The propagation of Lamb waves in an anisotropic plate bordered with liquid layers

Based on elastic wave propagation theory, a dispersion equation for thin anisotropic plate (such as commonly used ZnO) bordered with liquid layers is derived. Higher symmetry crystals, such as orthorhombic, tetragonal, cubic, isotropic, are contained implicitly in this analysis. For the case of one liquid layer loading, numerical calculations show that the phase velocity changes periodically with the thickness of liquid layer. When the thickness of the anisotropic plate 2d is very small, mass sensing application of A₀ mode Lamb wave is also discussed.