Low Voltage Piezoelectric Composite for Transducer Applications

This invention generally relates to an acoustic transducers electromechanical substrate. More particularly, the invention relates to a piezoelectric polymer composite substrate enabling an array of transducers capable of being used with lower voltage than prior art transducers. A piezoelectric ceramic polymer composite is provided with piezoelectric ceramic pillars having intermediate electrodes. These intermediate electrodes reduce the voltage necessary to achieve a given polarizing electric field within the piezoelectric ceramic pillars. Upper and lower electrodes are provided on the surfaces of the composite substrate. These electrodes are electrically joined to the intermediate electrodes by insulated electrical traces. The piezoelectric ceramic phase geometry may include either 1-3 rods or 2-2 bars connectivity. The number of electrode pairs is limited only by the fabrication process. The lateral distribution of these piezoelectric pillars is decoupled using a polymer backfill material. Upper and lower electrodes can be partitioned to form an array of transducer elements.