Surface Acoustic Wave Sensors

Abstract

Acoustic wave sensors are highly sensitive in detecting the properties of solid or fluid materials in contact with their surfaces, including the surface mass change, liquid density, liquid viscosity and electrical conductivity. In this paper, primarily, the commonly used acoustic wave sensors are reviewed and their mass sensitivities are compared. The fundamentals of the sensing system using the shear horizontal surface acoustic wave (SH-SAW) sensor on a 36° rotated Y-cut X-propagating LiTaO₃ are described. Since the high sensitivity of the electrical perturbation is a significant advantage of the SH-SAW sensor, its applications based on acoustoelectric interaction are also presented.