Flexural wave energy harvesting by the topological interface state of a phononic crystal beam

In this study, we design the 3D-printed phononic crystal (PnC) beam with the topological interface state for harvesting the mechanical energy of flexural waves. The PnC beam is formed by arranging periodic grooves on its surface. The PnC beam with either topologically trivial or non-trivial phase can be achieved via changing the distance between the grooves. The topological interface state is then generated by combining two PnCs with distinct topological phases. The existence of the interface state of the PnC beam is verified both numerically and experimentally. To convert the mechanical energy into the electricity, a piezoelectric disc is attached at the interface of the proposed PnC beam. Compared to the reference beam harvester, the measured output power is significantly amplified by the PnC harvester at the frequency corresponding to the interface state. Furthermore, the PnC beam energy harvester based on the topological state exhibits robustness against geometrical disorders. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

In this study, a 3D-printed phononic crystal (PnC) beam with a topological interface state is designed for harvesting the mechanical energy of flexural waves. By changing the distance between grooves, PnC beams with different topological phases can be achieved and the existence of the topological interface state is verified both numerically and experimentally. By attaching a piezoelectric disc at the interface, the mechanical energy can be converted into electricity. The PnC harvester shows significantly amplified output power at the frequency corresponding to the interface state compared to traditional beam harvesters.