A piezoelectric blower includes a valve, a housing, a vibrating plate, and a piezoelectric element. The vibrating plate forms, together with the housing, a column-shaped blower chamber such that the blower chamber is interposed therebetween in a thickness direction of the vibrating plate. The vibrating plate and the housing are formed such that the blower chamber has a radius (a). The piezoelectric element causes the vibrating plate to undergo concentric bending vibration at a resonance frequency (f). The radius (a) of the blower chamber and the resonance frequency (f) of the vibrating plate satisfy a relationship of 0.8(k.sub.0c)/(2)af1.2(k.sub.0c)/(2), where an acoustic velocity of gas that passes through the blower chamber is (c) and a value that satisfies a relationship of a Bessel function of a first kind of J.sub.0(k.sub.0)=0 is k.sub.0.

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.

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.

An electronic device may include an electronic circuit, a heat sink thermally coupled to the electronic circuit, and spaced apart cooling fins extending from the heat sink. Each cooling fin includes a circuit board and a cooling device mounted thereon. The cooling device may have a conductive trace layer on the circuit board defining an electromagnet, a mounting member extending upwardly from the circuit board, a fan blade coupled to an upper end of the mounting member to be movable in a rocking motion about an axis defined by the mounting member, and a permanent magnet carried by the fan blade and responsive to the electromagnet.

An electronic device may include an electronic circuit, a heat sink thermally coupled to the electronic circuit, and spaced apart cooling fins extending from the heat sink. Each cooling fin includes a circuit board and a cooling device mounted thereon. The cooling device may have a conductive trace layer on the circuit board defining an electromagnet, a mounting member extending upwardly from the circuit board, a fan blade coupled to an upper end of the mounting member to be movable in a rocking motion about an axis defined by the mounting member, and a permanent magnet carried by the fan blade and responsive to the electromagnet.

Embodiments of the present invention provide a heat dissipation apparatus. Wherein a loop coil is disposed on a swing plate. A first magnet and a second magnet are located on two sides of the loop coil, and when a current whose direction periodically varies flows through the loop coil, an Ampere force whose direction periodically varies is applied to the loop coil under an action of a magnetic field formed by the first magnet and the second magnet, so that the loop coil drives the swing plate to swing back and forth. The present invention is used for heat dissipation of a micro electronic component.

A jet flow generation device includes: a discharge electrode; a reference electrode that is disposed away from the discharge electrode; a power supply circuit that generates an output voltage to control a potential difference between the discharge electrode and the reference electrode; a controller that switches the output voltage of the power supply circuit between a first voltage that does not induce corona discharge between the discharge electrode and the reference electrode and a second voltage that induces corona discharge between the discharge electrode and the reference electrode; and a case housing at least the reference electrode has an injection port that injects an ion wind of ions generated by the corona discharge.

A jet flow generation device includes: a discharge electrode; a reference electrode that is disposed away from the discharge electrode; a power supply circuit that generates an output voltage to control a potential difference between the discharge electrode and the reference electrode; a controller that switches the output voltage of the power supply circuit between a first voltage that does not induce corona discharge between the discharge electrode and the reference electrode and a second voltage that induces corona discharge between the discharge electrode and the reference electrode; and a case housing at least the reference electrode has an injection port that injects an ion wind of ions generated by the corona discharge.

A driving system for an actuating and sensing module includes an actuating and sensing device and a power supply device. The actuating and sensing device includes a sensor, an actuating device, a microprocessor, and a power controller. The power supply device transfers an energy to the power controller, thereby enabling the sensor and the actuating device.

A flapping fan for cooling electronic devices includes an elongated piezo actuator, two supporting members, two connecting members, and a thin blade. The supporting members are attached to the piezo actuator at its two ends, while the blade is connected to the piezo actuator through the connecting members. When activated by an AC signal, the piezo actuator oscillates around its neutral position, which causes the blade to oscillate. The blade rotates around its leading edge when its direction of motion changes, keeping its angle of incidence lower than ninety degrees. This helps the flapping fan to generate a significant air flow.