Micromechanical devices based on piezoelectric resonators

A piezoelectrically transduced resonator device includes a wafer having a substrate, a buried oxide layer formed on the substrate, and a device layer formed on the buried oxide layer, and a resonator suspended within an air gap of the wafer above the substrate, the resonator including a portion of the device layer, a piezoelectric layer, and top and bottom electrodes contacting top and bottom sides of the piezoelectric layer, wherein the portion of the device layer is not directly connected to the wafer and wherein the resonator is configured to move relative to the substrate under electrostatic force to tune the frequency of the resonator device when a direct current voltage is applied between the substrate and the portion of the device layer of the resonator