Effect of a viscous liquid layer on the transverse surface waves in transversely piezoelectric materials with unattached electrode

The propagation of the transverse surface waves in an unbounded piezoelectric half-space with a viscous liquid layer between the half-space surface and an unattached electrode is analyzed. An exact dispersion relation is obtained from the equations of the linear theory of piezoelectricity. Results show that the wave speed is sensitive to the viscous coefficient, the mass density and the dielectric permittivity of the fluid layer. Especially, the phase velocity changes linearly with the increasing mass density when other parameters keep constant, which can be used to manipulate the behavior of the waves and has implications in acoustic wave devices.