A Pspice model to numerically design piezoelectric-based acoustic power transfer

Acoustic power transfer (APT) has become a strategic stake with the increase of wireless smart devices located in electromagnetic proof environments. This is especially the case for medical implants where the transferred power has to go through human tissues, itself made of different layers (epidermis, dermis, muscle, bones), and through the metallic case of the medical implant. Each of these layers are mechanically coupled, making the optimization of the emitter and receiver of such system a complex task. To overcome this issue, we developed a procedure based on Pspice to accurately simulate APT between an emitter and a receiver, as it propagates through an intermediate layer. The procedure is based on Leach model which is the Pspice equivalent model of Mason electro-mechanical analogy. In this article, we propose a model which fits two 3-layer APT experiments, consisting in piezoelectric emitters and receivers with an intermediate layer of alternatively titanium and tungsten. The results provided by the simulations give a qualitative fitting of the APT and would enable to design, study and optimize n-layer APT systems for applications such as wireless medical implant recharging.