Toward Swimming Medical Microrobots: Design and Characterization of a MEMS Motor for Electrostatic Actuation in Fluid

Summer 2017

Ryan Shih : Electrical Engineering and Computer Science

Mentor: Kristofer Pister, Michel Maharbiz

Microelectromechanical systems (MEMS) are sub-millimeter structures that combine electrical and mechanical principles to produce novel sensors, actuators, and transducers for complicated tasks at the microscale. While most MEMS research focuses on devices operating in air, biomedical applications and the parallel growth of microfluidics have stimulated efforts towards MEMS operation in fluid, especially biological media. One goal of such operation is to develop a microrobot capable of entering the human body and performing medical procedures such as diagnostics, drug delivery, local tissue repair, and surgery. Whether this microrobot is autonomous or externally controlled, its basic objectives are to sustain self-powered untethered operation, exhibit smooth propulsion, and perform the necessary tasks of a medical procedure. While power sources are unlikely to utilize moving parts, propulsion and medical procedures require mechanical movement which must in turn be supplied by an on-board motor. This motor must be low-power, fully functional when immersed in biological media, and constructed of biocompatible materials. I hope to design and characterize a MEMS motor for medical microrobots exhibiting these characteristics and demonstrate its successful operation in biological media.

I would like to extend my deepest gratitude to the Rose Hills Foundation for their generous support of my research endeavors. This opportunity gave me the chance to perform work in the fields I hope to dedicate my life too, and has provided me with valuable insights into the structure of research. Over the course of 10 or so weeks, I learned how to design MEMS (microelectromechanical systems) devices, and have performed extensive testing on their behavior in fluids. My findings indicate that we should be able to run MEMS motors in fluid, implying in turn that microrobots could run in fluid.