Abstract: This paper presents a microfluidic pumping approach using traveling-wave dielectrophoresis (tw-DEP) of microparticles. Flow is generated directly in the microfluidic devices by inducing electromechanical effects in the fluid using microelectrodes. The fluidic driving mechanisms due to the particle-fluid and particle-particle interactions under twDEP are analyzed, and the induced flow field is obtained from numerical simulations. Experimental measurements of the flow velocity in a prototype DEP micropumping device show satisfactory agreement with the numerical predications.

Abstract: A method to bond carbon nanotubes to a surface. The mechanism of this bonding is studied, and shows that intercalation of alkali ions is possibly the central mechanism. Bonding pull-off forces of 4-5 N/cm2 were measured. This bonding also provides improved interfacial properties for other phenomenon, including improved thermal conductivity.

Abstract: Apparatus and methods for controllably wetting a microstructured surface.

Abstract: A micropump including one or more microchannels for receiving a fluid and a plurality of electrodes arranged on a diaphragm and energized in a manner to provide an enhanced electrohydrodynamic flow of fluid through the one or more microchannels. The micropump may be used for pumping a working fluid for removing heat from a heat-generating electronic component or for delivery of a drug, medicine, or other treatment agent as or in a fluid to a patient.

Abstract: Control and switching of liquid droplet states on artificially structured surfaces have applications in the field of microfluidics. The present work introduces the concept of using structured surfaces consisting of non-communicating (closed cell) roughness elements to prevent the transition of a droplet from the Cassie to the Wenzel state (which would result in the irreversible loss of the superhydrophobic non-wetting properties of the surface). The use of non-communicating roughness elements leads to a confinement of the medium under the droplet in its Cassie state. Transition to the Wenzel state on such surfaces many include expulsion of this confined medium, which offers increased resistance to the Wenzel transition unlike surfaces consisting of communicating (open cell) roughness elements.

Abstract: A method to bond carbon nanotubes to a surface. The mechanism of this bonding is studied, and shows that intercalation of alkali ions is possibly the central mechanism. Bonding pull-off forces of 4-5 N/cm2 were measured. This bonding also provides improved interfacial properties for other phenomenon, including improved thermal conductivity.

Abstract: A method, apparatus, and system are described for an ionic wind generator. The ionic wind generator may have a first electrode that is elevated off a surface of a device that the ionic wind generator is intended to cool. A first surface of the first electrode is in contact with a first surface of a first post that elevates the first electrode off the surface of the device that the ionic wind generator is intended to cool. The ionic wind generator causes a generation of ions that are then drawn through an interstitial atmosphere from the first electrode to a second electrode to affect a velocity of local flow over the surface of the device between the first electrode and the second electrode. The flow from a forced flow device also affects the velocity of local flow over the surface of the device between the first electrode and the second electrode.

Abstract: This paper presents a microfluidic pumping approach using traveling-wave dielectrophoresis (tw-DEP) of microparticles. Flow is generated directly in the microfluidic devices by inducing electromechanical effects in the fluid using microelectrodes. The fluidic driving mechanisms due to the particle-fluid and particle-particle interactions under twDEP are analyzed, and the induced flow field is obtained from numerical simulations. Experimental measurements of the flow velocity in a prototype DEP micropumping device show satisfactory agreement with the numerical predications.

Abstract: A method, apparatus, and system are described for an ionic wind generator. The ionic wind generator may have a first electrode that is elevated off a surface of a device that the ionic wind generator is intended to cool. A first surface of the first electrode is in contact with a first surface of a first post that elevates the first electrode off the surface of the device that the ionic wind generator is intended to cool. The ionic wind generator causes a generation of ions that are then drawn through an interstitial atmosphere from the first electrode to a second electrode to affect a velocity of local flow over the surface of the device between the first electrode and the second electrode.

Abstract: A microchannel heat sink as well as method includes one or more microchannels through which a working fluid flows to remove heat from a heat-generating component, such as a microelectronic chip, and one or more recesses disposed in a surface communicated to the one or more of the microchannel to enhance heat transfer rate of the microchannel heat sink. The recesses can be located in a surface of a cover that closes off the microchannels. The one or more recesses can be located at one or more local hot spot regions to enhance heat transfer rates at the local regions as well as overall heat removal rate of the heat sink.

Abstract: A piezoelectric device, such as a piezoelectric fan or microjet generator, for moving a fluid comprising a fluid-moving member having a first piezoelectric (PZT) actuator element coupled thereto to drive or actuate the movable member and a second piezoelectric (PZT) sensing element coupled thereto to provide feedback information related to fluid parameter. The second PZT element also can be used to drive the movable member in conjunction with the first PZT element. The feedback information can be used by a controller to control operation of the piezoelectric device.

Abstract: Device for generating one or more cooling air jets comprising a housing having at least one aperture having an axis defining an air flow direction. A piezoelectrically actuated air-moving member is disposed in the housing transverse to the axis of the aperture to move toward and away from the aperture. A source of periodic alternating voltage signals is provided to actuate the piezoelectrically actuated air-moving member in a manner that periodic jets of air are discharged through the one or more apertures in the air flow direction.

Abstract: A piezoelectric device, such as a piezoelectric fan or microjet generator, for moving a fluid comprising a fluid-moving member having a first piezoelectric (PZT) actuator element coupled thereto to drive or actuate the movable member and a second piezoelectric (PZT) sensing element coupled thereto to provide feedback information related to fluid parameter. The second PZT element also can be used to drive the movable member in conjunction with the first PZT element. The feedback information can be used by a controller to control operation of the piezoelectric device.