A heat rejection system that employs temperature sensitive shape memory materials to control the heat rejection capacity of a vehicle to maintain a safe vehicle temperature. The technology provides for a wide range of heat rejection rates by actuation of the orientation or position of a heat rejection panel which impacts effective properties of the heat rejection system in response to temperature. When employed as a radiator for crewed spacecraft thermal control this permits the use of higher freezing point, non-toxic thermal working fluids in single-loop thermal control systems for crewed vehicles in space and other extraterrestrial environments.

There is provided a heat-conductive flexible sheet that is formed of a non-silicone material and excellent in flexibility as well as durability such as heat-aging resistance, hydrothermal resistance, and thermal shock resistance, and a heat dissipation structure using the same, as well as a resin composition that exhibits excellent handleability in the kneading step in producing a heat-conductive sheet and can be suitably used as a binder material for a heat-conductive flexible sheet. A resin composition comprising a blocked urethane prepolymer, a predetermined epoxy compound, and a curing catalyst, the blocked urethane prepolymer being a reaction product of an aliphatic diisocyanate compound and a hydrogenated polybutadiene polyol having a hydroxy group at each of both ends, wherein the reaction product has at an end thereof an isocyanate group blocked with an aromatic hydroxy compound; a heat-conductive flexible sheet formed of a cured product of a mixed composition comprising the same and a heat-conductive inorganic filler; and a heat dissipation structure using the same.

An apparatus includes a heat sink configured to receive thermal energy from one or more heat sources. The heat sink includes a local reservoir configured to hold a liquid coolant, and the heat sink is configured to pass the thermal energy into the liquid coolant in the local reservoir in order to vaporize at least some of the liquid coolant. The apparatus also includes a membrane configured to allow vaporized coolant to pass through the membrane out of the local reservoir into an ambient environment and to prevent unvaporized coolant from passing through the membrane. The membrane is thereby configured to provide passive flow control for the liquid coolant. The membrane could include a vapor-permeable and liquid-repelling membrane. The membrane can also be configured to hold the liquid coolant in the local reservoir against one or more surfaces of the heat sink.

An apparatus includes a heat sink configured to receive thermal energy from one or more heat sources. The heat sink includes a local reservoir configured to hold a liquid coolant, and the heat sink is configured to pass the thermal energy into the liquid coolant in the local reservoir in order to vaporize at least some of the liquid coolant. The apparatus also includes a membrane configured to allow vaporized coolant to pass through the membrane out of the local reservoir into an ambient environment and to prevent unvaporized coolant from passing through the membrane. The membrane is thereby configured to provide passive flow control for the liquid coolant. The membrane could include a vapor-permeable and liquid-repelling membrane. The membrane can also be configured to hold the liquid coolant in the local reservoir against one or more surfaces of the heat sink.

An apparatus includes a thermally conductive interface assembly including a first component associated with a first interface surface and a second component associated with a second interface surface. The apparatus also includes a shape memory alloy component coupled to the thermally conductive interface assembly and configured to move one or more components of the thermally conductive interface assembly between a first state and a second state based on a temperature of the shape memory alloy component. In the first state, the first interface surface is in physical contact with the second interface surface, and in the second state, a gap is defined between the first interface surface and the second interface surface.

An apparatus includes a thermally conductive interface assembly including a first component associated with a first interface surface and a second component associated with a second interface surface. The apparatus also includes a shape memory alloy component coupled to the thermally conductive interface assembly and configured to move one or more components of the thermally conductive interface assembly between a first state and a second state based on a temperature of the shape memory alloy component. In the first state, the first interface surface is in physical contact with the second interface surface, and in the second state, a gap is defined between the first interface surface and the second interface surface.

A heat dissipation device may be formed having at least one isotropic thermally conductive section (uniformly high thermal conductivity in all directions) and at least one anisotropic thermally conductive section (high thermal conductivity in at least one direction and low thermal conductivity in at least one other direction). The heat dissipation device may be thermally coupled to a plurality of integrated circuit devices such that at least a portion of the isotropic thermally conductive section(s) and/or the anisotropic thermally conductive section(s) is positioned over at least one integrated circuit device. The isotropic thermally conductive section(s) allows heat spreading/removal from hotspots or areas with high-power density and the anisotropic thermally conductive section(s) transfers heat away from the at least one integrated circuit device predominately in a single direction with minimum conduction resistance in areas with uniform power density distribution, while reducing heat transfer in the other directions, thereby reducing thermal cross-talk.

Provided are heat transfer components that include a wick and a working fluid enclosed within a sealed evacuated space. Also provided are related methods of using the components.

A thermal switch having an on-state and an off-state is provided. First and second plates are composed from a thermally conductive material. The first and second plates are connected to form an internal cavity having a channel defining a gap between the first and second plate. The first reservoir is coupled to the channel and contains a thermally conductive liquid. The actuator is coupled to the first reservoir and the channel and is moveable between a first state and a second state corresponding to the on-state and the off-state of the thermal switch, respectively. Thermally conductive liquid is allowed to flow from the first reservoir to the channel when the actuator is in the first state and allowed to flow from the channel to the first reservoir when the actuator is in the second state.

A thermal switch having an on-state and an off-state is provided. First and second plates are composed from a thermally conductive material. The first and second plates are connected to form an internal cavity having a channel defining a gap between the first and second plate. The first reservoir is coupled to the channel and contains a thermally conductive liquid. The actuator is coupled to the first reservoir and the channel and is moveable between a first state and a second state corresponding to the on-state and the off-state of the thermal switch, respectively. Thermally conductive liquid is allowed to flow from the first reservoir to the channel when the actuator is in the first state and allowed to flow from the channel to the first reservoir when the actuator is in the second state.