A piezoelectric cooling system and method for driving the cooling system are described. The piezoelectric cooling system includes a first piezoelectric cooling element and a second piezoelectric cooling element. The first piezoelectric cooling element is configured to direct a fluid toward a surface of a heat-generating structure. The second piezoelectric cooling element is configured to direct the fluid to an outlet area after heat has been transferred to the fluid by the heat-generating structure.

A piezoelectric cooling system and method for driving the cooling system are described. The piezoelectric cooling system includes a first piezoelectric cooling element and a second piezoelectric cooling element. The first piezoelectric cooling element is configured to direct a fluid toward a surface of a heat-generating structure. The second piezoelectric cooling element is configured to direct the fluid to an outlet area after heat has been transferred to the fluid by the heat-generating structure.

A transducer includes a first piezoelectric layer; and a second piezoelectric layer that is above the first piezoelectric layer; wherein the second piezoelectric layer is a more compressive layer with an average stress that is less than or more compressive than an average stress of the first piezoelectric layer.

A transducer includes a first piezoelectric layer; and a second piezoelectric layer that is above the first piezoelectric layer; wherein the second piezoelectric layer is a more compressive layer with an average stress that is less than or more compressive than an average stress of the first piezoelectric layer.

A piezoelectric energy generator for a stadium, auditorium or other venue includes one or more tiles or mats, with each tile having one or more piezoelectric transducer devices formed therein such that voltage and current are generated when pressure is applied to the piezoelectric transducers, such as by people walking or stomping on the tiles. The tiles and piezoelectric devices are interconnected and connected to centrally located control and conditioning circuitry, which conditions the generated electricity for usage, storage, or transmission to an external power grid.

A field-driven electroactive polymer actuator is provided with a current sensor for sensing a current flowing to the actuator. A control circuit is used for driving the actuator which includes a voltage source. The driving of the actuator is controlled in dependence on the sensed current, thereby to provide a predetermined charge delivery for particular changes in actuation level of the actuator. This provides a combined voltage-based and current-based drive scheme for a voltage-driven EAP actuator, and it enables mechanical movements of the actuator to be more reliably repeated.

A piezoelectric device includes a substrate on which a plurality of recesses are arranged in a first direction, a vibration plate, and a piezoelectric actuator having a first electrode, a second electrode and a third electrode, a fourth electrode, and a piezoelectric layer, in which a plurality of active portions are provided, the second electrode and the third electrode are provided from an edge of a region facing a recess to an outside of the recess, the first electrode is formed between the second electrode and the third electrode, and the fourth electrode configures a common electrode for the plurality of active portions.

A piezoelectric device includes a substrate on which a plurality of recesses are arranged in a first direction, a vibration plate, and a piezoelectric actuator having a first electrode, a second electrode and a third electrode, a fourth electrode, and a piezoelectric layer, in which a plurality of active portions are provided, the second electrode and the third electrode are provided from an edge of a region facing a recess to an outside of the recess, the first electrode is formed between the second electrode and the third electrode, the second electrode, the third electrode, and the fourth electrode configure common electrodes for the plurality of active portions, and the first electrode configures an individual electrode provided independently for each of the active portions.

A cooling system and method for using the cooling system are described. The cooling system includes a plurality of individual piezoelectric cooling elements spatially arranged in an array extending in at least two dimensions, a communications interface and driving circuitry. The communications interface is associated with the individual piezoelectric cooling elements such that selected individual piezoelectric cooling elements within the array can be activated based at least in part on heat energy generated in the vicinity of the selected individual piezoelectric cooling elements. The driving circuitry is associated with the individual piezoelectric cooling elements and is configured to drive the selected individual piezoelectric cooling elements.

A cooling system and method for using the cooling system are described. The cooling system includes a plurality of individual piezoelectric cooling elements spatially arranged in an array extending in at least two dimensions, a communications interface and driving circuitry. The communications interface is associated with the individual piezoelectric cooling elements such that selected individual piezoelectric cooling elements within the array can be activated based at least in part on heat energy generated in the vicinity of the selected individual piezoelectric cooling elements. The driving circuitry is associated with the individual piezoelectric cooling elements and is configured to drive the selected individual piezoelectric cooling elements.