Energy Harvesting From Vibration With Alternate Scavenging Circuitry and Tapered Cantilever Beam

Abstract

Piezoelectric transducers are increasingly being used to harvest energy from environmental vibrations in order to either power remote sensors or charge batteries that power the sensors. In this paper, a new voltage compensation scheme for high-voltage-based (> 100 V) energy harvesting is introduced, and its fundamental concepts, as well as the operation details, are elaborated. This scheme, when applied to the voltage inversion method [synchronized switch harvesting on inductor (SSHI)], provides an increase of over 14% in harvested power when compared to the parallel inversion method (parallel SSHI) alone and more than 50% in the case of series inversion method (series SSHI). Second, tapered cantilever beams were shown to be more effective in generating a uniform strain profile over rectangular and trapezoidal beams if they are precisely shaped, resulting in a significant increase in harvested power over available methods in the literature from laboratory experimental tests. In addition, a simplified method to design such a beam is introduced. Finally, a field test of the proposed tapered beam is conducted by using a dozer for earth-moving applications, and experimental results are discussed.