UC Berkeley

Swimming microrobots have significant potential for biomedical applications and distributedsensing. To date, most work has relied on external fields for control control. To achieve autonomy, locally controllable propulsion mechanisms must be developed. This thesis presents an rotary inchworm motor designed to drive an artificial flagellum, inspired by bacterial flagellar motors found in nature. The design adapts electrostatic gap closing actuators with angled arms for rotational motion. The devices are fabricated in an SOI process with a bonded lid featuring through-wafer vias as a mechanical feedthrough for the flagellum. A hydrophobic coating is applied to prevent water ingress through small gaps, thus keeping the gap closing actuators dry. This process also provides an additional layer of routing for reduced complexity. Motors with rotation rates up to 633 rpm at actuation frequencies of 1.7 kHz are demonstrated to operate reliably in dry conditions. Additionally, promising electrical and optical results are presented, preventing water ingress to gap-closing actuators at low pressures. Effective operation of the mechanism underwater remains a challenge.