Active Control Topological Valley Modes in Metamaterial Plates

Abstract

Phononic crystals and metamaterials have a unique band structure that allows for the existence of topologically protected surface states. The topologically protected edge states can guide elastic waves without significant scattering or loss of energy. One of the most promising applications of topological insulators in wave guiding is in the field of acoustics, where they can be used to design highly efficient and robust acoustic wave guides. However, the high efficiency, precision, reconfigurability, and robustness of elastic waves remains challenging. The topological insulators provide a feasible method to design high-efficiency, robust, and low-backscattering waveguides. In this work, a novel design of hexagonal metamaterial plates composed of a base plate and piezoelectric patches is proposed. The hexagonal metamaterial plate can generate robust topologically protected edge waves via active control. The paths of the topologically protected edge waves can be tuned by adjusting the control parameters. The robustness and efficiency of the proposed hexagonal metamaterial plate are testified to by the numerical examples. These findings provide systematic theoretical guidelines for designing reconfigurable wave guides, elastic wave splitters, and novel elastic wave devices and hold great promise for the development of high-performance and versatile wave guide technologies with potential applications in a wide range of fields.