US Patent 7530675 Piezoelectric actuator device

The present application is directed to piezoelectric actuator devices. One embodiment of a piezoelectric actuator comprises a chamber diaphragm having a major surface. A piezoelectric transducer is positioned on the major surface of the chamber diaphragm. The piezoelectric transducer has a major surface having a first dimension which is smaller than a corresponding second dimension of the major surface of the chamber diaphragm, so that the piezoelectric transducer underlaps the chamber diaphragm. The underlap ratio of the first dimension to the second dimension ranges from about 0.70 to about 0.99.