Electrothermal SCS Micromirror with Large-Vertical-Displacement Actuation

This paper reports a novel large-vertical-displacement (LVD) microactuator that can generate large piston motion at low driving voltage. A LVD micromirror device has been fabricated by using a unique DRIE CMOS-MEMS process that can simultaneously provide thin-film and single-crystal silicon microstructures. With only a 0.7 mm by 0.32 mm sized device, the LVD micromirror demonstrated a vertical displacement of 0.2 mm at an actuation voltage of 6 V d.c. This device can also perform bidirectional rotational scanning through the use of two bimorph actuators. The micromirror can rotate ± 20°, and has negligible initial tilt angle and high scanning speeds (~2 kHz).