A closed-form approach for frequency tunable comb resonators with curved finger contour

Frequency tunable comb resonators have been successfully designed and demonstrated based on a closed-form approach of a curved comb finger contour. Experimentally, the resonant frequency of a laterally driven comb resonator with 186 pairs of curved finger contour has been reduced by 55% from the initial frequency of 19 kHz under a bias voltage of 150 V. The corresponding effective stiffness has been decreased by 80% from the initial value of 2.64 N/m. This closed-form design approach could be extended to microsystems based on electrostatic comb-shape structures such as microaccelerometers, microgyroscopes, and micromechanical filters.