https://scholar.dgist.ac.kr/handle/20.500.11750/174 2026-04-04T08:09:19Z 2026-04-04T08:09:19Z Lee, Hakjoon Gharamaleki, Nader Latifi Choi, Hongsoo https://scholar.dgist.ac.kr/handle/20.500.11750/60062 2026-02-26T08:40:11Z 2025-05-18T15:00:00Z

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 Li, Tingyu Liu, Yaoping Lin, Lianjun Kim, Eun Hee Liu, Xinmin Li, Haichao Choi, Hongsoo Wang, Wei https://scholar.dgist.ac.kr/handle/20.500.11750/58673 2025-07-25T04:10:18Z 2018-11-10T15:00:00Z

Title: Cell block preparation from pleural fluid by an ultrasound-assisted filtration Author(s): Li, Tingyu; Liu, Yaoping; Lin, Lianjun; Kim, Eun Hee; Liu, Xinmin; Li, Haichao; Choi, Hongsoo; Wang, Wei Abstract: This paper reports a novel ultrasound-assisted filtration technique for cell block (CB) preparation from pleural fluid. CB (> 5×106 cells) from a large-volume (>10 mL) specimen was obtained on the Parylene-C filtration membrane (1.29×106 micropores) with a high recovery rate (>90%), a high cell viability (>96%) and an effective depletion of red blood cells (RBCs). The prepared CB of A549s (cultured lung cancer cells) from PBS and target cells from clinical pleural fluid can be well embedded with paraffin. Successful hematoxylin-eosin (HE), immunocytochemistry (ICC) and immunofluorescence (IF) staining of the CBs sections were demonstrated, showing the promise of application in clinical practices. Copyright © (2018) by Chemical and Biological Microsystems Society. All rights reserved.

2018-11-10T15:00:00Z Jin, Chaewon Choi, Hongsoo Kim, Jin-Young https://scholar.dgist.ac.kr/handle/20.500.11750/58670 2025-07-25T03:22:17Z 2021-10-10T15:00:00Z

Title: 96-WELL FORMAT-BASED MICROFLUIDIC PLATFORM FOR HIGH-THROUGHPUT DRUG SCREENING Author(s): Jin, Chaewon; Choi, Hongsoo; Kim, Jin-Young Abstract: In this study, a simple and robust microfluidic platform is presented, which can interconnect and culture multiple microtissues (MTs) as 96-well format-based platform. Human colon cancer (HCT116) MTs were cultured over 4 days and exposed to various concentrations of endoxifen. Drug resistance was observed when HCT116 MTs were cultured under perfusion conditions. It addresses the feasibility of our microfluidic platform for more complex and comprehensive pharmacokinetic study in an in vivo-like in vitro physiological environment. © 2021 MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.

2021-10-10T15:00:00Z Jeon, Sang Hun Lee, Ji Eun Kim, Eunhee Kim, Jin-Young Choi, Hongsoo https://scholar.dgist.ac.kr/handle/20.500.11750/57874 2025-07-25T03:33:06Z 2017-03-31T15:00:00Z

Title: Microrobots for precise drug delivery using nano-particles Author(s): Jeon, Sang Hun; Lee, Ji Eun; Kim, Eunhee; Kim, Jin-Young; Choi, Hongsoo

2017-03-31T15:00:00Z