Nano porous piezoelectric energy harvester by surface effect model

Encouraged by the highly development of nano piezoelectric structures and the demand of new energy, this work proposes an nano energy harvester with porous piezoelectric materials. Based on Biot's porous elasticity, the analytical expressions of the nano porous piezoelectric energy harvester in thickness-shear mode are derived and calculated. The numerical results shows that the porous energy harvester behaves much better than its alternative with nonporous materials. The solid-fluid coupling piezoelectric constant affects the resonant frequency significantly, but the power peak slightly. However, the solid-fluid coupling dielectric constant can influence both the frequency and the power peak. Moreover, the surface effects on the energy harvester are discussed. The energy harvesting capacity can be advanced by increasing the residual surface stress, surface piezoelectric constant and surface solid-fluid coupling dielectric constant. The resonant frequency can be controlled and the energy capturing ability can be improved through adjusting the materials parameters.