A large displacement, high frequency, underwater microelectromechanical systems actuator

Abstract

Here, we demonstrate an in situ electrostatic actuator that can operate underwater across a wide range of displacements and frequencies, achieving a displacement of approximately 10 μm at 500 Hz and 1 μm at 5 kHz; this performance surpasses that of existing underwater physical actuators. To attain these large displacements at such high speeds, we optimized critical design parameters using a computationally efficient description of the physics of low quality (Q) factor underwater electrostatic actuators. Our theoretical model accurately predicts actuator motion profiles as well as limits of bandwidth and displacement.