Patent Number: 
Section: claims

1. A method of increasing the thermal emissivity of a surface of an object comprising the step of: forming a cavity structure on the surface defining a plurality of cavities, said cavity structure further defining a plurality of cavity apertures and cavity surfaces, wherein said cavity structure has an average cavity area aspect ratio of at least 8. 2. The method of  claim 1 , wherein said forming comprises selectively removing material from the surface of the object. claim 1 3. The method of  claim 1 , wherein said forming comprises selectively adding material to the surface of the object. claim 1 4. The method of  claim 1 , wherein the ratio of the cumulative cross-sectional area of said plurality of cavity apertures to surface area that is not occupied by said plurality of cavity apertures is greater than about 1:4. claim 1 5. The method of  claim 4 , wherein the ratio of the cumulative cross-sectional area of said plurality of cavity apertures to surface area that is not occupied by said plurality of cavity apertures is greater than about 2:1. claim 4 6. The method of  claim 1 , wherein said plurality of cavity apertures form a geometric array on the surface of the object. claim 1 7. The method of  claim 1 , wherein said plurality of cavity apertures are circular in shape. claim 1 8. The method of  claim 7 , wherein said plurality of cavity apertures have approximately the same diameter. claim 7 9. The method of  claim 1 , wherein the average effective diameter of said plurality of cavity apertures is at least 10 xcexcm. claim 1 10. The method of  claim 1 , further comprising the step of backfilling at least a portion of said plurality of cavities in said cavity structure with a material that is substantially transparent to incident and emitted radiation. claim 1 11. A method of controlling the amount of radiation transferred between a surface of an object and its environment in situ, comprising the steps of: forming a cavity structure on the surface defining a plurality of cavities, said cavity structure further defining a plurality of cavity apertures and cavity surfaces, wherein said cavity structure has an average cavity area aspect ratio of at least 8; and  changing the degree of blackbody behavior of the surface by changing a physical characteristic of said cavity structure in situ. 12. The method of  claim 11 , wherein said physical characteristic is selected from the group consisting of cavity area aspect ratio, cavity longitudinal axis orientation, and combinations thereof. claim 11 13. The method of  claim 12 , wherein changing the cavity area aspect ratio is by changing the area of at least a portion of said plurality of cavity apertures. claim 12 14. The method of  claim 13 , wherein changing the area of at least a portion of said plurality of cavity apertures is by moving at least one cap proximate said portion of cavity apertures. claim 13 15. The method of  claim 14 , wherein said at least one cap incorporates an activate element selected from the group consisting of bimetallic, shape memory, piezoelectric, magnetic, magnetostrictive, and combinations thereof. claim 14 16. The method of  claim 13 , wherein changing the area of at least a portion of said plurality of cavity apertures is by deforming said portion of cavity apertures. claim 13 17. The method of  claim 12 , wherein changing the cavity area aspect ratio is by changing the area of at least a portion of said plurality of cavity surfaces. claim 12 18. The method of  claim 17 , wherein changing the area of at least a portion of said plurality of cavity surfaces is by changing the level of a selector contained in said portion of said plurality of cavities. claim 17 19. The method of  claim 11 , further comprising the step of backfilling at least a portion of said plurality of cavities in said cavity structure with a selector, wherein said selector is selected from the group consisting of luminescent materials, liquid crystals, photochromes, electrochromes, and combinations thereof. claim 11 20. The method of  claim 11 , wherein changing said physical characteristic is caused by a stimulus selected from the group consisting of temperature, chemistry, biology, humidity, pressure, electrical current, electric field, voltage, magnetic field, electromagnetic radiation, particle radiation, mechanical force, and combinations thereof. claim 11 21. The method of  claim 11 , wherein the average effective diameter of said plurality of cavity apertures is at least 10 xcexcm. claim 11 22. A surface structure that increases the thermal emissivity of a surface of an object, comprising: a cavity structure defining a plurality of cavities, said cavity structure further defining a plurality of cavity apertures and cavity surfaces, wherein said cavity structure has an average cavity area aspect ratio of at least 8. 23. The surface structure of  claim 22 , wherein the ratio of the cumulative cross-sectional area of said plurality of cavity apertures to surface area that is not occupied by said plurality of cavity apertures is greater than about 1:4. claim 22 24. The surface structure of  claim 23 , wherein the ratio of the cumulative cross-sectional area of said plurality of cavity apertures to surface area that is not occupied by said plurality of cavity apertures is greater than about 2:1. claim 23 25. The surface structure of  claim 22 , wherein said plurality of cavity apertures form a geometric array on the surface. claim 22 26. The surface structure of  claim 22 , wherein said plurality of cavity apertures are circular in shape. claim 22 27. The surface structure of  claim 26 , wherein said plurality of cavity apertures have approximately the same diameter. claim 26 28. The surface structure of  claim 22 , wherein the average effective diameter of said plurality of cavity apertures is at least 10 xcexcm. claim 22 29. The surface structure of  claim 22 , further comprising a material that backfills at least a portion of said plurality of cavities in said cavity structure, said material substantially transparent to incident and emitted radiation. claim 22 30. A controllable surface structure for controlling the amount of radiation transferred between a surface of an object and its environment in situ, comprising: a cavity structure defining a plurality of cavities, said cavity structure further defining a plurality of cavity apertures and cavity surfaces, wherein said cavity structure has an average cavity area aspect ratio of at least 8; and  a means to change a physical characteristic of said cavity structure in situ to control the degree of blackbody behavior of the surface. 31. The controllable surface structure of  claim 30 , wherein said physical characteristic is selected from the group consisting of cavity area aspect ratio, cavity longitudinal axis orientation, and combinations thereof. claim 30 32. The controllable surface structure of  claim 30 , wherein said means is selected from the group consisting of electrical, mechanical, and combinations thereof. claim 30 33. The controllable surface structure of  claim 30 , wherein the average effective diameter of said plurality of cavity apertures is at least 10 xcexcm. claim 30 34. The controllable surface structure of  claim 30 , further comprising a selector in at least a portion of said plurality of cavities. claim 30 35. The controllable surface structure of  claim 34 , wherein said selector is selected from the group consisting of luminescent materials, liquid crystals, photochromes, electrochromes, and combinations thereof. claim 34