Modeling and Analysis the Effect of PZT Area on Square Shaped Substrate for Power Enhancement in MEMS Piezoelectric Energy Harvester

Modeling and analysis of a MEMS piezoelectric (PZT-Lead Zirconate Titanate) unimorph cantilever with different substrates are presented in this paper. Stainless steel and Silicon < 110 > are considered as substrate. The design is intended for energy harvesting from ambient vibrations. The cantilever model is based on Euler-Bernoulli beam theory. The generated voltage and power, the current density, resonance frequencies and tip displacement for different geometry (single layer and array structure) have been analyzed using finite element method. Variation of output power and resonant frequency for array structure with array elements connected in parallel have been studied. Strain distribution is studied for external vibrations with different frequencies. The geometry of the piezoelectric layer as well as the substrate has been optimized for maximum power output. The variation of generated power output with frequency and load has also been presented. Finally, several models are introduced and compared with traditional array MEMS energy harvester.