Mass sensitivity of thickness-twist modes in a rectangular piezoelectric plate of hexagonal crystals

Mass sensitivity of thickness-twist vibration modes in a rectangular plate piezoelectric resonator of 6-mm crystals are obtained from the three-dimensional equations of linear piezoelectricity. The boundary conditions at the finite-plate boundaries all have been taken into consideration. The solutions obtained are exact, which is relatively few for piezoelectric problems over finite domains. The results are fundamental and useful to the understanding and design of piezoelectric resonators and acoustic wave sensors made of polarized ceramics, ZnO and AlN