Electrical capacitance with meshed electrodes for piezo- and pyro-electric energy harvesting applications

When utilizing a meshed electrode design for piezo-and pyro-electric harvesting, there are changes in the electrical capacitance with mesh density and surface electrode coverage. For square meshed electrodes, geometrical limits are identified and the applicability of the parallel plate assumption is verified. The reduction of electrode coverage and element capacitance is examined with respect to the aspect ratio feature size relative to the dielectric thickness. Finite element analysis reveals the presence of electric fields that are four times stronger with the meshed electrode design compared to fully covered electrodes. The electrical energy stored in the harvester with meshed electrodes, and its availability for discharge, is only 4 % smaller than with a fully covered design.