Modeling of piezoelectric energy harvester: influence of electrode/piezoelectric width ratio on induced voltage

Research in piezoelectric energy harvester (PEH) for powering micro-scale devices have been gaining momentum in the past decade. The modeling works are critical to accurately predict performances of PEH structures with different dimensions and active materials before committing to expensive fabrication processes. In this paper, a static modeling of unimorph cantilever PEH in transverse mode is performed. Equations for induced voltage are derived, taking onto consideration different width between electrode and piezoelectric layers (referred to as width ratio). To illustrate the results of this model, we plot the induced voltage versus input force and width ratio of PEH using five variants of Lead Zirconate Titanate (PZT) materials with parameters from commercial datasheets. Finally, the limitation of this model and possible use to improve the performances of PEH are elucidated.