Resonant-frequency tuning of angular vertical comb-driven microscanner

The resonant-frequency tuning of a self-aligned angular vertical comb-driven electrostatic microscanner is demonstrated by the electromechanical spring effect. The microscanner is fabricated on a silicon-on-insulator wafer using the plastic deformation of silicon. A tuning electrode is fabricated to be electrically separated from the actuation electrode to tune the resonant frequency by adjusting the applied direct-current voltage bias. The experimentally obtained maximum resonant-frequency shift was 3.2% when the resonant frequency of 3167 Hz is reduced to 3066 Hz when a tuning voltage of 30 V was applied while maintaining the actuation voltage. The method enables facile frequency tuning without any permanent geometrical modification to the microscanner.