https://scholar.dgist.ac.kr/handle/20.500.11750/815 2026-11-11T11:27:19Z 2026-11-11T11:27:19Z Dhanasekaran, Thangavelu Kumar, Ponnaiah Sathish Kim, Young-Ki Jeyaprabha, Balasubramanian Lee, Sungwon Kim, Kibum https://scholar.dgist.ac.kr/handle/20.500.11750/61077 2026-11-03T05:40:18Z 2026-08-31T15:00:00Z

Title: MOF and MXene-derived atom-level catalysts (Fe, co and Ni): Trends, breakthroughs, and challenges in water splitting Author(s): Dhanasekaran, Thangavelu; Kumar, Ponnaiah Sathish; Kim, Young-Ki; Jeyaprabha, Balasubramanian; Lee, Sungwon; Kim, Kibum Abstract: Developing efficient and cost-effective catalysts for industrial-scale hydrogen (H2) and oxygen (O2) production is crucial for the clean energy transition. Atomically dispersed single-atom catalysts (AD SACs) (e.g., iron (Fe), cobalt (Co), and nickel (Ni)) without precious metals are particularly promising, offering 100% atomic utilization and optimum catalytic efficiency. Nonetheless, key challenges remain, including the suppression of atom aggregation, the optimization of support structures, and the maintenance of stability. Moreover, industrial catalysis demonstrates that active components with suitable supports are critical, and catalytic efficacy often increases as the size of the active components decreases, opening new frontiers in catalyst design. Thus, metal-organic frameworks (MOFs) and MXenes have emerged as effective anchoring matrices, enabling modulation of electronic structures, rapid charge transfer, and enhanced stabilization of single metal atoms. This review highlights recent progress in the development of AD SACs anchored on MOFs and MXenes, emphasizing the fundamental parameters governing hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance. Furthermore, we integrate theoretical insights from Density Functional Theory (DFT) with advanced operando and in-situ characterization techniques to provide a comprehensive understanding of the mechanistic origins governing HER/OER activity. We anticipate that these insights will contribute to improving water-splitting efficiency and sustainability, which are vital for advancing the clean energy revolution. Finally, this review outlines future directions for the development of high-efficiency, cost-effective MXene-and MOF-based SAC catalysts, underscoring their potential in clean energy production.

2026-08-31T15:00:00Z Choi, Hyeokjoo Shin, Juhee Bae, Jihoon Lee, Seungyeop Hwang, Sieun Jang, Gain Mun, Seul-Ah Kim, Chi Heon Han, Inbo Roh, Jong Wook Kim, Kyoung-Tae Lee, Sungwon https://scholar.dgist.ac.kr/handle/20.500.11750/60689 2026-08-31T06:40:14Z 2026-04-30T15:00:00Z

Title: Tissue-Adaptive, Adhesive, and Ultra-Conformal Polymer Nanomesh-Based Implantable Bioelectrode for Long-Term Stable Electrical Stimulation Author(s): Choi, Hyeokjoo; Shin, Juhee; Bae, Jihoon; Lee, Seungyeop; Hwang, Sieun; Jang, Gain; Mun, Seul-Ah; Kim, Chi Heon; Han, Inbo; Roh, Jong Wook; Kim, Kyoung-Tae; Lee, Sungwon Abstract: Electrical stimulation has emerged as a promising strategy for enhancing bone regeneration; however, its long-term effectiveness is often limited by poor electrode-tissue conformity, mechanical mismatch, and interfacial instability in the complex and heterogeneous bone environment. Here, we present a tissue-adaptive, ultra-conformal polymer nanomesh-based implantable bioelectrode designed to enable stable and reliable electrical stimulation on mechanically rigid and topographically irregular bone surfaces. Nanomesh-based bioelectrodes demonstrated superior mechanical compliance and tissue adaptability, with smaller changes in dermal (polyimide film: 1192.26 & micro;m, nanomesh: 905.56 & micro;m) and fibrotic thickness (polyimide film: 240 & micro;m, nanomesh: 49.04 & micro;m) after eight weeks of implantation. The porous nanomesh structure exhibited 2.9- and 7.3-times improved adhesive properties for sliding and peel-off, respectively. Additionally, its porosity promoted tissue growth, enhancing adhesion, mechanical compliance, and stable long-term electrical energy transfer. Finally, in a rabbit calvaria bone defect model, the nanomesh-based electroceutical system enhanced bone mineral density by 15% and bone volume by 25% compared to the control group. This work highlights the potential of nanomesh-based implantable bioelectrode as a platform for effective, long-term tissue regeneration.

2026-04-30T15:00:00Z Choi, Hyeokjoo Lee, Dongju Hwang, Sieun Shin, Juhee Bae, Jihoon Jang, Gain Kwon, Seokhun Kang, Hyunil Myeong, Jihyeon Jeong, Youngtae Roh, Jong Wook Lee, Sungwon https://scholar.dgist.ac.kr/handle/20.500.11750/59285 2026-01-16T01:10:11Z 2025-11-30T15:00:00Z

Title: Ultra-thin high-resolution transfer-printed breathable electronics for conformal wearable devices Author(s): Choi, Hyeokjoo; Lee, Dongju; Hwang, Sieun; Shin, Juhee; Bae, Jihoon; Jang, Gain; Kwon, Seokhun; Kang, Hyunil; Myeong, Jihyeon; Jeong, Youngtae; Roh, Jong Wook; Lee, Sungwon Abstract: Nanomesh electronics offer remarkable potential for biomedical and human–machine interface applications due to their conformability to nonplanar surfaces, versatile functionality, and long-term reliability. However, existing materials face significant challenges related to surface structure and chemical resistance, resulting in high electrical resistance and complex fabrication requirements. To address these challenges, we present transfer-printed nanomesh electrodes (NEs) produced by integrating fine-patterned 2D electrodes with porous nanomesh. Electrospun thermoplastic-polyurethane nanofibers provide strong adhesion to the electrodes, which generate sufficient force (95.1 mN∙cm−1) to maintain structural integrity and electrical performance. Unlike direct deposition, which requires a minimum thickness of 100nm to achieve 14.12±2 mS, transfer-printed NEs reach 16.91±8.7 mS only with 20nm. Furthermore, our electrodes demonstrate excellent durability under deformation, maintaining stable electrical performance with only a 0.53% change at a bending radius of 1mm. To validate their practical application, we demonstrate a NE-based tactile sensor, which exhibits a conductance change from 0 mS in the normal state to 130 mS upon touch. These results highlight the potential of transfer-printed NEs for next-generation e-skin with fine patterning, high conductivity, and long-term reliability. In addition, our novel method addresses the challenges of manufacturing breathable devices with functionalities extending beyond simple electrodes.

2025-11-30T15:00:00Z Kwon, Seokhun Choi, Hyeokjoo Kim, Chulsoo Shin, Juhee Kim, Kangmin Noh, Jihwan Eo, Sungwoo Lee, Seokwon Hwang, Hyunsuk Lee, Sungwon Kang, Hyunil https://scholar.dgist.ac.kr/handle/20.500.11750/59035 2025-12-03T13:40:14Z 2025-11-30T15:00:00Z

Title: Robust, Stretchable, and Flexible Polymer Nanofiber-Based Wearable Platform for Colorimetric and Chemiresistive Dual-Mode Ammonia Gas Sensing Author(s): Kwon, Seokhun; Choi, Hyeokjoo; Kim, Chulsoo; Shin, Juhee; Kim, Kangmin; Noh, Jihwan; Eo, Sungwoo; Lee, Seokwon; Hwang, Hyunsuk; Lee, Sungwon; Kang, Hyunil Abstract: Ammonia (NH3) is the second-most-produced chemical worldwide and has numerous industrial applications. However, such applications pose significant risks, as evidenced by human casualties caused by NH3 leaks or poisoning in confined environments. This highlights the critical need for highly portable and intuitive wearable NH3 sensors. The chemiresistive sensors are widely employed in wearable devices due to their simple structure, high sensitivity, and short response times, but are prone to malfunctioning and inaccurate gas detection because of the corrosion or failure of the sensing material under the influence of humidity, high temperatures, and interfering gas species. Addressing these limitations, a gas-sensing platform with a polymer-based nanofiber structure has been developed, providing flexibility and facilitating efficient transport of NH3 between the colorimetric (bromocresol-green-based) and chemiresistive (poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate)-based) sensing layers. This dual-mode design enables reliable NH3 detection. The NH3-sensing performance of each individual layer is comparable to that of the dual-mode gas-sensing platform, which operates effectively even when attached to human skin and in humid environments. Therefore, this study establishes a robust, selective, and reproducible NH3 sensor for diverse applications and introduces an innovative sensor engineering paradigm.

2025-11-30T15:00:00Z