Experimental comparison between a fractal-inspired multi-frequency piezoelectric energy converter and a traditional converter

Harvesting energy from ambient vibrations in order to power autonomous sensors is a challenging issue. The aim of this work is to compare the power output from an innovative multi-frequency fractal-inspired piezoelectric converter to that from a traditional multi-cantilever piezoelectric converter. The converters are designed in order to give the same eigenfrequencies in a given range and a prototype of both is built using commercial materials. The experimental tests investigate both the effect of the acceleration and of the resistive load applied to the converters for each of the three eigenfrequencies in the range between 0 and 120 Hz. The fractal-inspired converter exhibits a significantly higher specific output power at the first and third of the eigenfrequencies investigated. Copyright © 2013 by Alstom Technologie AG.