An electrothermal/electrostatic dual driven MEMS scanner with large in-plane and out-of-plane displacement

This paper reports the design, fabrication and characterization of an MEMS scanner with combined electrothermal and electrostatic actuation. The scanner can generate large out-of-plane and in-plane displacement. The out-of-plane displacement is achieved by a pair of electro-thermal bimorph actuators, which is as much as 370 µm at only 2.5 V. The in-plane displacement is obtained by employing electrostatic comb drives, which can achieve fast scan up to 10 kHz. A special process has been developed to fabricate microstructures with both thin-film bimorphs and single-crystal-silicon comb drives.