Support Losses in Micromechanical Resonators Under Electrostatic and Piezoelectric Actuations

Elimination of support losses has been important in boosting quality factors of micromechanical resonators. A high-quality factor is one of the requirements for the realization of micromechanical resonators applied to modern communication systems, sensors, etc. In this paper, we present theoretical and experimental studies on the support losses in micromechanical resonators driven by electrostatic and piezoelectric actuations separately. We experimentally demonstrate that a piezoelectric actuation can take less support loss than its electrostatic counterpart using an AFM probe actuated by piezoelectric and electrostatic effects, respectively. The study also shows that the energy loss to the support in the piezoelectric resonators could be reduced by decreasing the clamped region area of the piezoelectric material layer on the substrate, and using the piezoelectric material with a smaller ratio of the piezoelectric coefficients along the thickness to the length.