Reconfigurable topological phononic crystal slabs

Highlights: • We propose two-dimensional reconfigurable phononic crystal slabs supporting topological edge states of Lamb waves. • The pseudospin–orbit coupling is achieved by simply shifting the sandwich cylinders. • The robustness of topological edge states against various kinds of defects is demonstrated. • The reconfigurable design provides a platform for controlling of Lamb waves along arbitrary pathways. - Abstract: We propose two-dimensional reconfigurable phononic crystal slabs that support topologically protected edge states for Lamb waves. It consists of a triangular lattice of triangular-like air holes perforated in a slab and two sandwich cylinders are placed in the matrix of each unit cell. The pseudospin–orbit coupling is achieved by shifting the sandwich cylinders up or down. The robust transport of Lamb waves along reconfigurable interfaces is further demonstrated. The dynamically reconfigurable design provides an excellent platform for tuning the frequency range of topological edge states and steering efficient transport of Lamb waves along arbitrary pathways, which can be employed for elastic-wave communications, signal processing, and sensing.