Abstract: A motion amplifier (22) comprises piezoelectric diaphragm (30) and drive electronics (26) for applying a drive signal to the piezoelectric diaphragm. The motion amplifier preferably comprises (in addition to the piezoelectric diaphragm) a reaction mass (34) connected to the piezoelectric diaphragm; a reacted mass (40) connected to the piezoelectric diaphragm; and, a reacted mass spring (50, 270) for resiliently carrying the reacted mass. Motion or displacement of the piezoelectric diaphragm (30) is amplified to produce a greater displacement or motion of an actuator region or surface (46) of the reacted mass (40).

Abstract: An example embodiment of an energy harvesting device (20) comprising a piezoelectric element (30) provides two degrees of vibration freedom for the piezoelectric element and magnetic soft impact, thereby enhancing power output of the piezoelectric element. The example embodiment of an energy harvesting device (20) comprises a frame (22); a body (28) configured to oscillate with respect to the frame upon vibration of the frame; a piezoelectric member (30); and, at least one frame magnet (32) mounted on the frame (22) and at least one body magnet (34) mounted on the body (28). The piezoelectric element (30) is connected to the body and configured to undergo deflection upon oscillation of the body (28), and upon the deflection to generate an electrical voltage. The frame magnet (32) and the body magnet (34) are of opposite polarity with one another and positioned to create a repulsive force between the frame (22) and the body (28).

Abstract: A thermal transfer device (20) comprises a housing having a base assembly (23) and a cover (22). The base assembly (23) comprises a thermal transfer base (25) and a fluid-porous, thermally conductive mesh structure (26). The thermal transfer base (25) and the cover (22) cooperate to define a thermal transfer chamber (24). The thermally conductive mesh structure (26) is configured and positioned in the chamber (24) to provide a tortuous, thermal conduction path for fluid (e.g., a coolant) which turbulently travels from an inlet (40) of the chamber to one or more outlets (42) of the chamber (24). In some embodiments, the mesh structure comprises wires which are fused by diffusion bonding into a mesh, in other embodiments the mesh comprises a metallic wool. Within the chamber the mesh structure (26) can have various configurations for providing an exposure interface between fluid pumped through the chamber and the mesh.

Abstract: A diaphragm assembly (20) comprises at least two piezoelectric diaphragm members (22) arranged in a stacking direction (23). An interface layer (24) is situated between adjacent piezoelectric diaphragm members (22). The interface layer (24) in the stacking direction (23) is displaceable and incompressible or resilient. The interface layer (24) permits lateral movement of the adjacent piezoelectric diaphragm members (22) relative to the interface layer (24) in a direction perpendicular to the stacking direction (23). The interface layer (24) can comprise, for example, an incompressible liquid or a semi-liquid or a compressible gas. A gasket (26) can be used to seal the substance in the interface layer if necessary.

Abstract: A piezoelectric element comprises a piezoelectric ceramic wafer bonded to a substrate, with a surface profile of the substrate being non-uniformly configured to affect the spring rate of the piezoelectric element. For example, in one example embodiment the substrate has its profile configured so that its stiffness is modified or non-uniform along at least one axis of the substrate. The nature of the non-uniform surface profile can acquire various configurations or patterns.

Abstract: An actuator assembly comprises a first diaphragm (422) and a second diaphragm (424) connected to the first diaphragm for forming a chamber (426) between the first diaphragm and the second diaphragm. An actuator shaft (427) is connected to first diaphragm (422) and is oriented to extend through the chamber (426) and to extend through an aperture formed in the second diaphragm (424). The second diaphragm (424) can be connected to an actuator body (450) wherein the actuator shaft (427) performs an actuation operation. Alternatively, one or more actuator amplification assemblies (400(B)) can be interposed between the second diaphragm and the actuator body.

Abstract: A synthetic jet comprises structure (comprising at least one piezoelectric member) for defining a fluid chamber; a nozzle configured to provide fluid communication between the fluid chamber and external to the fluid chamber; and, a drive source connected to apply an electrical signal to the piezoelectric member in a manner whereby activation of the piezoelectric member causes zero net flux of fluid with respect to the fluid chamber.

Abstract: An energy scavenging apparatus comprises a frame which can be human-carried or human-borne; plural cantilevered bimorph piezoelectric members connected to the frame to have an essentially parallel orientation, each cantilevered bimorph piezoelectric member comprising a proximal end connected to the frame and a distal end; and, a mass member connected to the distal end of the plural cantilevered bimorph piezoelectric members.

Abstract: A pump comprises a diaphragm assembly which includes a first diaphragm (22) having a first diaphragm edge (28) and a second diaphragm (24) having a second diaphragm edge (30). The first diaphragm edge (28) and the second diaphragm edge (30) are bonded together so that a bellows chamber (26) is formed between the first diaphragm (22) and the second diaphragm (24). At least one and possibly both of the first diaphragm (22) and the second diaphragm (24) is a piezoelectric diaphragm which displaces in accordance with application of an electrical signal. A driver applies the electrical signal to whichever of the first diaphragm (22) and the second diaphragm (24) is the piezoelectric diaphragm. The first diaphragm and the second diaphragm bow outwardly together and shrink in diameter during a suction stroke but flatten out and increase in diameter during a pump stroke.

Abstract: A drive circuit (18) produces a drive signal for a pump (10) having a piezoelectric actuator (14), with the piezoelectric actuator (14) forming a part of the drive circuit (18) and serving to shape a waveform of the drive signal. The drive circuit (18) comprises a pulse generator (100) which generates pulses; a converter circuit (102) which receives the pulses and produces charge packets at a rate which equals a desired drive frequency; and, the piezoelectric actuator (14). The piezoelectric actuator (14) receives the charge packets and, by its capacitive nature, integrates the charge packets to shape the waveform of the drive signal. Preferably, the piezoelectric actuator (14) integrates the charge packets to yield a drive field that approximates a sine wave. In one non-limiting example embodiment, the pulse generator (100) comprises a microcontroller-based pulsed width modulator (PWM) circuit (116) and the converter circuit (102) comprises a flyback circuit.

Abstract: A drive circuit (18) senses a parameter of a piezoelectric actuator (14) operating in a device (10) and adjusts a drive signal of the piezoelectric actuator in accordance with the parameter. The drive circuit comprises a controller (100) which controls a drive signal applied to the piezoelectric actuator (14); a feedback monitor (122) which obtains a feedback signal from the piezoelectric actuator while the piezoelectric actuator works; and, a processor (116) which uses the feedback signal to determine the parameter of the piezoelectric actuator. In one example mode, the parameter of the piezoelectric actuator which is determined by the piezoelectric actuator drive circuit is the capacitance or dielectric constant of the piezoelectric actuator. In other example modes, the parameter of the piezoelectric actuator which is determined by the piezoelectric actuator drive circuit is impedance or resonant frequency of the piezoelectric actuator.

Abstract: A drive circuit (18) senses a parameter of a piezoelectric actuator (14) operating in a device (10) and adjusts a drive signal of the piezoelectric actuator in accordance with the parameter. The drive circuit comprises a controller (100) which controls a drive signal applied to the piezoelectric actuator (14); a feedback monitor (122) which obtains a feedback signal from the piezoelectric actuator while the piezoelectric actuator works; and, a processor (116) which uses the feedback signal to determine the parameter of the piezoelectric actuator. In one example mode, the parameter of the piezoelectric actuator which is determined by the piezoelectric actuator drive circuit is the capacitance or dielectric constant of the piezoelectric actuator. In other example modes, the parameter of the piezoelectric actuator which is determined by the piezoelectric actuator drive circuit is impedance or resonant frequency of the piezoelectric actuator.

Abstract: A motion amplifier (22) comprises piezoelectric diaphragm (30) and drive electronics (26) for applying a drive signal to the piezoelectric diaphragm. The motion amplifier preferably comprises (in addition to the piezoelectric diaphragm) a reaction mass (34) connected to the piezoelectric diaphragm; a reacted mass (40) connected to the piezoelectric diaphragm; and, a reacted mass spring (50, 270) for resiliently carrying the reacted mass. Motion or displacement of the piezoelectric diaphragm (30) is amplified to produce a greater displacement or motion of an actuator region or surface (46) of the reacted mass (40).

Abstract: A motion amplification apparatus taking the form of a reverse vibration absorber (RVA) comprises a piezoelectric diaphragm (22); a driving diaphragm (26) configured to serve as a driving member for an actuated device (34); a mass (28) attached to the driving diaphragm (26); and, a resilient member (30) configured to connect the piezoelectric diaphragm (22) and the driving diaphragm (26) whereby motion of the piezoelectric diaphragm (22) resulting from application of the drive signal is amplified for driving the actuated device (34). The piezoelectric diaphragm (22) has a drive signal applied thereto and is held stationary around at least a portion of its periphery. The driving diaphragm (26) is also held stationary around at least a portion of its periphery.

Abstract: A drive circuit (18) produces a drive signal having a waveform of a predetermined waveform shape for a device (10) having a piezoelectric actuator (14). The drive circuit (14) includes a memory (140) which stores waveform shape data which is utilized by the drive circuit in producing the drive signal. The drive circuit utilizes the waveform shape data so that, for each of plural points comprising a period of the waveform, the drive signal has an appropriate amplitude for the predetermined waveform shape. The waveform shape data has preferably been prepared to optimize one or more operational parameter(s) of the device. Preferably the waveform shape data has been prepared by solving a waveform equation, the waveform equation having coefficients determined to optimize at least one operational parameter of the device.

Abstract: Actuator assemblies comprise an actuator element and two piezoelectric assemblies, with the two piezoelectric assemblies being configured and arranged for controlling movement of the actuator element. In some example implementations, the first piezoelectric assembly and the second piezoelectric assembly are constructed and arranged so that a temperature dependency of the first piezoelectric assembly is cancelled by the temperature dependency of the second piezoelectric assembly. In a first example embodiment, a first piezoelectric assembly comprises a first or main piezoelectric diaphragm connected to the actuator element for displacing the actuator element in response to displacement of the first piezoelectric diaphragm. The first piezoelectric diaphragm and the second piezoelectric diaphragm are fixedly mounted to a movable carriage.

Abstract: A pump comprises a body for at least partially defining a pumping chamber (28); a pump member which undergoes displacement when acting upon a fluid in the pumping chamber; and a piezoelectric element which responds to the displacement of the pump member to generate an electric current. The electric current generated by the piezoelectric element is preferably applied to a charge storage device which is coupled to the piezoelectric element. The storage device can take various forms, including but not limited to a battery (50, 150, 250), a capacitor (52, 152, 252), and a power supply for the pump (54). In one example embodiment, the pump member is a diaphragm (26) which undergoes the displacement when acting upon a fluid in the pumping chamber. In this example embodiment, the piezoelectric element responds to the displacement of the diaphragm to generate the electric current.