A pump is provided with a pump housing, a vibrating portion, a driving portion, and a displacement regulating portion. The pump housing internally has a pump chamber. The vibrating portion is supported against the pump housing in the pump chamber and divides the pump chamber into a first pump chamber and a second pump chamber. The driving portion drives the vibrating portion so as to bend and vibrate the vibrating portion in a predetermined direction. The displacement regulating portion is positioned to prevent displacement of the vibrating portion that results in plastic deformation.

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 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 hydraulic fracturing system can include valve apparatuses that control the delivery of fluid to high-pressure pumps that supply the fluid to a wellhead. The valve apparatuses can receive electronic signals from a control system to regulate the flow rate of the fluid to the high-pressure pumps. In one or more examples, the flow rate of the fluid can be controlled such that proppant in the fluid remains in solution.

Disclosed is a flow device including an inlet, an outlet, and a plurality of fluid flow paths hydraulically connected in parallel to the inlet and the outlet, wherein the plurality of fluid flow paths forms a first ring of fluid flow paths circumferentially arranged at a first radial distance from a centerline of the fluid flow device a second ring of fluid flow patch circumferentially arranged at a second radial distance from the centerline of the fluid flow device, each of the plurality of fluid flow paths has a first hydraulic resistance in a forward flow direction and a second hydraulic resistance in a reverse flow direction, and the second hydraulic resistance is greater than the first hydraulic resistance.

A fluid pump is shown, comprising: a chamber comprising an inlet and an outlet, the outlet comprising a non-return valve, the chamber having a cavity comprising a cylinder; a piston slidably disposed within the cylinder; and a Tesla valve in fluid communication with the inlet, wherein the fluid pump is configured to pump fluid from the inlet to the outlet by reciprocation of the piston within the cylinder.

A piezoelectric cooling chamber and method for providing the cooling system are described. The cooling chamber includes a piezoelectric cooling element, an array of orifices and a valve. A vibrational motion of the piezoelectric cooling element causes an increase or decrease in a chamber volume as the piezoelectric cooling element is deformed. The array of orifices is distributed on at least one surface of the chamber. The orifices allow escape of fluid from within the chamber during the decrease in the chamber volume in response to the vibration of the piezoelectric element. The valve is configured to admit fluid into the chamber when the chamber volume increases and to substantially prevent fluid from exiting the chamber through the valve when the chamber volume decreases.

A hydraulic fracturing system can include valve apparatuses that control the delivery of fluid to high-pressure pumps that supply the fluid to a wellhead. The valve apparatuses can receive electronic signals from a control system to regulate the flow rate of the fluid to the high-pressure pumps. In one or more examples, the flow rate of the fluid can be controlled such that proppant in the fluid remains in solution.

An active cooling system and method for using the active cooling system are described. The active cooling system includes a cooling element having a first side and a second side. The first side of the cooling element is distal to a heat-generating structure and in communication with a fluid. The second side of the cooling element is proximal to the heat-generating structure. The cooling element is configured to direct the fluid using a vibrational motion from the first side of the cooling element to the second side such that the fluid moves in a direction that is incident on a surface of the heat-generating structure at a substantially perpendicular angle and then is deflected to move along the surface of the heat-generating structure to extract heat from the heat-generating structure.

A system for cooling a mobile phone and method for using the system are described. The system includes an active piezoelectric cooling system, a controller and an interface. The active piezoelectric cooling system is configured to be disposed in a rear portion of the mobile phone distal from a front screen of the mobile phone. The controller is configured to activate the active piezoelectric cooling system in response to heat generated by heat-generating structures of the mobile phone. The interface is configured to receive power from a mobile phone power source when the active piezoelectric cooling system is activated.