Multiple topological interface modes in electromechanically resonant piezoelectric beams

Topological insulators (TIs) have been rapidly developed for their defect-immune capability of wave transport, and promoted the innovation in designing smart devices with robust wave manipulation functions. In this paper, a tunable topological piezoelectric beam is designed by an elastic beam attached piezoelectric patches with shunting inductance circuits. Controllable topological phase transition is realized by adjusting the shunting inductances to alter the electromechanical resonances. Multiple topologically protected interface modes (TPIMs) are obtained by connecting two kinds of piezoelectric beams with different topological properties together. Furthermore, the effects of inductance deviations and structural defects on the topological beam are investigated to verify the robustness of the TPIMs. Finally, a novel topologically protected demultiplexer is designed to achieve the smart spatial separation of flexural waves based on the TPIMs. This demultiplexer broadens the applications of TIs and provides a new avenue for the separation and purification of elastic waves.

Automated summary

In this paper, a tunable topological piezoelectric beam is designed by adjusting shunting inductances. Multiple topologically protected interface modes (TPIMs) are obtained and the robustness of TPIMs is verified. A novel topologically protected demultiplexer is also designed for the spatial separation of flexural waves.