Analysis of piezoelectric circular diaphragm energy harvesters for use in a pressure fluctuating system

This paper presents an analysis of the energy generating performance in a pressure-loaded system using piezoelectric transducer technology. The energy harvesting device in this study is a partially covered, simply supported piezoelectric unimorph circular plate to convert energy from fluctuating pressure into electrical energy. The analysis includes comprehensive modeling and a parametric study to provide a design primer for a specific application in which the frequency of fluctuating pressure is well below the natural frequency of the harvester. An expression for the total power output from the device for a given applied pressure is shown, and then used to determine optimal design parameters. It is shown that the device's deflection and stress under load are the limiting factors in the design. The analytical results indicate that the PMN-PT harvesters can generate over one order of magnitude more power than the PZT harvesters for any substrate material. Some possible factors that can degrade energy harvesting performance are also discussed.