https://scholar.dgist.ac.kr/handle/20.500.11750/171 2026-04-24T14:10:30Z https://scholar.dgist.ac.kr/handle/20.500.11750/60229 Title: A magnetically steerable soft gripper for navigating and grasping in constrained spaces Author(s): Dong Xiao; Lee, Hakjoon; Ahmed, Awais; Choi, Hongsoo Abstract: Magnetic soft grippers hold significant promise for applications requiring gentle and soft interaction with objects. However, steering their movement within constrained spaces remains a major challenge. This study presents a magnetically steerable soft gripper that combines a magnetically steerable soft tube with a magnetic soft gripper. By utilizing distinct magnetization directions for the soft gripper and soft tube, both steering and gripping can be achieved through an external magnetic field. The gripper is capable of lifting objects weighing more than 68 times its own weight under a 40 mT magnetic field (1.7 times per mT). It can also grasp objects of various shapes and sizes. When integrated with a commercial catheter, the steerable gripper successfully performs targeted gripping in a 3D phantom environment. This work introduces a novel magnetically steerable soft gripper system for precise manipulation in confined spaces, with strong potential for applications inside the human body. © The Korean Society of Mechanical Engineers and Springer-Verlag GmbH Germany, part of Springer Nature 2026. 2025-12-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/60217 Title: Magnetic hyperthermia-induced hydrogen therapy for cancer treatment using PEG-coated Mg–Ni Degradable microrobots Author(s): Dutta, Sourav; Patra, Tanushree; Yea, Kyungmoo; Choi, Hongsoo Abstract: Hydrogen therapy using magnesium-based micromotors offers a promising strategy for treating diseases such as cancer, diabetes, and Alzheimer’s, which are associated with elevated levels of reactive oxygen species (ROS). However, their clinical application is limited by uncontrollable motion and high reactivity in physiological environments. To overcome these challenges, we have developed a polymer-coated, magnetically guided magnesium (Mg) microrobot that integrates hydrogen therapy with magnetic hyperthermia. The polymer coating ensures stability in phosphate-buffered saline (PBS), while the microrobot achieves a velocity of 18.63 ± 0.85 μm/s under a 15 mT, 10 Hz rotating magnetic field. Mild magnetic heating (∼43 °C) partially melts the polymeric shell, triggering hydrogen release. In vitro studies with HCT 116 cells demonstrated a significant reduction in ROS at 3 mg/mL following magnetic hyperthermia. In vivo experiments in mice showed that the microrobot alleviated oxidative stress and significantly decreased tumor volume. These results indicated that Mg-based microrobots represent a controllable and effective therapeutic platform for ROS-related diseases. © 2026 . 2026-01-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/60062 Title: Open-Loop Position Control of a Miniature Magnetic Robot Using Two-Dimensional Divergence Control of a Magnetic Force Author(s): Lee, Hakjoon; Gharamaleki, Nader Latifi; Choi, Hongsoo Abstract: Miniature magnetic robots have attracted considerable attention as promising tools in biomedical applications due to their wireless actuation and precise controllability in a minimally invasive manner. Traditionally, magnetic microrobots have been controlled by globally applied magnetic torques and forces generated by external magnetic actuation systems (MASs), which typically require closed-loop control with real-time vision tracking - a challenging requirement in in-vivo environments. To address this issue, this paper suggests a novel open-loop control scheme for magnetic robots, using two-dimensional (2D) divergence control of a magnetic force generated by stationary electromagnets. Constraint equations for the currents applied to the electromagnets were established to achieve 2D divergence control of a magnetic force. Numerical simulation and experimental validations demonstrate that this approach can generate sufficient magnetic forces that either converge at or diverge from a target point, enabling effective open-loop position control of a miniature magnetic robot. Due to the absence of vision feedback and mechanical motions of magnets, the proposed control strategy could be more clinically applicable for medical applications of magnetic robots. 2025-05-18T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59929 Title: Translational reprogramming of dentate gyrus peptidergic circuitry gates antidepressant efficacy Author(s): Seo-Jin Oh; Jin-jyeok Jang; Jean-Pierre Roussarie; Gyeong-un Jang; Min-seok Jeong; Yeon Suk Jo; Chang-Hoon Shin; Hongsoo Choi; Kwang Lee; Yoon, Jong-Hyeok; Yong-Seok Oh Abstract: Selective serotonin reuptake inhibitors (SSRIs) exhibit delayed therapeutic effects despite rapid serotonin elevation, suggesting their dependence on slow neuroplastic adaptations. Here, we demonstrate that antidepressant actions require cell type-specific translational regulation of the peptidergic signaling in the dentate gyrus (DG). Chronic, but not acute, treatment with an SSRI fluoxetine (FLX) selectively enhances translational activity in hilar mossy cells (MCs), with no detectable changes in neighboring granule cells (GCs). Combining Translating Ribosome Affinity Purification (TRAP) with RNA sequencing revealed distinct baseline translatomes between these two glutamatergic neurons and identified FLX-induced remodeling of peptidergic pathways in the DG. Crucially, we discovered MC-specific enrichment of the neuropeptide PACAP, which undergoes translation-dependent upregulation by chronic FLX treatment. This PACAP induction mediates neuroadaptive plasticity in PAC1 receptor-expressing GCs and drives behavioral responses prominently in female mice during prolonged FLX administration. Our findings establish cell type-specific translational reprogramming as a novel mechanistic framework for antidepressant action.