Provided are a fluid control device capable of operating a piezoelectric pump even in a case where a low discharge pressure or a slow pressurization speed is required and a sphygmomanometer including the fluid control device. A fluid control device includes a piezoelectric pump that includes a piezoelectric element, a self-excited circuit that performs, upon application of a driving power source voltage thereto, self-excited oscillation to drive the piezoelectric element, a switch that interrupts the driving power source voltage for the self-excited circuit, and a control circuit that changes an on duty ratio of the self-excited circuit by switching between states of the switch at a predetermined switching frequency and a predetermined on duty ratio.

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.

Micropump (10) including a support structure (14), a pump tube (16), and an actuation system (18) comprising one or more pump chamber actuators (28), the pump tube comprising a pump chamber portion (24) defining therein a pump chamber (26), an inlet portion (20) for inflow of fluid into the pump chamber, and an outlet portion (22) for outflow of fluid from the pump chamber. The inlet, outlet and pump chamber portions form part of a continuous section of tube made of a supple material. The one or more pump chamber actuators are configured to bias against the pump chamber portion to expel liquid contained in the pump chamber via the outlet portion, respectively to bias away from the pump chamber portion to allow liquid to enter the pump chamber via the inlet portion. The pump chamber portion has a cross-sectional area Ap in an expanded state that is larger than a cross-sectional area Ai of the pump tube at the inlet and outlet portions.

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.

A pump includes a vibrating plate having a piezoelectric body on a first main surface, a cover including a top panel and a side wall, the top panel opposing a second main surface of the vibrating plate opposite to the first main surface, the top panel having a first cavity, and the side wall being connected to an outer peripheral portion of the top panel to surround a space between the top panel and the vibrating plate, a support portion connected to the side wall and supporting an outer periphery of the vibrating plate, and a second cavity formed between the side wall and the vibrating plate in a cross-sectional view in a direction orthogonal to a direction in which the second main surface of the vibrating plate and a main surface of the top panel oppose each other.

A piezoelectric actuator includes a deflectable membrane and a piezoelectric element attached to a part of the deflectable membrane for exerting a mechanical force on the deflectable membrane. The piezoelectric element is operable to perform an expansion and a contraction motion depending on an electric field applied to the piezoelectric element. The piezoelectric element leaves open a central region of the deflectable membrane and has a peripheral outline that does not coincide with an outline of the deflectable membrane.

An example pump for driving a biological fluid is described herein. The pump can include an inner tubular structure and an outer tubular structure arranged around the inner tubular structure. The outer tubular structure can be configured as an artificial muscle. The pump can also include a gel layer disposed between the inner and outer tubular structures.

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.

A pump includes a vibrating plate having a piezoelectric body on a first main surface, a cover including a top panel and a side wall, the top panel opposing a second main surface of the vibrating plate opposite to the first main surface, the top panel having a first cavity, and the side wall being connected to an outer peripheral portion of the top panel to surround a space between the top panel and the vibrating plate, a support portion connected to the side wall and supporting an outer periphery of the vibrating plate, and a second cavity formed between the side wall and the vibrating plate in a cross-sectional view in a direction orthogonal to a direction in which the second main surface of the vibrating plate and a main surface of the top panel oppose each other.