Bidirectional Electrostatic Rotary MEMS Actuator Achieving ±3.2° Angular Displacement

In this work, we present a rotary micro-electro-mechanical system (MEMS) structure utilizing an electrostatic actuation mechanism. The design comprises a set of circular-shaped springs and curved comb fingers to provide bidirectional rotation while minimizing lateral displacement. This structure was fabricated using the PiezoMumps commercial microfabrication process. An analytical model is employed to predict the behavior of the design, and is validated through finite element method (FEM) simulations and prototype measurements. The results indicate that the structure can provide both clockwise and counterclockwise displacements up to 3.2° at an actuation voltage of 170 V. A good agreement is observed between analytical, numerical, and experimental results. This structure holds great potential for applications requiring configurable features, such as photonic systems, due to its precise displacement control and low power consumption.