Dr. U Kei Cheang is presently an associate professor in the Department of Mechanical and Energy Engineering at Southern University of Science and Technology (SUSTech). In 2015, he completed his Ph.D. degree in Mechanical Engineering at Drexel University, where he held the NSF GRFP, NSF IGERT, and NSF EAPSI Fellowships. Dr. Cheang joined SUSTech in 2017 and has been leading a team as an independent PI to develop micro- and nanorobots. His work on robotic microswimmers received the UNESCO Netexplo Top 10 Award in 2016. Dr. Cheang was awarded the MOST High-End Foreign Expert Award in 2019 and the Shenzhen Excellent Young Scholars Award in 2022.

Topic title: Fabrication, Control, and Biomedical Applications of Magnetically Actuated Achiral Microswimmers

Abstract:

Interest in microrobotics has grown rapidly over the past decade. Recent developments in the field demonstrated the potential to use artificial robotic microswimmers to significantly improve various types of biomedical applications by enabling precision control at scales that are inaccessible using traditional surgery tools. For robotic microswimmers to be used in practical applications, they must be mass-manufactured at low cost using conventional technologies, functionalized for biomedical applications, remotely actuated using a magnetic field, and controllable in complex environments. To this end, researchers studied many different types of microrobots/swimmers to meet these criteria. Here, we introduce the magnetically-actuated achiral microswimmers, which require neither chirality nor flexibility to generate propulsion. Achiral microswimmers can be mass-manufactured using conventional photolithography, which is essential for practical applications. When controlled via a rotating magnetic field, the microswimmers can swim in bulk fluid, roll on surfaces, and navigate through microchannels with complex and narrow pathways, demonstrating their potential for targeted therapy. Characterization of their motion showed that non-Newtonian fluids did not hinder their swimming, indicating that achiral microswimmers can potentially adapt to different biofluids. The microswimmers were experimentally verified to be biocompatible and functionalized for various applications, including drug delivery, stem cell delivery, and biosensing. In this talk, we will present recent research on the fabrication, functionalization, actuation, and control of achiral microswimmers and discuss their potential as platforms for biomedical applications.