https://scholar.dgist.ac.kr/handle/20.500.11750/16350 2026-06-24T04:28:14Z 2026-06-24T04:28:14Z Park, Jun Hyun Park, Jae Woo Choi, Min Seok Pang, Sang Uk Choe, Jun Seok Yu, Tae Sang Jang, Kyung-In Kim, Jin-Tae Chung, Ha Uk Kim, Jang Hwan Kim, Bong Hoon https://scholar.dgist.ac.kr/handle/20.500.11750/60417 2026-06-15T18:01:16Z 2026-02-28T15:00:00Z

Title: Multifunctional Sweat Sensors Using Semiconductor Fibers Based on Two-Dimensional Nanomaterials Author(s): Park, Jun Hyun; Park, Jae Woo; Choi, Min Seok; Pang, Sang Uk; Choe, Jun Seok; Yu, Tae Sang; Jang, Kyung-In; Kim, Jin-Tae; Chung, Ha Uk; Kim, Jang Hwan; Kim, Bong Hoon Abstract: Sweat monitoring offers real-time insights into physiological conditions such as hydration, muscle fatigue, and metabolic status. However, conventional sweat sensors often face challenges associated with unstable skin contact and insufficient sampling. In this study, a fiber-based wearable sensing platform is proposed, which incorporates semiconducting molybdenum disulfide (MoS2) and polylactic acid (PLA) composite fibers fabricated via wet spinning. By exploiting the high surface-to-volume ratio and n-type semiconducting nature of the MoS2 network, the sensor selectively detects major biomarkers including electrolytes (Na+ and K+) and metabolites (lactic acid and NH4+) via distinct electrostatic screening and charge trapping mechanisms. Furthermore, the intrinsic capillary action and thermal insulation of the fibers ensured reliable sweat collection without the requirement for external power. Additionally, the composite fiber exhibits piezoresistive capabilities, enabling simultaneous pressure monitoring to track physical motion. Multifunctional sensing facilitates the early diagnosis of metabolic disorders and the precise tracking of athletic performance. The developed fiber-based sensor provides a robust textile-integrated solution for next-generation personalized healthcare monitoring. © 2026 The Author(s). Small Structures published by Wiley-VCH GmbH.

2026-02-28T15:00:00Z Park, Jun Hyun Jin, Ho Jun Kim, Simon Lee, Su Eon Ko, Young-chun Kim, Jang-hwan Kim, Bong Hoon https://scholar.dgist.ac.kr/handle/20.500.11750/60214 2026-04-15T18:01:43Z 2026-01-31T15:00:00Z

Title: Advanced frugal methodology for accessible precision materials processing and characterization Author(s): Park, Jun Hyun; Jin, Ho Jun; Kim, Simon; Lee, Su Eon; Ko, Young-chun; Kim, Jang-hwan; Kim, Bong Hoon Abstract: Frugal science offers transformative potential by democratizing access to scientific research through the replacement of specialized, high-cost laboratory instruments with accessible, low-cost alternatives. In this study, we introduce three universal advanced frugal toolkit that enable the cost-effective validation of experimental concepts across diverse engineering disciplines. We demonstrate that a repurposed household fan motor functions as an effective spin-coater substitute, exhibiting angular velocity stability that yields thin films with uniformity and morphology comparable to commercial systems. Furthermore, we establish that a common tack can be employed for nanoindentation to induce reproducible localized plastic deformation, facilitating the reliable comparative assessment of surface mechanical properties. Additionally, we show that diamond cutter-scribed guide trenches on silicon substrates successfully direct the graphoepitaxy of block copolymers, producing highly ordered nanopatterns comparable to those achieved by advanced EUV lithography. These accessible advanced frugal methods preserve critical performance characteristics while significantly lowering financial and logistical barriers, thereby supporting rapid prototyping, risk-averse decision-making, and inclusive innovation in both resource-limited and well-funded research environments.

2026-01-31T15:00:00Z Jo, Seong-Jun Jin, Ho Jun Lee, Jae Gyeong Wie, Jeong Jae Kim, Bong Hoon Kim, Jaehwan https://scholar.dgist.ac.kr/handle/20.500.11750/59374 2026-04-30T07:10:17Z 2026-01-31T15:00:00Z

Title: Advances in skeletal muscle-inspired actuation using functional stimuli-responsive materials Author(s): Jo, Seong-Jun; Jin, Ho Jun; Lee, Jae Gyeong; Wie, Jeong Jae; Kim, Bong Hoon; Kim, Jaehwan Abstract: Skeletal muscles are fundamental biological systems that convert biochemical energy into mechanical work, enabling movement, force generation, and multifunctional tasks such as self-sensing and adaptive control. Artificial muscles based on stimuli-responsive materials have been developed to replicate these versatile functions. This review reorganizes existing literature from the perspective of skeletal-muscle mimetics by outlining three representative actuation strategies. The first involves contractile or extensional actuation that mirrors sarcomere motion. The second focuses on bending or twisting actuators that reproduce joint motions or localized muscle bending. The third highlights coiled fiber structures that directly imitate fascicles, reproducing both the motion and functional performance of the skeletal muscle. For each category, the advantages, limitations, and distinctive features of various material systems are summarized. In addition, representative studies are highlighted to demonstrate how these materials have been engineered to achieve skeletal-muscle-like performance. Beyond motion replication, advanced strategies are discussed that aim to realize realistic skeletal-muscle functions, including the integration of multi-stimuli-responsive materials and use of structural constraints to enable complex multimodal actuation. These material- and structure-level strategies are designed to be complementary, working synergistically to achieve more lifelike skeletal-muscle behavior. Finally, an outlook is provided on future research directions, with emphasis on material innovations, multifunctional integration, and adaptive design principles that support the transition from stimuli-responsive actuators to practical applications in soft robotics, wearable systems, and biomedical devices.

2026-01-31T15:00:00Z Park, Jae Chul Kim, Jang Hwan Kim, Hojun Kim, Bong Hoon https://scholar.dgist.ac.kr/handle/20.500.11750/59358 2026-02-24T05:40:11Z 2025-11-30T15:00:00Z

Title: When bubble meets sludge Author(s): Park, Jae Chul; Kim, Jang Hwan; Kim, Hojun; Kim, Bong Hoon Abstract: Piezoelectric ultrasound transducers generate transient cavitation that removes persistent fouling from mesh filters within seconds. This strategy enables stable, ultrahigh-flux wastewater treatment while substantially reducing energy demands.

2025-11-30T15:00:00Z