Abstract: The present disclosure relates to a novel absorbance-based colorimetric device system, and to methods of using the novel absorbance-based colorimetric device system.

Abstract: Systems and methods that utilize enhanced boiling surfaces to promote the efficiency of boiling. Such a system has a surface that is hydrophobic and exhibits a sufficiently low receding contact angle to a liquid such that vapor spreading during bubble growth and premature transition to film boiling is mitigated.

Abstract: The present disclosure relates to a novel absorbance-based colorimetric device system, and to methods of using the novel absorbance-based colorimetric device system.

Abstract: Systems and methods that utilize enhanced boiling surfaces to promote the efficiency of boiling. Such a system has a surface that is hydrophobic and exhibits a sufficiently low receding contact angle to a liquid such that vapor spreading during bubble growth and premature transition to film boiling is mitigated.

Abstract: Permeable membrane microchannel heat sinks and methods of producing such a heat sink, wherein such a heat sink includes a base and at least first and second microchannels defined by at least one porous and permeable membrane that is on the base and defines primary heat exchange surfaces of the heat sink. The membrane has opposing faces exposed to the first and second microchannels, and a fluid flowing through the heat sink flows from the first microchannel to the second microchannel through pores in the membrane.

Abstract: An apparatus and a method of enhancing boiling heat transfer therein capable of increasing both the critical heat flux and nucleate boiling heat transfer of a working fluid. The method includes placing free particles on a surface so as to define narrow corner gaps and cavities at interfaces between the particles and the surface and heating the surface while the surface is contacted by the working fluid to bring the working fluid to a boil, with the result that bubble nucleation is facilitated and nucleate boiling heat transfer from the surface is increased.

Abstract: Vapor chambers suitable for applications with power densities of one kW/cm2 or greater over a heat input area of one cm2 or greater and methods of manufacturing the same are provided. The vapor chambers include a housing having a thermally conductive substrate, a working fluid contained within the housing, a base layer formed of a porous thermally conductive material and located on and in thermal contact with the substrate, a cap layer formed of a porous thermally conductive material having through-holes formed therein defining vapor vents, and a plurality of conduits connecting the cap layer and the base layer with interstitial gaps therebetween. The conduits are capable of conveying the working fluid from the cap layer to the base layer. Heat entering the base layer causes the working fluid to evaporate from the base layer and the base layer is replenished with the working fluid through the conduits.

Abstract: Methods and apparatuses for detection of gas bubbles in a microchannel configured for a conductive fluid to flow therethrough. The methods and apparatuses utilize a plate and at least two aligned electrodes embedded within the plate. The plate is configured to be located over the microchannel such that the at least two aligned electrodes are located along a length of the microchannel in the flow direction. Impedance is measured between the electrodes, and the percentage of gas within the fluid flowing through the microchannel is measured based on the measured impedance between the electrodes.

Abstract: Materials, apparatuses, and methods that are suitable for separating immiscible liquids and make use of a porous host material functionalized with a functionalizing agent such that the host material is superhydrophobic.

Abstract: Modular cooling apparatuses are disclosed. In one embodiment, a cooling apparatus includes an inlet manifold, a jet plate manifold, a plurality of jet plates, a vapor manifold, and a target layer. The inlet manifold includes a fluid distribution chamber, and a plurality of fluid distribution channels symmetrically located within the fluid distribution chamber. The jet plate manifold is coupled to the inlet manifold such that the plurality of jet plate openings is vertically aligned with respect to the plurality of fluid distribution channels. The plurality of jet plates is removably disposed in the jet plate manifold. The vapor manifold has a plurality of walls that define a vapor manifold opening and at least one outlet channel through at least one of the walls. The target layer is coupled to the vapor manifold such that the jet orifice surface of each jet plate is positioned above the target layer.

Abstract: Methods and apparatuses for detection of gas bubbles in a microchannel configured for a conductive fluid to flow therethrough. The methods and apparatuses utilize a plate and at least two aligned electrodes embedded within the plate. The plate is configured to be located over the microchannel such that the at least two aligned electrodes are located along a length of the microchannel in the flow direction. Impedance is measured between the electrodes, and the percentage of gas within the fluid flowing through the microchannel is measured based on the measured impedance between the electrodes.

Abstract: An apparatus and a method of enhancing boiling heat transfer therein capable of increasing both the critical heat flux and nucleate boiling heat transfer of a working fluid. The method includes placing free particles on a surface so as to define narrow corner gaps and cavities at interfaces between the particles and the surface and heating the surface while the surface is contacted by the working fluid to bring the working fluid to a boil, with the result that bubble nucleation is facilitated and nucleate boiling heat transfer from the surface is increased.

Abstract: Jet-impingement, two-phase cooling apparatuses and power electronics modules having a target surface with single- and two-phase surface enhancement features are disclosed. In one embodiment, a cooling apparatus includes a jet plate surface and a target layer. The jet plate surface includes a jet orifice having a jet orifice geometry, wherein the jet orifice is configured to generate an impingement jet of a coolant fluid. The target layer has a target surface, single-phase surface enhancement features, and two-phase surface enhancement features. The target surface is configured to receive the impingement jet, and the single-phase surface enhancement features and the two-phase enhancement features are arranged on the target surface according to the jet orifice geometry.

Abstract: Jet-impingement, two-phase cooling apparatuses and power electronics modules having a target surface with single- and two-phase surface enhancement features are disclosed. In one embodiment, a cooling apparatus includes a jet plate surface and a target layer. The jet plate surface includes a jet orifice having a jet orifice geometry, wherein the jet orifice is configured to generate an impingement jet of a coolant fluid. The target layer has a target surface, single-phase surface enhancement features, and two-phase surface enhancement features. The target surface is configured to receive the impingement jet, and the single-phase surface enhancement features and the two-phase enhancement features are arranged on the target surface according to the jet orifice geometry.

Abstract: Modular cooling apparatuses are disclosed. In one embodiment, a cooling apparatus includes an inlet manifold, a jet plate manifold, a plurality of jet plates, a vapor manifold, and a target layer. The inlet manifold includes a fluid distribution chamber, and a plurality of fluid distribution channels symmetrically located within the fluid distribution chamber. The jet plate manifold is coupled to the inlet manifold such that the plurality of jet plate openings is vertically aligned with respect to the plurality of fluid distribution channels. The plurality of jet plates is removably disposed in the jet plate manifold. The vapor manifold has a plurality of walls that define a vapor manifold opening and at least one outlet channel through at least one of the walls. The target layer is coupled to the vapor manifold such that the jet orifice surface of each jet plate is positioned above the target layer.

Abstract: Jet-impingement, two-phase cooling apparatuses and power electronics modules having a target surface with single- and two-phase surface enhancement features are disclosed. In one embodiment, a cooling apparatus includes a jet plate surface and a target layer. The jet plate surface includes a jet orifice having a jet orifice geometry, wherein the jet orifice is configured to generate an impingement jet of a coolant fluid. The target layer has a target surface, single-phase surface enhancement features, and two-phase surface enhancement features. The target surface is configured to receive the impingement jet, and the single-phase surface enhancement features and the two-phase enhancement features are arranged on the target surface according to the jet orifice geometry.

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

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: 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.