Switching band-gaps of a phononic crystal slab by surface instability

High-amplitude wrinkle formation is employed to propose a one-dimensional phononic crystal slab consists of a thin film bonded to a thick compliant substrate. Buckling induced surface instability generates a wrinkly structure triggered by a compressive strain. It is demonstrated that a surface periodic pattern and corresponding stress can control elastic wave propagation in the low thickness composite slab. Simulation results show that the periodic wrinkly structure can be used as a transformative phononic crystal that can switch the band diagram of the structure in a reversible manner. The results of this study provide opportunities for the smart design of tunable switches and frequency filters at ultrasonic and hypersonic frequency ranges. (paper)