Large Angle Parametrically Excited Tilting Micro Actuator

We present novel operational principle of a tilting MEMS device based on parametric excitation and linear to angular motion transformation. The device is fabricated using a single layer of silicon on insulator (SOI) wafer and combines simple fabrication process with several beneficial features including large tilting angles, wide bandwidth, low sensitivity to deviation in geometrical and operational parameters and low actuation voltage. A theoretical feasibility and performance study was carried out using a lumped model of the device and verified by a coupled three-dimensional simulation. Parametric excitation of the tilting motion was demonstrated experimentally using and external piezoelectric transducer and tilting angles of 39° were registered. The suggested operational approach could be efficiently implemented in many MEMS based applications incorporating tilting elements including micromirrors, bio medical devices and inertial sensors.