Experimental and averaged finite element modelling data for barium titanate with a porous sandwich layer surrounded by dense outerlayers. The experimental data includes measurements of piezoelectric strain coefficients, permittivity and energy harvesting figure of merit for sandwich layer porosity of 50 and 60 vol.% and varying porous layer thickness.

The data from the finite element modelling includes calculated effective piezoelectric and dielectric properties for barium titanate with sandwich layer porosity of 0 to 60 vol.% and porous layer relative thickness of zero (i.e. no porous layer) to one (i.e. no dense outerlayers), as well as detailing the fraction of material poled due to the distribution of porosity throughout the complex structure.