Design of Acoustic Energy Harvesting Unit Using Piezo-Electric Diaphragm

Abstract

Nowadays, much effort is directed towards solving the energy crisis resulting from depletion of fossil fuel. This has resulted in new approaches in energy industry like developing new sources of energy and harvesting already wasted energy. One of the commonly wasted forms of energy is the vibrational energy existing in noise produced from daily life activities. The goal of this work is to put a design for an Acoustic Energy Harvesting unit that is based on a Piezo-Electric transducer that can convert sound energy of noise into electric energy. The design process followed an experimental approach. It included open circuit as well as closed circuit experiments. The open circuit experiment aimed at finding a good initial guess for incident sound frequency for optimum energy harvesting while the closed circuit experiment aimed at finding the suitable circuit electrical impedance that would maximise energy harvesting at the frequency obtained from the initial guess. The proposed design can harvest power of 0.043 μW, with voltage of 21 mV and current of 2.05 μA, at power harvesting density of 2.8x . These results are achieved at incident sound of sound pressure level (SPL) of 118 dB and frequency of 466.2 Hz.