Search

Your search keyword '"Choi, Hongsoo"' showing total 380 results
Start Over "Choi, Hongsoo"
380 results on '"Choi, Hongsoo"'

4. Strain sensitive flexible magnetoelectric ceramic nanocomposites

Author

Kim, Minsoo, Kim, Donghoon, Aktas, Buse, Choi, Hongsoo, Puigmartí-Luis, Josep, Nelson, Bradley J., Chen, Xiang-Zhong, and Pané, Salvador

Subjects
Physics - Applied Physics, Condensed Matter - Materials Science
Abstract

Advanced flexible electronics and soft robotics require the development and implementation of flexible functional materials. Magnetoelectric (ME) oxide materials can convert magnetic input into electric output and vice versa, making them excellent candidates for advanced sensing, actuating, data storage, and communication. However, their application has been limited to rigid devices due to their brittle nature. Here, we report flexible ME oxide composite (BaTiO3/CoFe2O4) thin film nanostructures that can be transferred onto a stretchable substrate such as polydimethylsiloxane (PDMS). In contrast to rigid bulk counterparts, these ceramic nanostructures display a flexible behavior and exhibit reversibly tunable ME coupling via mechanical stretching. We believe our study can open up new avenues for integrating ceramic ME composites into flexible electronics and soft robotic devices.

Published
2022
Full Text
View/download PDF

6. Giant shape-memory effect in twisted ferroic nanocomposites

Author

Kim, Donghoon, Kim, Minsoo, Reidt, Steffen, Han, Hyeon, Choi, Hongsoo, Puigmartí-Luis, Josep, Trassin, Morgan, Nelson, Bradley J., Chen, Xiang-Zhong, and Pané, Salvador

Subjects
Condensed Matter - Materials Science
Abstract

The shape recovery ability of shape-memory alloys vanishes below a critical size (~50nm), which prevents their practical applications at the nanoscale. In contrast, ferroic materials, even when scaled down to dimensions of a few nanometers, exhibit actuation strain through domain switching, though the generated strain is modest (~1%). Here, we develop free-standing twisted architectures of nanoscale ferroic oxides showing shape-memory effect with a giant recoverable strain (>10%). The twisted geometrical design amplifies the strain generated during ferroelectric domain switching, which cannot be achieved in bulk ceramics or substrate-bonded thin films. The twisted ferroic nanocomposites allow us to overcome the size limitations in traditional shape-memory alloys and opens new avenues in engineering large-stroke shape-memory materials for small-scale actuating devices such as nanorobots and artificial muscle fibrils.

Published
2022
Full Text
View/download PDF

14. Frequency‐Selective, Multi‐Channel, Self‐Powered Artificial Basilar Membrane Sensor with a Spiral Shape and 24 Critical Bands Inspired by the Human Cochlea.

Author

Jeon, Eun‐Seok, Lee, Useung, Yoon, Seongho, Hur, Shin, Choi, Hongsoo, and Han, Chang‐Soo

Subjects
BASILAR membrane, ARTIFICIAL membranes, COCHLEA, POLYIMIDE films, PIEZOELECTRIC detectors, COCHLEA physiology
Abstract

A spiral‐artificial basilar membrane (S‐ABM) sensor is reported that mimics the basilar membrane (BM) of the human cochlea and can detect sound by separating it into 24 sensing channels based on the frequency band. For this, an analytical function is proposed to design the width of the BM so that the frequency bands are linearly located along the length of the BM. To fabricate the S‐ABM sensor, a spiral‐shaped polyimide film is used as a vibrating membrane, with maximum displacement at locations corresponding to specific frequency bands of sound, and attach piezoelectric sensor modules made of poly(vinylidene fluoride‐trifluoroethylene) film on top of the polyimide film to measure the vibration amplitude at each channel location. As the result, the S‐ABM sensor implements a characteristic frequency band of 96‐12,821 Hz and 24‐independent critical bands. Using real‐time signals from discriminate channels, it is demonstrated that the sensor can rapidly identify the operational noises from equipment processes as well as vehicle sounds from environmental noises on the road. The sensor can be used in a variety of applications, including speech recognition, dangerous situation recognition, hearing aids, and cochlear implants, and more. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

24. Design and Synthesis of CdHgSe/HgS/CdZnS Core/Multi‐Shell Quantum Dots Exhibiting High‐Quantum‐Yield Tissue‐Penetrating Shortwave Infrared Luminescence

Author

Lee, Gyudong, primary, Jeong, Woo Hyeon, additional, Kim, Beomjoo, additional, Jeon, Sungwoong, additional, Smith, Andrew M., additional, Seo, Jongcheol, additional, Suzuki, Kengo, additional, Kim, Jin‐young, additional, Lee, Hyunki, additional, Choi, Hongsoo, additional, Chung, Dae Sung, additional, Choi, Jongmin, additional, Choi, Hyosung, additional, and Lim, Sung Jun, additional

Published
2023
Full Text
View/download PDF

25. 3D Printed Template‐Assisted Casting of Biocompatible Polyvinyl Alcohol‐Based Soft Microswimmers with Tunable Stability

Author

Sanchis‐Gual, Roger, primary, Ye, Hao, additional, Ueno, Towa, additional, Landers, Fabian C., additional, Hertle, Lukas, additional, Deng, Siyu, additional, Veciana, Andrea, additional, Xia, Yanming, additional, Franco, Carlos, additional, Choi, Hongsoo, additional, Puigmartí‐Luis, Josep, additional, Nelson, Bradley J., additional, Chen, Xiang‐Zhong, additional, and Pané, Salvador, additional

Published
2023
Full Text
View/download PDF

28. Stretchable and suturable fibre sensors for wireless monitoring of connective tissue strain

Author

Lee, Jaehong, Ihle, Stephan J., Pellegrino, Guglielmo Salvatore, Kim, Hwajoong, Yea, Junwoo, Jeon, Chang-Yeop, Son, Hee-Chang, Jin, Chaewon, Eberli, Daniel, Schmid, Florian, Zambrano, Byron Llerena, Renz, Aline F., Forró, Csaba, Choi, Hongsoo, Jang, Kyung-In, Küng, Roland, Vörös, Janos, Lee, Jaehong, Ihle, Stephan J., Pellegrino, Guglielmo Salvatore, Kim, Hwajoong, Yea, Junwoo, Jeon, Chang-Yeop, Son, Hee-Chang, Jin, Chaewon, Eberli, Daniel, Schmid, Florian, Zambrano, Byron Llerena, Renz, Aline F., Forró, Csaba, Choi, Hongsoo, Jang, Kyung-In, Küng, Roland, and Vörös, Janos

Abstract

Implantable sensors can be used to monitor biomechanical strain continuously. However, three key challenges need to be addressed before they can be of use in clinical practice: the structural mismatch between the sensors and tissue or organs should be eliminated; a practical suturing attachment process should be developed; and the sensors should be equipped with wireless readout. Here, we report a wireless and suturable fibre strain-sensing system created by combining a capacitive fibre strain sensor with an inductive coil for wireless readout. The sensor is composed of two stretchable conductive fibres organized in a double helical structure with an empty core, and has a sensitivity of around 12. Mathematical analysis and simulation of the sensor can effectively predict its capacitive response and can be used to modulate performance according to the intended application. To illustrate the capabilities of the system, we use it to perform strain measurements on the Achilles tendon and knee ligament in an ex vivo and in vivo porcine leg.

Published
2023

30. Recent Developments in Metallic Degradable Micromotors for Biomedical and Environmental Remediation Applications.

Author

Dutta, Sourav, Noh, Seungmin, Gual, Roger Sanchis, Chen, Xiangzhong, Pané, Salvador, Nelson, Bradley J., and Choi, Hongsoo

Subjects
MICROMOTORS, ENVIRONMENTAL remediation, POLLUTANTS, IRON, HYDROGEN as fuel, LIFE spans
Abstract

Highlights: This review discusses the potential of degradable metallic micromotors for a variety of biomedical and environmental applications. The design principles, fabrication techniques and degradation mechanisms of degradable metallic micromotors are reviewed in detail. Challenges and future directions for the development of degradable metallic micromotors for real-life applications are presented. Synthetic micromotor has gained substantial attention in biomedicine and environmental remediation. Metal-based degradable micromotor composed of magnesium (Mg), zinc (Zn), and iron (Fe) have promise due to their nontoxic fuel-free propulsion, favorable biocompatibility, and safe excretion of degradation products Recent advances in degradable metallic micromotor have shown their fast movement in complex biological media, efficient cargo delivery and favorable biocompatibility. A noteworthy number of degradable metal-based micromotors employ bubble propulsion, utilizing water as fuel to generate hydrogen bubbles. This novel feature has projected degradable metallic micromotors for active in vivo drug delivery applications. In addition, understanding the degradation mechanism of these micromotors is also a key parameter for their design and performance. Its propulsion efficiency and life span govern the overall performance of a degradable metallic micromotor. Here we review the design and recent advancements of metallic degradable micromotors. Furthermore, we describe the controlled degradation, efficient in vivo drug delivery, and built-in acid neutralization capabilities of degradable micromotors with versatile biomedical applications. Moreover, we discuss micromotors' efficacy in detecting and destroying environmental pollutants. Finally, we address the limitations and future research directions of degradable metallic micromotors. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

41. An Electromagnetically Controllable Microrobotic Interventional System for Targeted, Real‐Time Cardiovascular Intervention (Adv. Healthcare Mater. 11/2022)

Author

Hwang, Junsun, primary, Jeon, Sungwoong, additional, Kim, Beomjoo, additional, Kim, Jin‐young, additional, Jin, Chaewon, additional, Yeon, Ara, additional, Yi, Byung‐Ju, additional, Yoon, Chang‐Hwan, additional, Park, Hun‐Jun, additional, Pané, Salvador, additional, Nelson, Bradley J., additional, and Choi, Hongsoo, additional

Published
2022
Full Text
View/download PDF

44. Strain sensitive flexible magnetoelectric ceramic nanocomposites

Author

Kim, Min-Soo, Kim, Donghoon, Aktas, Buse, Choi, Hongsoo, Puigmarti-Luis, Josep, Nelson, Bradley, Chen, Xiang-Zhong, and Pané, Salvador

Subjects
Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, Physical sciences [Applied Physics (physics.app-ph), FOS], Applied Physics (physics.app-ph)
Abstract

Advanced flexible electronics and soft robotics require the development and implementation of flexible functional materials. Magnetoelectric (ME) oxide materials can convert magnetic input into electric output and vice versa, making them excellent candidates for advanced sensing, actuating, data storage, and communication. However, their application has been limited to rigid devices due to their brittle nature. Here, we report flexible ME oxide composite (BaTiO3/CoFe2O4) thin film nanostructures that can be transferred onto a stretchable substrate such as polydimethylsiloxane (PDMS). In contrast to rigid bulk counterparts, these ceramic nanostructures display a flexible behavior and exhibit reversibly tunable ME coupling via mechanical stretching. We believe our study can open up new avenues for integrating ceramic ME composites into flexible electronics and soft robotic devices., arXiv

Published
2022
Full Text
View/download PDF

48. Multi-target cell therapy using a magnetoelectric microscale biorobot for targeted delivery and selective differentiation of SH-SY5Y cells via magnetically driven cell stamping

Author

Song, Hyunseok, primary, Kim, Dong-in, additional, Abbasi, Sarmad Ahmad, additional, Latifi Gharamaleki, Nader, additional, Kim, Eunhee, additional, Jin, Chaewon, additional, Kim, Samhwan, additional, Hwang, Junsun, additional, Kim, Jin-Young, additional, Chen, Xiang-Zhong, additional, Nelson, Bradley J., additional, Pané, Salvador, additional, and Choi, Hongsoo, additional

Published
2022
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results