https://scholar.dgist.ac.kr/handle/20.500.11750/155 Department of Robotics and Mechatronics Engineering, DGIST 2026-08-17T00:47:37Z https://scholar.dgist.ac.kr/handle/20.500.11750/60614 Title: Nut-Driven Transmission Force Controllable Motion Platform for Suppressing Low-Frequency and Impulsive Base Disturbances Author(s): Cheon, Dasol; Oh, Sehoon Abstract: This article proposes a transmission-force controllable actuator (TFCA) for vibration suppression in linear motion platforms. Unlike conventional screw-driven systems, the nut-driven TFCA integrates a compliant spring and encoder to measure and control the transmission force in real time, thereby reducing reflected inertia, increasing stiffness, and enabling rapid response to external disturbances. Dynamic models were derived, and two control strategies-acceleration-based vibration suppression control (AVSC) and transmission-force and ACSC (TAVSC)-were implemented. Experiments using a base-shaker setup evaluated three scenarios: back-drivability, impulse disturbance, and multisine excitation (0.1-100 Hz). Results show that TAVSC reduced acceleration and jerk by over 50% in the time domain and achieved more than 90% suppression in the 0.5-8 Hz band, while AVSC exhibited only marginal improvement. Under multisine excitation, TAVSC maintained more than 5 dB suppression across the spectrum and 86% reduction in the 0.5-8 Hz band. These findings confirm that transmission-force feedback substantially improves vibration suppression against impulsive and low-frequency base disturbances, demonstrating the potential of TFCA for applications such as ambulance stretchers and human-sensitive transport systems. 2026-08-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/60611 Title: 96-Well Format-Based Liver–Heart-on-a-Chip Platform for Facile and Parallel Testing of Drug-Induced Cardiotoxicity after Liver Metabolism Author(s): Lee, Sebeen; Jin, Chaewon; Choi, Hongsoo; Kim, Jin-young Abstract: Current preclinical drug evaluation predominantly relies on conventional two-dimensional (2D) cell cultures grown in static environments, which lack dynamic interactions and fail to recapitulate complex microenvironments. These approaches are inefficient and overly simplistic, and often require costly animal models that poorly mimic human physiology. Body-on-a-chip (BoC) technology─comprising robust and flexible three-dimensional (3D) microtissues (MTs)─has emerged to address these limitations. BoC platforms constitute microphysiological systems that mimic human organ physiology and function in vitro, enabling improved toxicity screening and personalized medicine. Here, we present a 96–well format-based microfluidic liver–heart-on-a-chip platform that supports parallel, gravity-driven perfusion to efficiently predict and assess multiorgan drug effects. We demonstrate hepatic metabolism of the cardiotoxic prodrug terfenadine (TFND) into its noncardiotoxic metabolite fexofenadine within liver MTs and the consequent physiological–pathological responses of cardiac MTs. The optimized liver–heart-on-a-chip preserves multitissue functionality, underscores the importance of continuous media circulation, and reveals intertissue interactions relevant to drug-induced cardiotoxicity after liver metabolism. 2026-02-28T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/60599 Title: Harvesting energy from friction: the revolutionary decade of triboelectric nanogenerators Author(s): Khanapurarm, Uday Kumar; Rani, Gokana Mohana; Panda Swati; Charoonsuk, Thitirat; Mistewicz, Krystian; Hajra, Sugato; Kaja, Kushal Ruthvik; Umapathi, Reddicherla; Sriphan, Saichon; Jała, Jakub; Divi, Haranath; Smalcerz, Albert; Belal, Mohamed; Jaahnavi, Pannur; Safarkhani, Moein; Kim, Hanseung; Mishra, Yogendra Kumar; Kim, Hoe Joon; Huh, Yun Suk; Vittayakorn, Naratip; Nowacki, Bartłomiej; Ravi, Sai Kishore; Eichhorn, Stephen James; Craciun, Monica F.; Borras, Ana; Khanbareh, Hamideh; Qin, Jiaqian; Rajaboina, Rakesh Kumar Abstract: Triboelectric nanogenerators (TENGs) have rapidly developed into a transformative energy harvesting technology, enabling self-powered, sustainable electronic systems. This review offers the first comprehensive, multidisciplinary perspective that connects the physics of triboelectric charge transfer with material innovation, device engineering, and real-world applications. We systematically categorize and measure the triboelectric series across a wide range of materials, including polymers, 2D materials, MOFs, perovskites, cellulose, and biodegradable frameworks, using experimentally validated methods. In addition to traditional approaches, this work highlights emerging strategies such as machine learning-guided material discovery, 3D printing, and advanced structural engineering to improve charge retention, durability, and power output. Unlike existing reviews, it uniquely combines theory and application insights, presents diverse uses from biomedical sensing and environmental monitoring to underwater communication and mechanoluminescence, and outlines a forward-looking plan for sustainable energy harvesting. This comprehensive synthesis serves as an essential resource for researchers and technologists designing next-generation TENGs and multifunctional self-powered devices. 2026-03-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/60594 Title: Viola seed pod architecture shapes sequential, force-augmented pinching Author(s): Kim, Cheongsan; Won, Jihyun; Kim, Donghyeon; Jung, Sohyun; Kim, Ho-Young; Hyun, Youbong Abstract: Many plants explosively launch seeds, but these natural catapults often display inefficient, unpredictable energy transfer in seed ejection. Violets (Viola spp.) address this problem by ejecting seeds successively with consistent propulsive force from a single pod, a strategy that requires sophisticated energy release. In this work, we show that Viola achieves this feat with a simple and compact structure that generates adaptive force augmentation through sequential pinching. Our biological and mathematical analyses indicate that the pod valve's morphogeometry optimizes pinching with sufficient strength for seed ejection with limited material cost and creates a shifting force-amplifying hotspot, which allows consecutive seed ejections. We use this design principle to create autonomous zipping actuators for a range of applications, including biomedical soft machines. 2026-05-31T15:00:00Z