Tunable topological edge states and energy harvesting of piezoelectric-inductance phononic crystals based on Su-Schrieffer-Heeger model

Based on Su-Schrieffer-Heeger (SSH) model, a one-dimensional tunable topological phononic crystal (PnC) was designed. Piezoelectric column with an inductance was designed as a scatterer embedded in the epoxy resin matrix. And the introduce of an inductance into each piezoelectric column resulted in a new Dirac point in band structure. Subsequently, the new Dirac point was operated to open/close by altering the intracell distance, and the trivial and non-trivial phase transition occurred simultaneously, which demonstrated the topological properties of PnC. The results showed that the obvious edge state was observed at the frequencies of 16.334-27.226 kHz by varying the inductance from 2.5mH to 9.5mH. And the immune of the edge state to the local defects was also verified. Furthermore, the energy harvesting of the wave propagation was performed, and the energy harvesting efficiency of the edge state case was about 40 times larger than that of bulk state case.