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 microfabricated fluid pump is formed in a multilayer substrate by etching a plurality of shallow and deep wells into the layers, and then joining these wells with voids formed by anisotropic etching. The voids define a flexible membrane over the substrate which deforms when a force is applied. The force may be provided by an embedded layer of piezoelectric material. Embedded strain gauges may allow self-sensing and convenient, precise operational control.

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 negative pressure wound therapy device includes a piezoelectric pump, a state detector configured to detect a state of the pump, and a control circuit configured to transmit a first control signal for a first period having a first RMS voltage greater than or equal to a threshold voltage at which driving the pump for a second period greater than the first period can cause the pump to emit sound at a magnitude greater than a sound threshold; receive a first indication of the state; determine if the pump is in a leak condition; transmit, responsive to the pump not being in the leak condition, a second control signal having a second RMS voltage less than the first RMS voltage; and transmit, responsive to the pump being in the leak condition, a third control signal having a third RMS voltage greater than the second RMS voltage.

A liquid material ejection device in which a plunger is efficiently accelerated. The device includes a liquid chamber communicating with an ejection port and being supplied with a liquid material, a plunger including a tip portion having a smaller diameter than the liquid chamber and is moved in the liquid chamber, an elastic member urging the plunger upward, an arm disposed in a state extending in a substantially horizontal direction, an arm driver serving as a driving source to operate the arm, and a base member on which the arm driver is disposed. The device further includes a rocking mechanism unit connected to the arm driver and rockingly supporting the arm, the arm driver includes a plurality of actuators, the arm includes a pressing portion pressing the plunger downward, the plunger is pressed by the pressing portion, and the plunger is linearly reciprocated with rocking motion of the arm.

A power driver of an unmanned aerial vehicle is disclosed and includes a main body, a fluid actuation system and a controller, wherein the fluid actuation system includes a driving zone, a converging chamber, a plurality of valves and a fluid discharging zone. The driving zone includes a plurality of flow guiding units which arranged in series, parallel or series-parallel, each of the flow guiding unit generates an inside pressure gradient after being actuated, so as to inhale fluid and diverge fluid by guiding channels, and flow into the convergence chamber for storage, wherein the amount of the fluid transported is controlled by the plurality of valves disposed in the connection channels through the controller, and fluid is finally converged to the fluid discharging zone for discharging the specific transportation amount of fluid.

A fluid control device includes a piezoelectric pump, a piezoelectric pump, a container, and a control unit. The piezoelectric pumps and are connected in series. The piezoelectric pump is an upstream-side pump, and the piezoelectric pump is a downstream-side pump. The control unit controls driving of the piezoelectric pumps. The control unit makes the driving start timing of the piezoelectric pump on an upstream side earlier than the driving start timing of the piezoelectric pump on a downstream side.

The present invention is a piezoelectric actuator drive method, a piezoelectric actuator drive circuit, and a piezoelectric actuator drive system capable of causing a piezoelectric element to vibrate in a maximum amplitude state. The piezoelectric actuator drive circuit includes: an obtainment unit that obtains operation information pertaining to operation of the piezoelectric element in a period that is a part of one cycle of a drive cycle in which the piezoelectric element is driven; and a control unit that performs feedback control of a drive parameter for driving the piezoelectric element based on the operation information.

A piezoelectric element drive circuit includes a piezoelectric element driven at a predetermined frequency and having a resonant frequency of (2n+1) times the predetermined frequency (n is a predetermined natural number), and a drive voltage generator that has a first output terminal connected to a first terminal of the piezoelectric element and a second output terminal connected to a second terminal of the piezoelectric element. When the piezoelectric element is driven, a waveform of potential difference between the first output terminal and the second output terminal is a step wave which transitions while taking an intermediate potential. A time length for which the potential difference is the intermediate potential is around (t2−t1)/(2n+1) in a period of time from time t.sub.1 at which the potential difference falls to the intermediate potential to time t.sub.2 at which the potential difference falls to the intermediate potential subsequently.

A case for an electronic cigarette vaporiser, the case including an automatic lifting mechanism that lifts the vaporiser up a few mm from the case to enable a user to easily grasp the vaporiser and withdraw it from the case. The lifting mechanism can be spring-based. The case both re-fills the vaporiser with liquid and also re-charges a battery in the vaporiser.