A passive heat switch device is disclosed that includes a casing defining a closed channel, as well as a passive thermal actuator and liquid slug positioned inside the closed channel. The closed channel includes a heat conducting region made of a heat conducting material and an insulating region made of an insulating material. The passive thermal actuator is thermally coupled to the heat conducting material of the heat conducting region and extends into the insulating region of the closed channel. The passive thermal actuator deforms when an actuator temperature falls within a switching temperature range. The liquid slug is positioned within the closed channel and contacts at least a portion of the passive thermal actuator and the closed channel and is configured to move along the closed channel between the insulating region and the thermally conductive region in response to deformation of the passive thermal actuator.

A passive heat switch device is disclosed that includes a casing defining a closed channel, as well as a passive thermal actuator and liquid slug positioned inside the closed channel. The closed channel includes a heat conducting region made of a heat conducting material and an insulating region made of an insulating material. The passive thermal actuator is thermally coupled to the heat conducting material of the heat conducting region and extends into the insulating region of the closed channel. The passive thermal actuator deforms when an actuator temperature falls within a switching temperature range. The liquid slug is positioned within the closed channel and contacts at least a portion of the passive thermal actuator and the closed channel and is configured to move along the closed channel between the insulating region and the thermally conductive region in response to deformation of the passive thermal actuator.

An impingement cooling system includes a porous heat spreader and a nozzle configured to direct a fluid as a jet and/or as a spray impinging upon the porous heat spreader. The porous heat spreader is made of a thermally-conductive material such as a metal, metal alloy, carbon/graphite, or ceramic, and is in thermal contact with a heat source. The nozzle may be configured to direct the fluid as a jet comprising a single component liquid or gas (including air) or a liquid mixture such as water-glycol or other coolants. The nozzle may be configured to direct the fluid as a spray comprising a single component liquid or gas (including air) or a liquid mixture such as water-glycol or other coolants. The cooling system may include one or more nozzles, which may direct the cooling fluid orthogonally or at an oblique angle to an impingement plate.

A heat transfer device includes a first member and a first and second heat transfer element. In the first heat transfer element, a first contact area that is a contact area between the first heat transfer element and the first member varies. In the second heat transfer element, a second contact area that is a contact area between the second heat transfer element and the first member varies. The first contact area is greater when magnitude of a first external force applied to the first member is smaller than a first threshold than when the magnitude of the first external force is equal to or greater than the first threshold. The second contact area is smaller when the magnitude of the first external force is smaller than the first threshold than when the magnitude of the first external force is equal to or greater than the first threshold.

A heat transfer device includes a first member and a first and second heat transfer element. In the first heat transfer element, a first contact area that is a contact area between the first heat transfer element and the first member varies. In the second heat transfer element, a second contact area that is a contact area between the second heat transfer element and the first member varies. The first contact area is greater when magnitude of a first external force applied to the first member is smaller than a first threshold than when the magnitude of the first external force is equal to or greater than the first threshold. The second contact area is smaller when the magnitude of the first external force is smaller than the first threshold than when the magnitude of the first external force is equal to or greater than the first threshold.

Heat transfer devices, components thereof, and related methods are provided. Embodiments include heat transfer devices and/or heat transfer components including a spinodal structure having a bi-continuous topology obtained by modeling a spinodal decomposition process, wherein the spinodal structure having the bi-continuous topology is a spinodal shell structure or a spinodal solid structure. Embodiments include methods of making heat transfer devices and/or heat transfer components using additive manufacturing. Other further embodiments are provided in the present disclosure.

A diode lighting module comprising both a diode matrix mounted on a support plate and heat dissipator means for dissipating the heat given off by the diode matrix, includes a metal plate having an outside face in contact with the support plate and an inside face supporting a cellular metal foam including a plurality of calibrated holes passing through each cell in two perpendicular directions, and a vessel-forming box filled with the cellular metal foam and for which the metal plate constitutes a lid. The box has inlet and outlet orifices passing through the box to receive a cooling liquid, and a separator defining two separate cooling fluid flow zones in the cellular metal foam, a cooling fluid feed zone and a cooling fluid discharge zone, with passage from one of the zones to the other taking place through a cutout in the separator.

A cooling system for electrical and optical devices includes an electrocaloric cooler (EEC). A fluid circuit is in thermal communication with the EEC to dump heat from a working fluid of the fluid circuit into the EEC. The system can include a second EEC, a second fluid circuit in thermal communication with the second EEC to dump heat from a working fluid of the second fluid circuit into the EEC, and a second heat sink in thermal communication with the second fluid circuit to dump heat into the working fluid of the second fluid circuit. The second EEC, second fluid circuit, and second heat sink can be cascaded with the first EEC, first heat sink, and first fluid circuit wherein the second heat sink is in thermal communication with the first EEC to accept heat therefrom.

A heat exchanger incorporates a metal hydride heat exchanger and mitigates the fluid mixing process, and thus greatly improves the heat transfer efficiency and heat recovery processes. The metal hydride heat exchanger has a container for the metal hydride that has a large aspect ratio. A plurality of high aspect container for the metal hydride may be coupled with a manifold.

Tamper-respondent assemblies are provided which include a circuit board, an enclosure assembly mounted to the circuit board, and a pressure sensor. The circuit board includes an electronic component, and the enclosure assembly is mounted to the circuit board to enclose the electronic component within a secure volume. The enclosure assembly includes a thermally conductive enclosure with a sealed inner compartment, and a porous heat transfer element within the sealed inner compartment. The porous heat transfer element is sized and located to facilitate conducting heat from the electronic component across the sealed inner compartment of the thermally conductive enclosure. The pressure sensor senses pressure within the sealed inner compartment of the thermally conductive enclosure to facilitate identifying a pressure change indicative of a tamper event.