Thickness shear-mode acoustic wave sensor in liquid and the frequency interference between laterally coupled channels

Abstract

In this research work, a new mechanical slip interfacial model between liquid and surface of acoustic wave sensor is proposed, which considers the properties of the contact interface, such as the interactive strength, contact molecular size and the viscosity of the liquid in the theoretical analysis. Correlation of the proposed model with exiting models is discussed. Based on the slip modeling, a new usage of TSM to detecting the interface properties between solid and liquid is presented. Employing the Mindlina??s 1-D and 2-D equations foe piezoelectric materials, the effect of partially mass absorbed on the TSM sensor surface and the energy trapping effect of the bi-step mesa TSM resonator are analyzed theoretically. The frequency interference between the lateral coupled channels is analyzed by using the 3-D finite element method. The coupling strength between channels is highly related to the interval and the thickness of electrodes.