Abstract: A method of forming a three-dimensional (3D) composite structure includes: securing a mask between a collimated light source and a volume of a photo-monomer; directing a collimated light beam from the collimated light source to the mask for a period of exposure time such that a portion of the collimated light beam passes through the mask and is guided by a plurality of apertures into the photo-monomer to form a plurality of waveguides through a portion of the volume of the photo-monomer; removing any uncured photo-monomer to leave behind a three-dimensional ordered open-cellular microstructure to define an open volume and a structure of a first continuous material of the three-dimensional composite material; and placing a second continuous material in the open volume, wherein the second continuous material and the first continuous material share an interface between each other, and wherein the interface is everywhere continuous.

Abstract: Tunable variable emissivity materials, methods for fabricating tunable variable emissivity materials, and methods for controlling the temperature of a spacecraft using tunable variable emissivity materials have been provided. In an exemplary embodiment, a variable emissivity material has the formula M1(1?(x+y))M2xM3yMnO3, wherein M1 comprises lanthanum, praseodymium, scandium, yttrium, neodymium or samarium, M2 comprises an alkali earth metal, M3 comprises an alkali earth metal that is not M2, and x, y, and (x+y) are less than 1. The material has a critical temperature (Tc) in the range of about 270 to about 320K and a transition width is less than about 30K.

Abstract: An ordered ceramic microstructure and a method of making the same. In one embodiment, the ceramic microstructure includes a base structure and one or more ceramic layers. The base structure includes a plurality of first truss elements defined by a plurality of first self-propagating polymer waveguides and extending along a first direction, a plurality of second truss elements defined by a plurality of second self-propagating polymer waveguides and extending along a second direction, and a plurality of third truss elements defined by a plurality of third self-propagating polymer waveguides and extending along a third direction. Here, the first, second, and third truss elements interpenetrate each other at a plurality of nodes to form a continuous material, and the base structure is self-supporting. In addition, the ceramic layers coat a surface of at least one truss element of the first truss elements, the second truss elements, or the third truss elements.

Abstract: A three-dimensional (3D) composite structure and a method of making the same. In one embodiment, the 3D composite structure includes a 3D ordered microstructure and a second continuous material. The 3D ordered microstructure includes first truss elements defined by first self-propagating polymer waveguides and extending along a first direction, second truss elements defined by second self-propagating polymer waveguides and extending along a second direction, and third truss elements defined by third self-propagating polymer waveguides and extending along a third direction. The first, second, and third truss elements interpenetrate each other at nodes to form a first continuous material with the three-dimensional ordered microstructure. In addition, the second continuous material has different physical properties than the first continuous material and shares an interface with the three-dimensional ordered microstructure, and wherein the interface is everywhere continuous.

Abstract: A composite structure for storing thermal energy. In one embodiment, an apparatus for storing thermal energy includes: a thermal storage material and a three-dimensional structure. The three-dimensional structure includes: a plurality of first truss elements defined by a plurality of first self-propagating polymer waveguides and extending along a first direction; a plurality of second truss elements defined by a plurality of second self-propagating polymer waveguides and extending along a second direction; and a plurality of third truss elements defined by a plurality of third self-propagating polymer waveguides and extending along a third direction. The first, second, and third truss elements interpenetrate each other at a plurality of nodes to form a continuous material. The first, second, and third truss elements define an open space. The thermal storage material occupies at least a portion of the open space, and the three-dimensional structure is self-supporting.

Abstract: Tunable variable emissivity materials, methods for fabricating tunable variable emissivity materials, and methods for controlling the temperature of a spacecraft using tunable variable emissivity materials have been provided. In an exemplary embodiment, a variable emissivity material has the formula M1(1?(x+y))M2xM3yMnO3, wherein M1 comprises lanthanum, praseodymium, scandium, yttrium, neodymium or samarium, M2 comprises an alkali earth metal, M3 comprises an alkali earth metal that is not M2, and x, y, and (x+y) are less than 1. The material has a critical temperature (Tc) in the range of about 270 to about 320K and a transition width is less than about 30K.

Abstract: Flexible thermal control coatings for use on components of spacecraft and methods for fabricating such coatings are provided. In an exemplary embodiment, a flexible thermal control coating comprises a flexible organic binder for disposition on the component and an inorganic material having a radiation absorptance (?) of less than about 0.2 and an emissivity (?) of at least about 0.6. The inorganic material and the organic binder are oriented relative to each other so that an exterior surface of the coating has a higher concentration of inorganic material than an interior surface of the coating and a lower concentration of organic binder than the interior surface.

Abstract: Tunable variable emissivity materials, methods for fabricating tunable variable emissivity materials, and methods for controlling the temperature of a spacecraft using tunable variable emissivity materials have been provided. In an exemplary embodiment, a variable emissivity material has the formula M1(1?(x+y))M2xM3yMnO3, wherein M1 comprises lanthanum, praseodymium, scandium, yttrium, neodymium or samarium, M2 comprises an alkali earth metal, M3 comprises an alkali earth metal that is not M2, and x, y, and (x+y) are less than 1. The material has a critical temperature (Tc) in the range of about 270 to about 320K and a transition width is less than about 30K.

Abstract: An ordered ceramic microstructure and a method of making the same. In one embodiment, the ceramic microstructure includes a base structure and one or more ceramic layers. The base structure includes a plurality of first truss elements defined by a plurality of first self-propagating polymer waveguides and extending along a first direction, a plurality of second truss elements defined by a plurality of second self-propagating polymer waveguides and extending along a second direction, and a plurality of third truss elements defined by a plurality of third self-propagating polymer waveguides and extending along a third direction. Here, the first, second, and third truss elements interpenetrate each other at a plurality of nodes to form a continuous material, and the base structure is self-supporting. In addition, the ceramic layers coat a surface of at least one truss element of the first truss elements, the second truss elements, or the third truss elements.

Abstract: A composite structure for storing thermal energy. In one embodiment, an apparatus for storing thermal energy includes: a thermal storage material and a three-dimensional structure. The three-dimensional structure includes: a plurality of first truss elements defined by a plurality of first self-propagating polymer waveguides and extending along a first direction; a plurality of second truss elements defined by a plurality of second self-propagating polymer waveguides and extending along a second direction; and a plurality of third truss elements defined by a plurality of third self-propagating polymer waveguides and extending along a third direction. The first, second, and third truss elements interpenetrate each other at a plurality of nodes to form a continuous material. The first, second, and third truss elements define an open space. The thermal storage material occupies at least a portion of the open space, and the three-dimensional structure is self-supporting.

Abstract: Tunable variable emissivity materials, methods for fabricating tunable variable emissivity materials, and methods for controlling the temperature of a spacecraft using tunable variable emissivity materials have been provided. In an exemplary embodiment, a variable emissivity material has the formula M1(1?(x+y))M2xM3yMnO3, wherein M1 comprises lanthanum, praseodymium, scandium, yttrium, neodymium or samarium, M2 comprises an alkali earth metal, M3 comprises an alkali earth metal that is not M2, and x, y, and (x+y) are less than 1. The material has a critical temperature (Tc) in the range of about 270 to about 320 K and a transition width is less than about 30 K.

Abstract: Flexible thermal control coatings for use on components of spacecraft and methods for fabricating such coatings are provided. In an exemplary embodiment, a flexible thermal control coating comprises a flexible organic binder for disposition on the component and an inorganic material having a radiation absorptance (?) of less than about 0.2 and an emissivity (?) of at least about 0.6. The inorganic material and the organic binder are oriented relative to each other so that an exterior surface of the coating has a higher concentration of inorganic material than an interior surface of the coating and a lower concentration of organic binder than the interior surface.