Abstract: Improved cooling performance is provided using a two-phase cooler designed such that most of the coolant evaporates and condenses in operation. The evaporator includes microchannels and a hydrophilic surface structure to enhance capillary-driven flow by wicking. Coolant vapor hitting the condenser is condensed and recirculated to the evaporator. Preferably, this recirculation is in a sealed vapor chamber with no pumping of the coolant. A coolant flow structure can be included on top of the evaporator to facilitate coolant flow to hot spots on the evaporator and to facilitate vapor flow away from these hot spots.

Abstract: In one embodiment, a micro-cooler assembly includes a manifold having at least one inlet for receiving a liquid, a plurality of fins, wherein each fin of the plurality of fins includes a micro-channel, and a plurality of vapor gaps interlaced with the plurality of fins. A width of the micro-channels is graded, and/or a width of the vapor gaps is graded. The micro-cooler assembly further includes a cold plate that includes a surface and a wick region disposed on the surface. The manifold is coupled to the surface of the cold plate. The at least one inlet is operable to provide the liquid proximate the wick region. The liquid is operable to be wicked into the wick region through the micro-channels of the plurality of fins, and heating of the liquid changes phase to a vapor that exits the manifold through the plurality of vapor gaps.

Abstract: A first aspect of this work relates to water harvesting in power plants. A water adsorbent material is driven through adsorption-desorption cycles using waste heat from a power plant to harvest water from ambient air. In a preferred embodiment, metal-organic-framework (MOF) powders are used as the water adsorbent material for this application. A second aspect of this work relates more generally to rapid adsorption-desorption cycling of MOFs for various applications.

Abstract: Disclosed herein are apparatus for a cooler device includes a manifold constructed at least partially of silicon oxide. The manifold includes an array of inlet channels and an array of outlet channels. Each inlet channel has a first depth. The array of outlet channels are interlaced with the array of inlet channels, Each outlet channel has a second depth that is larger than the first depth. Each of the array of outlet channels has a pair of sidewalls separating each outlet channel from adjacent inlet channels of the array of inlet channels.

Abstract: Disclosed herein are apparatus for a cooler device includes a manifold constructed at least partially of silicon oxide. The manifold includes an array of inlet channels and an array of outlet channels. Each inlet channel has a first depth. The array of outlet channels are interlaced with the array of inlet channels, Each outlet channel has a second depth that is larger than the first depth. Each of the array of outlet channels has a pair of sidewalls separating each outlet channel from adjacent inlet channels of the array of inlet channels.

Abstract: Improved vapor chambers are provided using monolithic wick structures having deep features (?150 um) and two or more different feature heights above the substrate. Such monolithic multi-level wick structures provide improved performance in vapor chambers by alleviating the tradeoff between fluid transport (which favors tall pin-fins) and heat transfer (which favors short pin-fins).

Abstract: A cooler device includes a cold plate and a manifold with fluid wicking structure. The cold plate includes an array of bonding posts and an array of fluid channels. Each bonding post of the array of bonding posts has a first height and is in contact with the manifold with fluid wicking structure. Each fluid channel of the array of fluid channels has a second height that is less than the first height. The array of fluid channels include a MIO secondary wick structure. The array of bonding posts is orthogonal to the array of fluid channels. The manifold with fluid wicking structure includes a plurality of spacer elements and a plurality of mesh layers. Each one of the plurality of spacer elements alternate with each one of the plurality of mesh layers in a stacked arrangement.

Abstract: A cooler device includes a cold plate and a manifold with fluid wicking structure. The cold plate includes an array of bonding posts and an array of fluid channels. Each bonding post of the array of bonding posts has a first height and is in contact with the manifold with fluid wicking structure. Each fluid channel of the array of fluid channels has a second height that is less than the first height. The array of fluid channels include a MIO secondary wick structure. The array of bonding posts is orthogonal to the array of fluid channels. The manifold with fluid wicking structure includes a plurality of spacer elements and a plurality of mesh layers. Each one of the plurality of spacer elements alternate with each one of the plurality of mesh layers in a stacked arrangement.

Abstract: We provide a novel cleanroom-based process flow that allows for easy creation of multi-level, hierarchical 3D structures in a substrate. This is achieved by introducing an ultra-thin sacrificial hardmask layer on the substrate which is first 3D patterned via multiple rounds of lithography. This 3D pattern is then scaled vertically by a factor of 200 - 300 and transferred to the substrate underneath via a single shot deep etching step. This method is also easily characterizable - using features of different topographies and dimensions, the etch rates and selectivities were quantified; this characterization information was later used while fabricating specific target structures.

Abstract: A first aspect of this work relates to water harvesting in power plants. A water adsorbent material is driven through adsorption-desorption cycles using waste heat from a power plant to harvest water from ambient air. In a preferred embodiment, metal-organic-framework (MOF) powders are used as the water adsorbent material for this application. A second aspect of this work relates more generally to rapid adsorption-desorption cycling of MOFs for various applications.

Abstract: A low-power phase-change memory (PCM) technology with interfacial thermoelectric heating (TEH) enhancement is provided. Embodiments described herein leverage a substantial, positive thermoelectric coefficient in PCM materials to generate additional heating or cooling at an interface with another material, enabling memory switching with a large reduction in current and power. Interfacial thermoelectric engineering is applied to a PCM cell using a special class of thermoelectric materials with large negative Seebeck coefficients (e.g., bismuth telluride (Bi2Te3), lead telluride (PbTe), lanthanum telluride (La3Te4), indium selenide (InSe), silicon-germanium (Si0.8Ge0.2)) to induce efficient heating at significantly lowered power and current.

Abstract: A method of etching features in a silicon wafer includes coating a top surface and a bottom surface of the silicon wafer with a mask layer having a lower etch rate than an etch rate of the silicon wafer, removing one or more portions of the mask layer to form a mask pattern in the mask layer on the top surface and the bottom surface of the silicon wafer, etching one or more top surface features into the top surface of the silicon wafer through the mask pattern to a depth plane located between the top surface and the bottom surface of the silicon wafer at a depth from the top surface, coating the top surface and the one or more top surface features with a metallic coating, and etching one or more bottom surface features into the bottom surface of the silicon wafer through the mask pattern to the target depth plane.

Abstract: A method of etching features in a silicon wafer includes coating a top surface and a bottom surface of the silicon wafer with a mask layer having a lower etch rate than an etch rate of the silicon wafer, removing one or more portions of the mask layer to form a mask pattern in the mask layer on the top surface and the bottom surface of the silicon wafer, etching one or more top surface features into the top surface of the silicon wafer through the mask pattern to a depth plane located between the top surface and the bottom surface of the silicon wafer at a depth from the top surface, coating the top surface and the one or more top surface features with a metallic coating, and etching one or more bottom surface features into the bottom surface of the silicon wafer through the mask pattern to the target depth plane.

Abstract: A method of etching features in a silicon wafer includes coating a top surface and a bottom surface of the silicon wafer with a mask layer having a lower etch rate than an etch rate of the silicon wafer, removing one or more portions of the mask layer to form a mask pattern in the mask layer on the top surface and the bottom surface of the silicon wafer, etching one or more top surface features into the top surface of the silicon wafer through the mask pattern to a depth plane located between the top surface and the bottom surface of the silicon wafer at a depth from the top surface, coating the top surface and the one or more top surface features with a metallic coating, and etching one or more bottom surface features into the bottom surface of the silicon wafer through the mask pattern to the target depth plane.

Abstract: A method of etching features in a silicon wafer includes coating a top surface and a bottom surface of the silicon wafer with a mask layer having a lower etch rate than an etch rate of the silicon wafer, removing one or more portions of the mask layer to form a mask pattern in the mask layer on the top surface and the bottom surface of the silicon wafer, etching one or more top surface features into the top surface of the silicon wafer through the mask pattern to a depth plane located between the top surface and the bottom surface of the silicon wafer at a depth from the top surface, coating the top surface and the one or more top surface features with a metallic coating, and etching one or more bottom surface features into the bottom surface of the silicon wafer through the mask pattern to the target depth plane.

Abstract: A thermally-conductive and mechanically-robust bonding method for attaching a metal nanowire (MNW) array to an adjacent surface includes the steps of: removing a template membrane from the MNW; infiltrating the MNW with a bonding material; placing the bonding material on the adjacent surface; bringing an adjacent surface into contact with a top surface of the MNW while the bonding material is bondable; and allowing the bonding material to cool and form a solid bond between the MNW and the adjacent surface. A thermally-conductive and mechanically-robust bonding method for attaching a metal nanowire (MNW) array to an adjacent surface includes the steps of: choosing a bonding material based on a desired bonding process; and without removing the MNW from a template membrane that fills an interstitial volume of the MNW, depositing the bonding material onto a tip of the MNW.

Abstract: Embodiments of an evaporator chamber heat flux rectifier and thermal switch are provided. Some embodiments include an evaporator layer with a first thermally conductive surface, a wicking structure for facilitating evaporation of a fluid in the vapor chamber heat flux rectifier, and a condenser layer that includes a second thermally conductive surface. Some embodiments include a middle layer, where when heat is applied to the first thermally conductive surface, the vapor chamber heat flux rectifier operates as a thermal conductor. Some embodiments that operate as a thermal switch include a non-condensable gas reservoir that is coupled to the condenser layer. The non-condensable gas reservoir may store a non-condensable gas when a threshold heat flux is applied to the evaporator layer. The non-condensable gas provides thermal insulation between the evaporator layer and the condenser layer when the threshold heat flux is not applied to the evaporator layer.

Abstract: Embodiments of an evaporator chamber heat flux rectifier and thermal switch are provided. Some embodiments include an evaporator layer with a first thermally conductive surface, a wicking structure for facilitating evaporation of a fluid in the vapor chamber heat flux rectifier, and a condenser layer that includes a second thermally conductive surface. Some embodiments include a middle layer, where when heat is applied to the first thermally conductive surface, the vapor chamber heat flux rectifier operates as a thermal conductor. Some embodiments that operate as a thermal switch include a non-condensable gas reservoir that is coupled to the condenser layer. The non-condensable gas reservoir may store a non-condensable gas when a threshold heat flux is applied to the evaporator layer. The non-condensable gas provides thermal insulation between the evaporator layer and the condenser layer when the threshold heat flux is not applied to the evaporator layer.

Abstract: A thermally-conductive and mechanically-robust bonding method for attaching a metal nanowire (MNW) array to an adjacent surface includes the steps of: removing a template membrane from the MNW; infiltrating the MNW with a bonding material: placing the bonding material on the adjacent surface; bringing an adjacent surface into contact with a top surface of the MNW while the bonding material is bondable; and allowing the bonding material to cool and form a solid bond between the MNW and the adjacent surface. A thermally-conductive and mechanically-robust bonding method for attaching a metal nanowire (MNW) array to an adjacent surface includes the steps of: choosing a bonding material based on a desired bonding process; and without removing the MNW from a template membrane that fills an interstitial volume of the MNW, depositing the bonding material onto a tip of the MNW.

Abstract: A thermally-conductive and mechanically-robust bonding method for attaching a metal nanowire (MNW) array to an adjacent surface includes the steps of: removing a template membrane from the MNW; infiltrating the MNW with a bonding material; placing the bonding material on the adjacent surface; bringing an adjacent surface into contact with a top surface of the MNW while the bonding material is bondable; and allowing the bonding material to cool and form a solid bond between the MNW and the adjacent surface. A thermally-conductive and mechanically-robust bonding method for attaching a metal nanowire (MNW) array to an adjacent surface includes the steps of: choosing a bonding material based on a desired bonding process; and without removing the MNW from a template membrane that fills an interstitial volume of the MNW, depositing the bonding material onto a tip of the MNW.