Effects of Geometric and Material Properties on Electrical Power Harvested From a Bimorph Piezoelectric Cantilever Beam

In this paper, a three-dimensional finite element (FE) model is developed to design a vibrating bimorph piezoelectric cantilever beam for energy harvesting. A parametric study of electric power generated as a function of the dielectric constant, transverse piezoelectric strain constant, length and thickness of the piezoelectric material, is conducted for a time-harmonic surface pressure load. The reference piezoelectric material used in the design is Lead Zirconate Titanate (PZT-5H). Complete transversely isotropic elastic and piezoelectric properties are assigned to the bimorph layers with brass chosen as the substrate material in the three-dimensional finite element model. The numerical analysis shows that a uniform decrease in thickness and length coverage of the piezoelectric layers results in a nonlinear reduction in power amplitude, which suggests optimal values. Using design of experiments (DOE), a study was conducted to determine the sensitivity of power with respect to the geometric and material variables.