| In this dissertation, the development of a first generation MEMS-based piezoelectric energy harvester is presented that is designed to convert ambient vibrations into storable electrical energy. The objective of this work was to model, design, fabricate and test MEMS-based piezoelectric cantilever array structures to harvest power from source vibrations.;The proposed device consists of a piezoelectric composite cantilever beam (Si/SiO2/Ti/Pt/PZT/Pt) with a proof mass at one end. The proof mass essentially translates the input base acceleration to an effective deflection at the tip relative to the clamp, thereby generating a voltage in the piezoelectric layer (using d 31 mode) due to the induced strain. An analytical electromechanical lumped element model (LEM) was formulated to accurately predict the behavior of the piezoelectric composite beam until the first resonance.;First, macro-scale PZT composite beams were built and tested to validate the LEM. In addition, a detailed non-dimensional analysis was carried out to observe the overall device performance with respect to various dimensions and properties. Various first generation test structures were designed using a parametric search strategy subject to fixed vibration inputs and constraints.;The proposed test structures thus designed using the electromechanical LEM were fabricated using standard sol gel PZT and conventional surface and bulk micro processing techniques. The devices have been characterized with various frequency response measurements and the lumped element parameters were extracted from experiments. Finally, they were tested for energy harvesting by measuring the output voltage and power at resonance for varying resistive loads. |
