Viscous losses of shear waves in layered structures used for biosensing

Love-waves have proved to be best-suited for liquid sensing applications. For (bio)chemical sensing applications, we utilize a microacoustic delay line featuring a multilayered waveguide supporting a generalized Love-wave mode. The top layer is a chemical interface, which selectively adsorbs certain target molecules in the adjacent liquid. The interface materials show viscoelastic losses leading to an unwanted damping of the wave. We analyzed the resulting losses and present illustrative results that provide design rules for the interface thickness.