Low voltage electrostatic actuation and angular displacement measurement of micromirror coupled with resonant drive circuit

A micromirror driven by electrostatic actuation methods requires high actuation voltage supplied by a high voltage amplifier and suffers from the pull-in phenomenon that limits an operation range of a micromirror to 44 % of its maximum angular displacement. To provide practical solutions to this high actuation voltage and a limited operation range, we present complete analytical and numerical models of a micromirror coupled with resonant drive circuits that enable us to actuate a micromirror at much lower supply voltage than that of conventional voltage control circuits. The presented work also facilitates the stability analysis of a micromirror coupled with a resonant drive circuit and provides how a parasitic capacitance of a micromirror and a quality factor of a resonant drive circuit affect an operation range of a micromirror. Furthermore, we present a new method of an angular displacement measurement of a micromirror by sensing the phase delay of an actuation voltage with reference to an input voltage.