Acoustic energy transfer using piezoelectric transducers

Acoustic energy transfer (AET) is considered to be a promising technology without electromagnetic interference and safety issue compared to other wireless power transfer methods, especially for biomedical applications. In this paper, an AET system using piezoelectric transducers is modelled by equivalent circuit representation and finite element method, which in general give consistent results. A parametric study is then conducted to understand the influence of the sizes of barrier and piezoelectric transducers as well as the load resistance on the performance of the AET system. It is found that the area of the barrier has negligible impact on the performance, but the thickness of the barrier does, and the thinner barrier is favorable. In addition, it is found that a transfer efficiency of over 90% can be achieved if the transducers are optimized with thickness of 1.8-2.0 mm and the diameter of 24 to 26 mm. As the load resistance increases from 5 Ω to 400 Ω, the maximum efficiency of about 90% is achieved with a medium load resistance. These findings provide useful guidelines for AET system design.