PURPOSE: To make a porous piezoelectric material element having high percentage of void and high pore diameter develop its sufficient performance and reduce generation of accident due to disconnection by installing metal foils of the particular thickness as the electrodes to a porous ceramic material having piezoelectric characteristic.
CONSTITUTION: A metal foil in the thickness of 0.5mm or less is installed as an electrode to a porous ceramic material having piezoelectric characteristics with porosity of 50 to 85% and pore diameter of 0.01mm or more. For example, polystyrene sphere classified into the diameter of 3.5mm and spray particles of lead titanate zirconate are dry mixed in the volume ratio of 7:3, and are then press-molded with the molding dies of 50×50×10mm to obtain a porous piezoelectric precursor. Thereafter, it is baked within an electric furnace for two hours at 1200°C to obtain spherical porous piezoelectric material with the void of 61% and pore diameter of 3.1mm. Then, a copper foil in the thickness of 0.01 to 0.1mm is attached thereto with a bonding agent having electric conductivity and it is then polarized at 2kV/mm for an hour within fluorocarbon solution of 120°C to produce porous piezoelectric element.
OMURA SEIJI