Abstract: A multi-layer piezoelectric transformer device includes first and second electroactive members having electrodes bonded to each of their opposing major faces; and a bonding layer disposed therebetween. The first and second electroactive members are polarized in a thickness direction, between their two major faces, such that when energized by an electric field the first and second electroactive members longitudinally strain. The first and second electroactive members are arranged such that deformation of one electroactive member results in corresponding deformation of the other electroactive member. The device provides substantial transformation ratios in which relatively high power may be transferred in relation to the size of the unit, operability over wide input and output frequency bandwidths, and electrical isolation of the voltage and current at the input to the device from the voltage and current at the output of the device.

Abstract: A piezoelectric snap-actuator includes a piezoelectric bender element with electrodes disposed on each major face, a spring member for causing the device to snap from a first neutral position to a second neutral position, a prestress layer for applying a compressive force to the piezoelectric bender element, and adhesive layers is provided. The piezoelectric bender element and the spring member are each bonded to the opposite faces of the prestress layer by an adhesive layer. The device assumes one of two neutral positions when not electrically energized. Due to the direction of poling of the piezoelectric bender element, when the piezoelectric bender element is electrically energized it strains in a longitudinal direction. This strain causes the device to deform. When the electrical energy is turned off, the device returns to one of the two neutral positions.

Abstract: A piezoelectrically actuated fluid pump including a pump housing, a pump chamber, inlet and outlet ports for communicating the pump chamber with the exterior of the pump housing, valves for opening and closing the ports, two prestressed piezoelectric diaphragm members which are self-actuated, and a power source is provided. The diaphragm members include a prestressed piezoelectric element which is durable, inexpensive and lightweight as compared with prior diaphragm pumps of comparable discharge capacity, and is actuated via electrical signals from an outside power source. No exterior mechanical parts for driving the diaphragm members are necessary. A modification is disclosed in which a central computer independently controls the phase angle of oscillation of the two diaphragm members, providing precise flow rate control.