Modeling of an energy harvester with porous piezoelectric/piezomagnetic nanocomposite structure

Micro-energy harvesters are attracting more and more attention due to the demand of the miniaturization and the self-power for the electrical devices. A three-layered porous piezoelectric (PE)/piezomagnetic (PM) energy harvester at the nanoscale is modeled in this paper. The layered PE/PM structure works in the magnetic field; the electrical power can be obtained from the PE layer due to the magnetostriction of the PM layers. Based on the surface elasticity and Boit’s porous theory, the governing equations and the analytical expressions of the harvester with the thickness-shear mode are derived. The numerical analysis indicates that the electrical energy capture capability of the porous PE/PM energy harvester is much superior to its nonporous alternative. Then, the influences of the porous properties, the surface effects, and the constitution of the PE/PM materials on the energy capture performance are discussed. The results indicate that the nano PE/PM energy harvester with pores can be controlled and optimized by improving the porous, surface, and geometrical parameters.