二维声学黑洞在压电振动能量收集中的应用

Acoustic black hole (ABH) effect can generate strong energy concentration. And it can convert low quality vibration energy of high frequency and low amplitude into high-quality vibration energy with high amplitude for its being easy to utilize. Here, an annular 2-D ABH piezoelectric energy collection device was proposed and studied. Finite element analysis results showed that the annular 2-D ABH structure can significantly improve energy collection efficiency within a wide frequency domain. An experimental testing platform for the annular 2-D ABH piezoelectric energy collector was built and the correctness of simulation results was verified with experiments. It was shown that compared with classical 2-D ABH structures, the annular 2-D ABH structure has better energy collection efficiency and structural strength. Then, effects of factors of geometric size, etc. of piezoelectric sheets on the device' s energy collection efficiency were analyzed to obtain geometric size range which can achieve higher output power. Finally, the orthogonal test design was performed to study comprehensive effects of multiple factors, such as, cutoff thickness, piezoelectric sheet size, central platform diameter and power exponent.