A method for fabricating a super-hydrophobic surface having excellent surface strength and an evaporator having the super-hydrophobic surface fabricated by the method are provided. The method includes preparing a metal base material, anodizing the metal base material to form a ceramic layer having a complex structure of a microstructure and nano-fiber structures on a surface of the metal base material, and applying a hydrophobic polymer material on the complex structure to form a polymer layer having the same surface shape as the complex structure.

Omniphilic and superomniphilic surfaces for simultaneous vapor condensation and airborne liquid droplet collection are provided. Also provided are methods for using the surfaces to condense liquid vapor and/or capture airborne liquid droplets, such as water droplets found in mist and fog. The surfaces provide enhanced capture and transport efficiency based on preferential capillary condensation on high surface energy surfaces, thin film dynamics, and force convection.

A heat transfer device for transferring heat energy to or from a gas or fluid flowing radially across a plurality of posts or tubes includes a plate having a plate surface. A plurality of posts or tubes are disposed on and protrude substantially perpendicular to the plate surface. At least about 50% of the plurality of posts or tubes are disposed according to a phyllotaxis layout. Each arc of a plurality of phyllotaxis spiral arcs of the phyllotaxis layout terminates at different locations along an arc radius on the plate at a phyllotaxis arc termination radius less than a perimeter radius.

A composite material for passive radiative cooling including a base layer, and at least one emissive layer located adjacent to a surface of the base layer, wherein the at least one emissive layer is affixed to the surface of the base layer via a binding agent. Also disclosed are methods of applying passive coolers to articles and surfaces to be adapted for passive radiative cooling.

Embodiments described herein generally relate to a multi-mode heat transfer system. The heat transfer system includes an emitter device. The emitter device includes an inner core surrounded by an outer core having a thickness and an outer surface. A composite material pattern extends through at least a portion of the outer surface and at least a portion of the thickness of the outer core and is thermally coupled to the inner core. The composite material pattern in combination with an optimized emissivity surface coating/paint profile directs a heat from the inner core to an object other than the emitter device.

Embodiments described herein generally relate to a multi-mode heat transfer system. The heat transfer system includes an emitter device. The emitter device includes an inner core surrounded by an outer core having a thickness and an outer surface. A composite material pattern extends through at least a portion of the outer surface and at least a portion of the thickness of the outer core and is thermally coupled to the inner core. The composite material pattern in combination with an optimized emissivity surface coating/paint profile directs a heat from the inner core to an object other than the emitter device.

Sub-micrometer to centimeter scale rough symmetric and asymmetric structures are incorporated onto objects (e.g. tubes and fms). Asymmetric and hierarchically structured slippery structures can be applied to a broad range of materials and shapes of surfaces for manufacturing heat exchangers, dew harvesting devices, desalination devices, de-humidifiers, distillation towers, evaporation coils, anti-cavitation coatings, etc.

Flow paths and boundary layer restart features are provided. For example, a flow path comprises a flow path wall defining an inner flow path surface and an asymmetric notch defined in the flow path wall. The asymmetric notch comprises a first surface and a second surface and is asymmetric about a first line extending through an intersection of the first and second surfaces. Further, a flow boundary layer restart feature comprises a first surface extending inward with respect to a flow path surface of a flow path and a second surface extending inward with respect to the flow path surface. The second surface is asymmetric with respect to the first surface such that the first and second surfaces define an asymmetric notch. Additionally, a flow path wall may comprise an asymmetric notch that includes a flow expansion angle and a flow contraction angle that are unequal.

Systems and methods for radiative cooling and heating are provided. For example, systems for radiative cooling can include a top layer including one or more polymers, where the top layer has high emissivity in at least a portion of the thermal spectrum and an electromagnetic extinction coefficient of approximately zero, absorptivity of approximately zero, and high transmittance in at least a portion of the solar spectrum, and further include a reflective layer including one or more metals, where the reflective layer has high reflectivity in at least a portion of the solar spectrum.

According to the present specification there is provided a rotatable heat sink device which comprises a heat sink configured to enclose a cooling fluid, and the heat sink is rotatable about a rotational axis. The heat sink, in turn, comprises a first portion configured to receive thermal energy from a source external to the heat sink, and a second portion configured to dissipate at least a portion of the thermal energy to surroundings external to the device. The device further comprises an optical wavelength conversion material disposed on an outside surface of the first portion of the heat sink, and an agitator disposed inside the heat sink. The agitator is rotationally independent of the heat sink and is configured to promote circulation of the cooling fluid between the first portion and the second portion.