Three-dimensional piezoelectric PZT-air artificial materials, designed using the Optimal Design by the Homogenization Method, with predicted hydrostatic piezoelectric coefficient of 427 pC/N and a hydrophone figure of merit of 29 pm(2)/N were realized and measured. The measured hydrostatic piezoelectric coefficient was 329 pC/N and a hydrophone figure of merit was 19 pm(2)/N. The differences between predicted and observed properties were ascribed to insufficient polarization, due to the field distribution during poling.