초록 ▼

Reconfigurable radiant energy reflectors ( 3 ) of very low areal densities are formed of a laminate of a thin layer of a shape memory alloy ( 17 ) and a thin film or membrane material ( 15 ). The outer surface of the membrane provides the energy reflecting surface ( 16 ) and a support member ( 11 )

Reconfigurable radiant energy reflectors ( 3 ) of very low areal densities are formed of a laminate of a thin layer of a shape memory alloy ( 17 ) and a thin film or membrane material ( 15 ). The outer surface of the membrane provides the energy reflecting surface ( 16 ) and a support member ( 11 ) is attached to the laminate for application in a system. In a preferred embodiment, the shape memory alloy ( 17 ) is compositionally graded ( 18, 19, 29, 21 ) and exhibits a two-way shape memory effect and a heater ( 5 ) serves as the actuator to the reflector.

대표청구항 ▼

1. The method of redirecting radiant energy originating from a remote source comprising the steps of:placing a shape memory alloy containing a radiant energy reflective surface of a first configuration in a position to receive incident radiant energy from said remote source; andchanging the shape of

1. The method of redirecting radiant energy originating from a remote source comprising the steps of:placing a shape memory alloy containing a radiant energy reflective surface of a first configuration in a position to receive incident radiant energy from said remote source; andchanging the shape of said radiant energy reflective surface to a second configuration to reflect incident radiant energy in a direction different from said first configuration. 2. The method of redirecting radiant energy as defined in claim 1, wherein said step of changing the shape of said radiant energy reflective surface to a second configuration comprises the step of applying energy to said shape memory alloy. 3. The method of redirecting radiant energy as defined in claim 2, wherein said step of applying energy to said shape memory alloy further comprises applying heat energy to said shape memory alloy. 4. The method of redirecting radiant energy as defined in claim 3, wherein said step of applying heat energy to said shape memory alloy includes: pointing a laser at said shape memory alloy and directing a laser beam output from said laser onto said shape memory alloy. 5. The method of redirecting radiant energy as defined in claim 4, wherein directing a laser beam output from said laser onto said shape memory alloy includes scanning said laser beam over a surface of said shape memory alloy. 6. The method of redirecting radiant energy as defined in claim 4, wherein directing a laser beam output from said laser onto said shape memory alloy includes the step of directing said laser beam over a predetermined portion of said surface of said shape memory alloy. 7. The method of redirecting radiant energy as defined in claim 3, wherein said step of applying heat energy to said shape memory alloy includes: applying a heating current to a heater coupled to said shape memory alloy. 8. A reconfigurable reflector for space vehicle application, comprising:a thin layer of film material, said layer of film material containing front and rear surfaces and being of a predetermined surface geometry;said front surface of said thin layer containing a reflective surface for reflecting radiant energy;a thin layer of a shape memory alloy sputtered onto and covering said rear surface of said layer of film material and defining therewith a unitary one-piece laminate film structure having said geometry of said thin layer of limp film material;said shape memory alloy having a predetermined transformation temperaturesaid unitary one-piece laminate film structure being manually deformable into a second shape different from said predetermined geometry, wherein said unitary one-piece laminate film structure is retained in said second shape following manual deformation so long as the temperature of said unitary one-piece laminate film structure remains below said predetermined transformation temperature; andsaid unitary one-piece laminate film structure being capable of restoring to said predetermined geometry from said second shape when said temperature of said unitary one-piece laminate film structure is raised to said transformation temperature. 9. The reflector for space vehicle application as defined in claim 8, wherein said shape memory alloy comprises a nickel titanium alloy. 10. The reflector for space vehicle application as defined in claim 8, wherein said film material comprises CP-1. 11. The reflector for space vehicle application as defined in claim 8, wherein said film material comprises a polymer. 12. The reflector for space vehicle application as defined in claim 8, wherein said layer of shape memory alloy comprises a compositionally graded layer of a two component metal alloy in which the percentage of a first component metal in said alloy increases as a function of the height of said layer of shape memory allow. 13. The reflector for space vehicle application as defined in claim 12, wherein said shape memory alloy comprises a nickel titanium alloy, and where sai d percentage of said titanium in said alloy is 51 percent at the bottom side of said layer of shape memory alloy and said percentage is 49 percent at the upper side of said layer of shape memory alloy. 14. The reflector for space vehicle application as defined in claim 12, further comprising: an electric heater in heat energy coupling relationship with said laminate film structure; and switching means for generating heat, said switching means having a closed position for applying electric current to said electric heater, wherein said electric heater generates sufficient heat to raise the temperature of said laminate film structure above said transformation temperature, and an open state for interrupting electric current to said electric heater and discontinue generation of heat, wherein the temperature of said reflector falls below said transformation temperature. 15. The reflector for space vehicle application as defined in claim 14, further comprising: a receiver of radiant energy, said receiver including an input, said input of said receiver being focused on said reflector for receiving radiant energy reflected from said reflector. 16. The reflector for space vehicle application as defined in claim 15, wherein said shape memory alloy comprises a nickel titanium alloy, and where said percentage of said titanium in said alloy is 51 per cent at the bottom side of said layer of shape memory alloy and said percentage is 49 per cent at the upper side of said layer of shape memory alloy. 17. The reflector for space vehicle application as defined in claim 8, further comprising: an electric heater in heat energy coupling relationship with said laminate film structure; and switching means for generating heat, said switching means having a closed position for applying electric current to said electric heater, wherein said electric heater generates sufficient heat to raise the temperature of said laminate film structure above said transformation temperature, and an open state for interrupting electric current to said electric heater and discontinue generation of heat, wherein the temperature of said reflector falls below said transformation temperature. 18. The reflector for space vehicle application as defined in claim 17, further comprising: a receiver of radiant energy, said receiver including an input, said input of said receiver being focused on said reflector for receiving radiant energy reflected from said reflector. 19. The reflector for space vehicle application as defined in claim 8, further comprising: a mounting member for said laminate, said mounting member being attached to said laminate film structure for supporting said laminate film structure to a space vehicle. 20. A method of producing a reflector comprising the steps of:draping a reflective membrane onto a support surface inside a sputtering chamber, said support surface defining the geometry of a reflector and the reflective surface of said reflective membrane being oriented face down against said support surface; andsputtering a shape memory alloy onto the outer surface of said reflective membrane to cover said surface and produce a laminate assembly of reflective membrane and shape memory alloy, said outer surface of said reflective membrane being opposite to said reflective surface. 21. The method of producing a reflector as defined in claim 20, further comprising the step, following the step of draping said reflective surface onto said support surface, of said heating shape memory alloy for sputtering and maintaining said heating during said step of sputtering. 22. The method of producing a reflector as defined in claim 20, further comprising the steps, following the step of draping said reflective surface onto said support surface, of raising the temperature of the shape memory alloy used for sputtering to a predetermined initial temperature at the commencement of said step of sputtering, and gradually raising said temperature in steps at various time interval s during said step of sputtering. 23. The method of producing a reflector as defined in claim 22, further comprising the step of cooling said laminate assembly, following the step of sputtering; and further comprising the step of manually deforming said laminate assembly into a compact shape, said compact shape being different than said shape of said reflector. 24. The method of forming a graded composition of a two metal alloy on a membrane, comprisingheating the source of sputtering metals to a first temperature;sputtering two metals upon said membrane to deposit a metal alloy of the two metals on said membrane;increasing the heating of said source of sputtering metals incrementally to incrementally raise the temperature of said source while continuing said sputtering of said two metals to incrementally change the composition of said metal alloy being deposited, each said increment being maintained for a prescribed interval. 25. A method of making a reflector comprising the steps of:joining together a reflective film and layer of compositionally graded shape memory alloy into a unitary integral structure of a given geometry; andattaching a reflector support member to said unitary integral structure. 26. The method of making a reflector as defined in claim 25, further comprising:manually changing the geometry said unitary integral structure from said given geometry to a different geometry.