A long-stroke MEMS actuator based on cascaded stages of innovative pass-through comb fingers

A long-stroke Micro-Electro-Mechanical System (MEMS) actuator, based on an innovative pass-through comb finger mechanism using cascaded stages, is presented, fabricated with a dual-layer process, and experimentally tested. Thanks to the novel electrostatic actuation system here proposed, the actuator is able to generate a displacement of 30 μ m , for a proof-mass footprint of 1 × 1.1 mm 2 at only < 60 V actuation. Experimental tests well-agree with predictions obtained a-priori with the numerical model. The work thus proves the design strategy of such a remarkable comb-finger mechanism, and opens the path to a new class of long-stroke, electrostatically driven, MEMS actuators. • An innovative electrostatic actuation scheme is proposed: it consists in pass-through comb fingers. • Pass-through comb fingers are actuation electrodes with no theoretical displacement limit. • A readout scheme for open-loop characterization and to conceive closed-loop control is included. • A numerical model is detailed to justify design choices and to guide the system-level model. • With a footprint of 1 × 1.1 mm 2 and a voltage lower than 60 V, it achieves a displacement of 30 μ m .