Abstract: Thermal control systems that include variable conductivity metamaterial units are provided. The metamaterial unit a plurality of thermally conductive plates, a plurality of first bonds, each of which connects two adjoining thermally conductive plates, and a plurality of second bonds, each of which connects two adjoining thermally conductive plates. Also included is a load inducer constructed to cause the plurality of thermally conductive plates to move between a non-contact state, in which opposing surfaces of the plurality of thermally conductive plates are not in direct contact, to a contact state, in which the opposing surfaces of the plurality of thermally conductive are in at least partial direct contact, so as to change a thermal conductivity of the metamaterial unit from a first value to a second value.

Abstract: A heat pipe includes a a heat pipe wick having a gyroid or other periodic lattice structure, thereby providing relatively high porosity, high surface area, consistent pore size, structural stability, low tortuosity, and low convective acceleration.

Abstract: Thermal control systems that include variable conductivity metamaterial units are provided. The metamaterial unit a plurality of thermally conductive plates, a plurality of first bonds, each of which connects two adjoining thermally conductive plates, and a plurality of second bonds, each of which connects two adjoining thermally conductive plates. Also included is a load inducer constructed to cause the plurality of thermally conductive plates to move between a non-contact state, in which opposing surfaces of the plurality of thermally conductive plates are not in direct contact, to a contact state, in which the opposing surfaces of the plurality of thermally conductive are in at least partial direct contact, so as to change a thermal conductivity of the metamaterial unit from a first value to a second value.

Abstract: A thermally-controlled actuator includes a cylindrical anisogrid structure formed from a plurality of circumferentially offset clockwise and counter-clockwise helical members, and a plurality of longitudinally offset cylindrical ring members. A thermal control element is configured to control the temperature of at least some of the members. The cylindrical anisogrid structure has a top interface constraint and a bottom interface constraint, and the thermal control element is configured to control a displacement of the top interface constraint relative to the bottom interface constraint via control of the temperature of at least one of the helical members.

Abstract: A thermally-controlled actuator includes a cylindrical anisogrid structure formed from a plurality of circumferentially offset clockwise and counter-clockwise helical members, and a plurality of longitudinally offset cylindrical ring members. A thermal control element is configured to control the temperature of at least some of the members. The cylindrical anisogrid structure has a top interface constraint and a bottom interface constraint, and the thermal control element is configured to control a displacement of the top interface constraint relative to the bottom interface constraint via control of the temperature of at least one of the helical members.