime navigation systems. In particular, the awarded technology has demonstrated exceptional precision in estimating the relative poses between scans in complex environments, proving both its academic significance and practical applicability in industry.

Professor Hyun Myung of the School of Electrical Engineering at KAIST stated, “It is deeply meaningful to have demonstrated our technological capabilities by solving multi-session SLAM challenges in complex and constantly changing industrial environments.” He added, “I am grateful to the students who persevered and never gave up, even when many other teams withdrew due to the difficulty of the competition.”

The Urban Robotics Lab team first participated in the SLAM Challenge in 2022, winning 2nd place in the academic division, and in 2023, they took 1st place overall in the LiDAR division and 1st place in the academic division of the vision track.

SID 2025 Distinguished Student Paper Award and Young Leadership Conference Selection, Hyejeong Yeon, Ph.D. Candidate from Prof. Kyung Cheol Choi’s Lab (ADNC Lab)

<Ph.D. candidate Hyejeong Yeon>

Hyejeong Yeon, a Ph.D. candidate in the School of Electrical and Electronic Engineering at KAIST under the supervision of Professor Kyung Cheol Choi, received the Distinguished Student Paper Award at SID 2025 (Society for Information Display 2025 International Symposium – Display Week 2025) held from May 11 to 16.

SID is the most prestigious international symposium in the field of display technology. In 2025, a total of 925 papers from 20 countries were submitted, and outstanding papers were selected by each technical committee.

The paper by Hyejeong Yeon, a Ph.D. candidate, was recognized by the Flexible Displays Committee for its excellence, and was selected as a Distinguished Student Paper, and the title of the awarded paper is: “Flexible Bifacial OLED-Based Photomedicine for User-Friendly Healthcare Platforms.”

The research was published in the Journal of the SID under the title : “Wearable User-Centric Phototherapeutics with Bifacial OLEDs for At-Home Wound Healing.” Furthermore, Yeon was selected to present her work at the Young Leadership Conference, a special session for promising young researchers, where her study was chosen as one of the top 10 outstanding papers of the year.

Conference: SID 2025 (Society for Information Display 2025 International Symposium – Display Week 2025)
Date: May 11–16, 2025
Award: Distinguished Student Paper Award
Paper Title: Flexible Bifacial OLED-Based Photomedicine for User-Friendly Healthcare Platforms
Paper Link: https://doi.org/10.1002/jsid.2076

EE Prof. Ian Oakley’s Research Team Develops Next-Generation Wearable Interaction Technologies Using Around-Device Sensing

〈(from left) Ph.D. candidate Jiwan Kim, Professor Ian Oakley and Ph.D. candidate Mingyu Han 〉

When will the futuristic vision of natural gesture-based interaction with computers, as seen in sci-fi films like Iron Man, become a reality? Researchers from the KAIST School of Electrical Engineering have developed AI technologies that enable natural and expressive input for wearable devices.

Professor Ian Oakley’s research team at KAIST’s School of Electrical Engineering has developed two systems: BudsID, a finger-identification system for wireless earbuds, and SonarSelect, which enables mid-air gesture input on commercial smartwatches. These two studies were presented at the ACM Conference on Human Factors in Computing Systems (CHI)—the world’s premier conference in the field of human-computer interaction—held in Yokohama, Japan from April 26 to May 1. The presentations were part of the “Earables and Hearable” and “Interaction Techniques” sessions, respectively.

BudsID uses magnetic sensing to distinguish between fingers based on magnetic field changes that occur when a user wearing a magnetic ring touches an earbud. A lightweight deep learning model identifies which finger is used, allowing different functions to be assigned to each finger, thus expanding the input expressiveness of wireless earbuds.

This magnetic sensing system for wireless earbuds allows users to go beyond traditional interactions like play, pause, or call handling. By mapping different functions or input commands to individual fingers, the interaction capabilities can extend to augmented reality device control and beyond.

SonarSelect leverages active sonar sensing using only the built-in microphone, speaker, and motion sensors of a commercial smartwatch. It recognizes mid-air gestures around the device, enabling precise pointer manipulation and target selection.

This gesture interaction technology, based on finger movements detected via active sonar, addresses usability issues of small smartwatch screens and touch occlusion. It enables delicate 3D spatial interactions around the device.

Jiwan Kim, first author of both papers, said, “We hope our research into around-device sensing for wearable interaction technologies will help shape the future of how people interact with wearable computing devices.”

Professor Ian Oakley’s research team has made both project systems available as open source, allowing researchers and industry professionals to freely use the technology.

[BudsID]

Title: BudsID: Mobile-Ready and Expressive Finger Identification Input for Earbuds
Authors: Jiwan Kim, Mingyu Han, and Ian Oakley
DOI: https://dl.acm.org/doi/10.1145/3706598.3714133
Open Source: https://github.com/witlab-kaist/BudsID

[SonarSelect]

Title: Cross, Dwell, or Pinch: Designing and Evaluating Around-Device Selection Methods for Unmodified Smartwatches
Authors: Jiwan Kim, Jiwan Son, and Ian Oakley
DOI: https://dl.acm.org/doi/10.1145/3706598.3714308
Open Source: https://github.com/witlab-kaist/SonarSelect

This research was supported by the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (grants 2023R1A2C1004046, RS-2024-00407732) and the Institute for Information & Communications Technology Planning & Evaluation (IITP) under the University ICT Research Center (ITRC) support program (IITP-2024-RS-2024-00436398).

EE Prof. Sanghyeon Kim’s Lab Selected for Samsung Research Funding & Incubation Center for Future Technology’s New Project for the First Half of 2025

EE Professor Sanghyeon Kim’s lab has been selected for one of five new ICT projects for the first half of this year by the Samsung Research Funding & Incubation Center for Future Technology.

The Samsung Research Funding & Incubation Center for Future Technology is a funding initiative that supports innovative research projects across a wide range of fields, from natural sciences to engineering, with the aim of advancing science, technology, and industry in Korea.

Professor Kim’s lab will carry out a project titled “Low-Loss Active Power Delivery Network with Embedded On-Chip Voltage Regulator for Ultra-Low Power Computing” The research team plans to explore a solution to the power delivery problem, which has recently emerged as a key issue in the fields of semiconductor chips and packaging. Specifically, they will investigate a method of delivering power at high voltage and stepping it down on the backside of the chip.

The goal is to implement an on-chip voltage regulator using GaN-based switches, which have excellent material potential, and ferroelectric capacitors. Ultimately, the core idea is to integrate this system as an active component of the backside power delivery network (BSPDN).

Meanwhile, the foundational concept of this project was presented by the research team at IEDM — one of the three major conferences in the semiconductor field—in December last year, and improved technologies will be presented at the upcoming VLSI Symposium in June.

EE Professors Myoungsoo Jung, John Kim, Song Min Kim, Minsoo Rhu Awarded National R&D Grant for The Large-Scale Silicon Project under the ‘K-Cloud Technology Development Program’

< Figure 1. (From left) Professor Myoungsoo Jung, Professor John Kim, Professor Song Min Kim, Professor Minsoo Rhu >

Professors Myoungsoo Jung, John Kim, Song Min Kim, Minsoo Rhu, have recently been awarded 40 billion KRW in national R&D funding by the Ministry of Science and ICT and the Institute of Information & Communications Technology Planning & Evaluation (IITP), as part of the ‘K-Cloud Project’ initiative.

The K-Cloud Project aims to strengthen the domestic cloud industry’s competitiveness by securing world-class low-power, high-performance data center hardware and software core technologies. Under the leadership of Professor Jung, our research team has been selected for the K-Cloud Project that focuses on developing computational memory hardware based on AI infrastructure, AI integration, Compute Express Link (CXL), and chiplet technologies. The research team will receive over 40 billion KRW in research funding over the next four years.

The K-Cloud Project is a national initiative designed to enhance the country’s competitiveness in cloud computing industry, developing hardware and software technologies which are necessary for building datacenters with ultra-high speed and low-power. As part of this K-Cloud Project, the research team, which is led by Prof. Myoungsoo Jung, have been selected to lead programs focused on AI infrastructure, AI integration, Compute Express Link (CXL), and silicon hardware of computational memory based on chiplet technologies, securing 40B KRW in research funding over the next four years.

Specifically, the team will develop a low-power, high-performance SoC for computational memory, which minimizes data movement by performing AI-related computations close to where data is stored. In addition, the team will develop technologies to construct integrated AI systems by interconnecting these devices using CXL, a high-speed interconnect protocol. Finally, the team will apply optimization software based on AI algorithm to complete an AI infrastructure platform and validate its performance using real-world workloads such as large language models (LLMs), retrieval-augmented generation (RAG), and recommendation systems.

< SoC Architecture >

This project, including the development of these core technologies, is led by Panmnesia—a faculty startup founded by Professor Myoungsoo Jung—and involves participation from other KAIST research groups from our department. This includes research teams of Professors John Kim, Minsoo Rhu, and Song Min Kim. In addition, a university-industry consortium comprising Seoul National University, Yonsei University, Korea University, Hanyang University, Chung-Ang University, POSTECH, and UNIST, the Korea Electronics Technology Institute (KETI), and four industry partners is collaborating on the project. External institutions, such as Chung-Ang University Hospital, will also collaborate for real-world validation and demonstration.

Through this effort, we expect that the collaboration between faculty startups and research laboratories originating from our department will produce impactful research outcomes that contribute to both academia and industry.

EE Prof. Sung-Ju Lee Unveils AI Songwriting Companion ‘Amuse’ to Support Music Creation

< (From left) Professor Chris Donahue of Carnegie Mellon University, Ph.D. candidate Yewon Kim of the School of Electrical Engineering at KAIST, and Professor Sung-Ju Lee of the School of Electrical Engineering at KAIST >

Imagine if music creators had a collaborator who could help brainstorm initial ideas or assist when they hit a creative block or someone who could genuinely support exploring various musical directions. A research team at KAIST’s School of Electrical Engineering has developed an AI tool designed to be such a co-creative partner in music composition.

Professor Sung-Ju Lee’s research team at the School of Electrical Engineering has developed an AI-based music creation support system named Amuse. This research was awarded the Best Paper Award, an honor given to only the top 1% of papers, at CHI (ACM Conference on Human Factors in Computing Systems), the world’s leading conference in human-computer interaction, held in Yokohama, Japan from April 26 to May 1.

Amuse is an AI-based system that supports songwriting by transforming diverse forms of inspiration, such as text, images, or audio, into harmonic structures (chord progressions). For example, when a user inputs a phrase like “memories of a warm summer beach,” an image, or a sound clip, Amuse generates and suggests a chord progression that matches the mood and atmosphere of the inspiration.

Unlike conventional generative AI, Amuse respects the user’s creative process and offers a flexible, interactive approach that allows users to modify and integrate the AI’s suggestions, encouraging natural and creative exploration.

The core technology of the Amuse system is a hybrid generation method. It first uses a large language model to generate music chords based on the user’s textual input. Then, a second AI model trained on actual music data filters out unnatural or awkward results through a process called rejection sampling. These two processes are seamlessly integrated to produce musically coherent outcomes.

< (Figure 1) System structure of Amuse. Music-related keywords are extracted from user input, and a chord progression is generated using a large language model and refined via rejection sampling (left). Chords can also be extracted from audio inputs (right). The bottom visualizes the harmonic structure of the generated chords. >

The research team conducted user studies with actual musicians, and the findings suggest that Amuse has strong potential not just as a music-generating tool but as a co-creative partner that enables collaboration between humans and AI.

The study, authored by Ph.D. candidate Yewon Kim(KAIST), Professor Sung-Ju Lee(KAIST), and Professor Chris Donahue (Carnegie Mellon University), demonstrates the creative potential of AI systems for both academia and industry.

Paper Title: Amuse: Human-AI Collaborative Songwriting with Multimodal Inspirations
DOI: https://doi.org/10.1145/3706598.3713818
Project Website: https://nmsl.kaist.ac.kr/projects/amuse/

Professor Sung-Ju Lee stated, “Recent generative AI technologies have raised concerns due to the risk of replicating copyrighted content or producing results that ignore the creator’s intent. Our team was aware of these issues and focused on what creators actually need, prioritizing user-centric design in developing this AI system.”

He added, “Amuse is an attempt to explore collaborative possibilities with AI while maintaining the creator’s agency. We expect it to be a starting point that guides future development of AI-powered music tools toward a more creator-friendly direction.”

This research was supported by the National Research Foundation of Korea (NRF), funded by the Ministry of Science and ICT. (Project No. RS-2024-00337007)

Prof. Shinhyun Choi Selected as Winner of the Hyeon-Woo KAIST Scholastic Award

〈 (From left) President Kwang Hyung Lee and Professor Shinhyun Choi, recipient of the Hyeon-Woo KAIST Scholastic Award 〉

Professor Shinhyun Choi of the School of Electrical Engineering has been selected as the recipient of the Hyeon-Woo KAIST Scholastic Award, hosted by KAIST and sponsored by the Hyeon-Woo Cultural Foundation (Chairman Soo-Il Kwak), in recognition of his achievements in next-generation AI hardware development and innovative semiconductor research.

Professor Choi’s primary research areas focus on the development of future memory and computing devices, including: ▲ Next-generation memory and computing systems using resistive switching devices that are faster and more efficient than conventional methods ▲ Integration with edge computing and neuromorphic computing to enable intelligent computer memory functions ▲Development of more efficient and creative computing and memory device operations, different from the traditional three-terminal transistor structure.

One of his representative achievements is the successful development of an ultra-low-power next-generation phase-change memory (PCM) device optimized for vertical stacking, which reduces electricity consumption by more than 15 times compared to the conventional method that relies on expensive advanced photolithography* processes. * Photolithography: A process that engraves microscopic circuit patterns on silicon wafers for semiconductor chips, which involves advanced technology and high costs.

Furthermore, based on next-generation memory and computing devices, Professor Choi developed new computing hardware (chips) capable of efficiently running AI algorithms, potentially replacing power-hungry chips such as CPUs and GPUs. This achievement enables faster and more efficient data processing and has led to significant accomplishments in practical applications such as smartphones and autonomous driving.

In addition, by analyzing the operating principles of memory devices down to the atomic level based on fundamental physical laws, he has made major contributions in proposing methods to improve memory performance with greater speed and stability.

Professor Choi’s research spans the entire spectrum of semiconductor technology—from material analysis and device development to integrated system applications. His outstanding achievements have been published in top-tier journals such as Nature, Nature Electronics, Nature Communications, and Science Advances.

Professor Choi stated, “It is an honor to receive this meaningful award for my research in IT and AI-related hardware, which are driving major societal changes. I am deeply moved that this research can provide new perspectives to both academia and industry. I will continue to strive to produce research that inspires future scholars and contributes to society.”

Meanwhile, now in its fifth year, the Hyeon-Woo KAIST Scholastic Award was established with donations from Chairman Soo-Il Kwak of the Hyeon-Woo Cultural Foundation to recognize scholars at KAIST who have made outstanding academic achievements. One faculty member is selected each year through a rigorous evaluation by the Hyeon-Woo Foundation Selection Committee and the KAIST Faculty Award Recommendation Committee. The award includes a plaque and a prize of 10 million KRW. This year’s award ceremony was held on April 30 at Jeong Geun-Mo Hall in the KAIST Academic Cultural Complex.

Prof. Hyeonmin Bae Awarded KAIST Research Grand Prize at 2025 Research Day

〈 (From left) President Kwang Hyung Lee and Professor Hyeonmin Bae, recipient of the Research Grand Prize 〉

Professor Hyeonmin Bae from the School of Electrical Engineering was awarded the Grand research prize at the ‘KAIST Research Day 2025’ event held at the Jeong Geun Mo Conference Hall in the Academic Cultural Complex on April 30th.

Professor Bae was recognized for his outstanding achievements in “Research and Development of Quantitative Medical Imaging Ultrasound Equipment Using Artificial Intelligence,” and shared his decade-long research journey in a commemorative lecture at the event.

By integrating artificial intelligence with ultrasound technology, Professor Bae successfully commercialized quantitative ultrasound techniques, previously unattainable. The technological prowess of this innovation was demonstrated through a live demo at the Radiological Society of North America (RSNA) held in Chicago in 2024. This advanced technology can be implemented as software in existing ultrasound equipment, enabling not only early cancer detection but also the diagnosis of critical diseases in major organs such as the lungs, liver, and heart.

Professor Bae expressed his aspirations for the technology: “I hope quantitative ultrasound technology can facilitate more accurate and swift diagnoses, significantly benefiting diverse medical fields. I am committed to continuing my research to enhance global healthcare welfare.”

〈 Group Photo of 2025 KAIST Research Day Awardees 〉

Meanwhile, at this year’s Research Day, Professors Kyeongha Kwon (A Wireless, Implantable Bioelectronic System for Monitoring Urinary Bladder Function Following Surgical Recovery) and Minsoo Rhu (uPIMulator: Pathfinding Future PIM Architectures by Demystifying a Commercial PIM Technology) were selected for ‘KAIST’s Top 10 Research Achievements of 2024.’

Additionally, professors Junil Choi (Next-generation Visible Light Communication Encryption Technology Using Chiral Nanoparticles / Next-generation Communication) and Kyoungsik Yu (Silicon Photonic Integrated Circuits for Quantum Information Processing) were recognized in the ‘Research achievements in 14 leading technologies of the future 2025’

President Kwang Hyung Lee highlighted, ” KAIST aims to become the world’s first and foremost in research, celebrating today at Research Day the outstanding accomplishments of our researchers, and will continue growing as a global research institution that contributes to the nation and humanity through research, leading innovation and convergence”

KAIST Research Day, established in 2016, serves as an annual platform showcasing KAIST’s research and development (R&D) achievements and fostering active interaction among researchers to promote interdisciplinary collaboration.

EE Professor Hyunchul Shim’s Team Wins 3rd Place at A2RL Autonomous Drone Racing Competition

EE Professor Hyunchul Shim and his research team secured an impressive 3rd place overall at the A2RL (Abu Dhabi Autonomous Racing League) Drone Championship League (DCL), held on April 12, 2025, with sponsorship from the UAE government.

The competition took place at the ADNEC Marina in Abu Dhabi, where 14 finalist teams from around the world competed in a highly challenging indoor arena with 12 racing gates. Notably, the race required fully autonomous drone flights using only a single onboard monocular camera, without relying on external cameras, LiDAR, or GPS — underscoring the high level of technological difficulty. The event featured a total prize purse of USD 1 million.

The contest comprised four segments:

Time trials for shortest lap time
Head-to-head tournament against professional drone racing pilots
Four-team simultaneous autonomous flight race
High-speed two-drone drag races in a mirrored head-on format

Professor Shim’s team — consisting of Donghoon Han (team lead), Ph.D. candidate Maulana Azhari, and M.S. students Jein Yoo and Sungjoon Park — demonstrated outstanding performance by leveraging their proprietary vision-inertial localization and agile flight control technologies. As a result, the team was awarded USD 105,000 in prize money.

The competition was organized by A2RL (Abu Dhabi Autonomous Racing League) with support from the UAE government, following a global qualifier held in Fall 2024, through which 14 teams were selected. Of these, 8 teams advanced to the semifinals, and Professor Shim’s team was ultimately selected as one of the four finalists, alongside top-tier teams from TU Delft (Netherlands), TII (Technology Innovation Institute, UAE), and CTU (Czech Technical University).

Demonstrating consistent and reliable performance, the KAIST team secured 3rd place overall. Notably, they achieved 3^rd place in time trial, 2nd place in the world’s first-ever simultaneous autonomous drone race(by four finalist drones), and 2nd place in the head-to-head drag racing event, in which two drones launched toward each other in mirrored high-speed sprints.

Professor Hyunchul Shim is widely recognized as a pioneer in autonomous drone racing, having organized the world’s first autonomous drone racing competition at IROS 2016, one of the two premier international conferences in robotics. His team won 1st place in 2016 and 2nd place in 2018 at that event. In 2019, they also secured 3rd place at the AlphaPilot Challenge hosted by Lockheed Martin in the United States.

Furthermore, Professor Shim’s team achieved back-to-back victories in 2019 and 2020 in the AI Grand Challenge (indoor drone flight category) organized by Korea’s Ministry of Science and ICT, resulting in over KRW 2.4 billion (approx. USD 2 million) as follow-up research funding. These consistent successes across prestigious international and national competitions underscore his leadership and excellence in the field of autonomous aerial robotics.

The A2RL Drone Championship League (DCL) marks the fifth large-scale robotics competition hosted with support from the UAE government since the 2017 Mohamed Bin Zayed International Robotics Challenge (MBZIRC). While Prof. Shim’s team attended these competitions from the beginning with good results, his team won the second place at the MBZIRC Maritime Challenge, in collaboration with Professor Jinwhan Kim’s team from School of Mechanical Engineering at KAIST.

From practical application’s perspective, camera-based autonomous drone racing is gaining global attention not only as an advanced form of E-sports, but also as a critical enabling technology for first-person view (FPV) drones, which have emerged as game-changing tools in modern warfare. This highlights the growing strategic importance of this field.

Professor Shim remarked, “After the earlier competitions were halted due to COVID-19, a significant amount of time passed, and we had to rebuild the team with new students. Despite the difficulty of conducting tests under many constraints including test facilities, we developed an original localization and control system from scratch. Even when we encountered unexpected challenges on-site, we did not give up and continued our research and adaptation within the limited preparation time, which ultimately allowed us to outperform many top international teams.” He added, “In upcoming competitions, we will strive to deliver world-class results with overwhelming capabilities.”

EE Prof. SangHyeon Kim’s Team Develops Room-Temperature Waveguide-integrated Mid-Infrared Photodetector with CMOS-Compatible Solution

〈From left: Inki Kim (PhD candidate, Co-author), Professor SangHyeon Kim (Corresponding author), Dr. Joonsup Shim (First author), and Dr. Jinha Lim (Co-author) 〉

NASA’s James Webb Space Telescope (JWST) utilizes mid-infrared spectroscopy to precisely analyze and identify molecular components such as water vapor and sulfur dioxide in exoplanet’s atmosphere. The key to such mid-infrared analysis—where each molecule exhibits a distinct optical “fingerprint”—lies in highly sensitive photodetector technologies capable of detecting light intensities stably.

EE Prof. SangHyeon Kim’s research team has developed a groundbreaking photodetector capable of detecting a broad range of mid-infrared wavelengths while operating stably at room temperature. This innovation represents a significant advancement toward the commercialization of ultra-compact optical sensing platforms.

The newly developed photodetector is fully compatible with standard CMOS fabrication processes, enabling low-cost and scalable mass production. Its most notable feature is robust, stable operation at room temperature. The research team successfully demonstrated real-time detection of carbon dioxide (CO₂) using this ultra-compact and ultra-thin optical sensor, validating its potential for applications in environmental monitoring and hazardous gas sensing.

Conventional mid-infrared photodetectors typically require cryogenic cooling to mitigate thermal noise at room temperature. These cooling systems increase the overall size, complexity, and cost of the devices, posing challenges for miniaturization and integration into portable or distributed systems. Furthermore, most existing mid-infrared photodetectors are not compatible with CMOS processes, which hinders their large-scale manufacturability and commercial viability.

To address these limitations, Prof. SangHyeon Kim’s research team developed a novel waveguide-integrated photodetector based on a germanium-on-insulator (Ge-OI) photonic platform—leveraging germanium, a group-IV material compatible with CMOS processes. This platform enables broadband mid-infrared detection while ensuring stable operation at room temperature.

〈 Figure 1. Schematic of the germanium-on-insulator waveguide-integrated photodetector for room-temperature mid-infrared sensing (top), and optical microscope image of the fabricated device (bottom) 〉

A “waveguide” is an optical component designed to efficiently guide light along a specific path with minimal loss. To realize diverse on-chip optical functionalities, the integration of waveguide-based optical components—such as waveguide-integrated photodetectors—is essential.

Unlike conventional photodetectors that rely on wavelength-specific bandgap absorption, the newly developed photodetector exploits the bolometric effect*, enabling broadband photoresponse across the entire mid-infrared spectrum. This approach allows real-time, spectrally non-selective sensing of various molecules. *Bolometric effect: A principle where absorbed light increases the local temperature of a material, which in turn changes in the material’s electrical resistance.

The room-temperature, CMOS-compatible waveguide-integrated mid-infrared photodetector developed by SangHyeon Kim’s research team addresses key limitations of existing technologies—particularly the reliance on cooling systems, limited scalability, and high manufacturing costs.

〈 Figure 2. Room-temperature photoresponse characteristics (left) and real-time CO₂ gas sensing results (right) using the fabricated waveguide-integrated photodetector 〉

This technology is expected to find broad applications in areas such as environmental monitoring, industrial process control, medical diagnostics, defense and security, and smart sensing platforms. It provides a crucial technological foundation for the next generation of mid-infrared sensor systems.

Prof. SangHyeon Kim stated, “This research presents a novel approach that overcomes the limitations of existing mid-infrared photodetector technologies and offers significant potential for practical applications across a wide range of fields.” He added, “Thanks to its compatibility with CMOS processes, this sensor can be mass-produced at low cost and will be highly useful in next-generation environmental monitoring systems and smart manufacturing environments.”

〈 Figure 3. Performance comparison of waveguide-integrated photodetectors using bolometric effect. Our approach can cover the entire mid-infrared spectrum for spectroscopic analysis of numerous biochemical molecules. 〉

This research was published on March 19, 2025, in the prestigious international journal Light: Science & Applications (JCR top 2.9%, IF = 20.6). The first author is Dr. Joonsup Shim, currently a postdoctoral researcher at Harvard University. (Paper title: Room-temperature waveguide-integrated photodetector using bolometric effect for mid-infrared spectroscopy applications, DOI: https://doi.org/10.1038/s41377-025-01803-3)

This work was supported by the National Research Foundation (NRF) of Korea.

Archives: 연구 > 연구성과

Professor Hyun Myung’s Team Wins First Place at Prestigious International Robotics Conference Challenge

SID 2025 Distinguished Student Paper Award and Young Leadership Conference Selection, Hyejeong Yeon, Ph.D. Candidate from Prof. Kyung Cheol Choi’s Lab (ADNC Lab)

EE Prof. Ian Oakley’s Research Team Develops Next-Generation Wearable Interaction Technologies Using Around-Device Sensing

EE Prof. Sanghyeon Kim’s Lab Selected for Samsung Research Funding & Incubation Center for Future Technology’s New Project for the First Half of 2025

EE Professors Myoungsoo Jung, John Kim, Song Min Kim, Minsoo Rhu Awarded National R&D Grant for The Large-Scale Silicon Project under the ‘K-Cloud Technology Development Program’

EE Prof. Sung-Ju Lee Unveils AI Songwriting Companion ‘Amuse’ to Support Music Creation

Prof. Shinhyun Choi Selected as Winner of the Hyeon-Woo KAIST Scholastic Award

Prof. Hyeonmin Bae Awarded KAIST Research Grand Prize at 2025 Research Day

EE Professor Hyunchul Shim’s Team Wins 3rd Place at A2RL Autonomous Drone Racing Competition

EE Prof. SangHyeon Kim’s Team Develops Room-Temperature Waveguide-integrated Mid-Infrared Photodetector with CMOS-Compatible Solution

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