Optimizing piezoelectric receivers for acoustic power transfer applications

• Published in: Smart materials and structures Vol. 27; no. 7; pp. 75024 - 75033
• Main Authors: Gorostiaga, M, Wapler, M C, Wallrabe, U
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.07.2018
• Subjects: acoustic power receiver; acoustic power transfer; efficiency; energy harvesting; optimization; piezoelectric transducer
• ISSN: 0964-1726; 1361-665X
• DOI: 10.1088/1361-665X/aabf09

In this paper, we aim to optimize piezoelectric plate receivers for acoustic power transfer applications by analyzing the influence of the losses and of the acoustic boundary conditions. We derive the analytic expressions of the efficiency of the receiver with the optimal electric loads attached, and analyze the maximum efficiency value and its frequency with different loss and acoustic boundary conditions. To validate the analytical expressions that we have derived, we perform experiments in water with composite transducers of different filling fractions, and see that a lower acoustic impedance mismatch can compensate the influence of large dielectric and acoustic losses to achieve a good performance. Finally, we briefly compare the advantages and drawbacks of composite transducers and pure PZT (lead zirconate titanate) plates as acoustic power receivers, and conclude that 1-3 composites can achieve similar efficiency values in low power applications due to their adjustable acoustic impedance.