A scrape-through piezoelectric MEMS energy harvester with frequency broadband and up-conversion behaviors

Abstract

We propose a MEMS piezoelectric energy harvester with a wide operating frequency range by incorporating a high-frequency piezoelectric cantilever and a metal base as the top and bottom stoppers with a lowfrequency piezoelectric cantilever. Frequency up-conversion of the piezoelectric energy harvester is realized when the low-frequency piezoelectric cantilever impacts and scrapes through the high-frequency piezoelectric cantilever. For an input acceleration of 0.6 g, with top and bottom stopper distances of 0.75 and 1.1 mm, respectively, the operating frequency ranges from 33 to 43 Hz. The output voltage and power up to 95 mV and 94 nW can be achieved. Experimental results indicate that the frequency up-conversion mechanism significantly improves the effective power. © Springer-Verlag 2011.