A high-sensitivity pressure sensor based on surface transverse wave

A new scheme for STW-based pressure sensors with high performance has been proposed. Different from the conventional analytical procedure using the perturbation theory, the pressure-induced frequency shifts for STW on quartz is obtained utilizing a Green's function simulator and the effective material constants dependent on pressure biasing have been calculated by the finite element method (FEM). The normalized pressure sensitivity (NPS) of STW on quartz as a function of the cut orientation in vicinity of BT-cut quartz has also been calculated, and the calculated results demonstrate that all the NPS on the given cut-orientation are 3 times higher than the commonly used ST-cut quartz of Rayleigh mode. To further improve the whole performance of the sensor, an optimized sensor configuration with an equi-intensity cantilever is proposed, whose geometry has been determined by using FEM software. The experimental results demonstrate that the pressure sensitivity of the proposed STW-based pressure sensors is sufficiently high and the relative frequency shift varies linearly with pressure loading.