Electroactive polymer releasable fastening system and method of use

• US 20040074069A1
• Filed: 02/05/2003
• Published: 04/22/2004
• Est. Priority Date: 10/19/2002
• Status: Active Grant

• Current Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Barvosa-Carter, William, Momoda, Leslie A., Johnson, Nancy L., Stanford, Thomas B., Browne, Alan Lampe
• Granted Patent: US 7,013,538 B2
• Time in Patent Office: Days
• US Class Current: 24/442
• CPC Class Codes: B64C 33/02 Wings; Actuating mechanisms therefor
• CPC Class Codes: C08L 2201/12 Shape memory
• CPC Class Codes: F16B 2200/77 Use of a shape-memory material
• CPC Class Codes: F16B 2200/81 Use of a material of the hooks-and-loops type
• CPC Class Codes: F16B 2200/83 Use of a magnetic material
• CPC Class Codes: F16B 5/07 by means of multiple interengaging protrusions on the surfaces, e.g. hooks, coils,
• CPC Class Codes: F16F 2224/045 magnetorheological
• CPC Class Codes: Y10S 24/44 Formations positioned along wall forming mating-member-guiding cavity
• CPC Class Codes: Y10T 24/27 including readily dissociable fastener having numerous, protruding, unitary filaments randomly interlocking with, and simultaneously moving towards, mating structure [e.g., hook-loop type fastener]
• CPC Class Codes: Y10T 24/45461 Interlocking portion actuated or released responsive to preselected condition [e.g., heat, pressure]
• CPC Class Codes: Y10T 24/45466 having electric or fluid powered, actuation or release, of interlock
• CPC Class Codes: Y10T 24/45471 Projection having movable connection between components thereof or variable configuration
• CPC Class Codes: Y10T 403/21 Utilizing thermal characteristic, e.g. , expansion or contraction, etc.

Abstract

A releasable fastening system for retaining two surfaces at each other or disengaging the two surfaces from each other comprises a first electrode disposed at a first surface, a second electrode disposed at a second surface, and a polymer film disposed between the first and second electrode, and an electrolyte disposed in electrical communication with the first electrode, the polymer film, and the second electrode. A volume of the polymer film is controllably variable to cause the retention of the first surface at the second surface. A method of releasably fastening adjacently-positioned surfaces comprises disposing a first electrode at a first surface, disposing a second electrode at a second surface, and increasing the volume of an electrolyte disposed in electrical communication with the first electrode and the second electrode to cause the retention of the first surface at the second surface.

Claims

1. A releasable fastening system, comprising:

a first electrode disposed at a first surface;

a second electrode disposed at a second surface;

a polymer disposed between said first and second electrodes, a volume of said polymer being controllably variable to cause the retention of said first surface at said second surface; and

an electrolyte disposed in electrical communication with said first electrode and said second electrode.

2. The releasable fastening system of claim 1, wherein the volume of said polymer is controllably variable in response to a voltage applied to said electrodes.

3. The releasable fastening system of claim 2, wherein said polymer is a film, said film being electro-activatable in response to said current applied to said electrodes.

4. An electro-activatable releasable fastening system, comprising:

a first electrode disposed at a first surface;

a second electrode disposed at a second surface;

an electrolyte disposed in electrical communication with said first electrode and said second electrode; and

a polymer film disposed between said first and second electrodes, said polymer film being electro-activatable in response to a voltage applied to said electrodes to effect the controlled engagement of said first surface and said second surface.

5. The electro-activatable releasable fastening system of claim 4, wherein said polymer film is conductive.

6. The electro-activatable releasable fastening system of claim 5, wherein said polymer film is polypyrrole.

7. The electro-activatable releasable fastening system of claim 4, wherein said electrolyte is an ionic liquid film.

8. The electro-activatable releasable fastening system of claim 4, wherein said first electrode comprises a post and said second electrode comprises a cavity configured to receive said post.

9. The electro-activatable releasable fastening system of claim 8, further comprising an alignment means disposed at said cavity to facilitate the receiving of said post at said cavity.

10. The electro-activatable releasable fastening system of claim 9, wherein said alignment means comprises a chamfered surface disposed at a mouth of said cavity.

11. The electro-activatable releasable fastening system of claim 8, wherein said post is retainable at said cavity via a mechanical means.

12. The electro-activatable releasable fastening system of claim 11, wherein said mechanical means comprises a fillet disposed at said cavity.

13. The electro-activatable releasable fastening system of claim 8, wherein said post comprises a knobbed member disposed at an end thereof, said knobbed member being engagable with an interlock surface disposed at said cavity.

14. A method of releasably fastening adjacently-positioned surfaces, said method comprising;

disposing a first electrode at a first surface;

disposing a second electrode at a second surface;

disposing a polymer film between said first and second electrodes;

disposing an electrolyte in electrical communication with said first and second electrode and said polymer film; and

increasing the volume of said polymer film to cause the retention of said first surface at said second surface.

15. The method of claim 14, wherein said increasing the volume of said electrolyte comprises directing a voltage through said first electrode, said electrolyte, and said second electrode to electrolytically activate said polymer film.

16. The method of claim 14, wherein said increasing the volume of said polymer film comprises mechanically biasing said polymer film.

17. The method of claim 16, wherein said mechanically biasing of said polymer film comprises,

directing a voltage to said second electrode to increase a volume of said polymer film,

extruding said electrolyte through said second electrode, and

engaging said extruded electrolyte at said second surface to cause the retention of said first surface at said second surface.

18. A releasable fastening system, comprising:

a first electrode disposed at a first surface;

a second electrode disposed at a first surface; and

a polymer disposed between said first and second electrodes, a configuration of said polymer being controllably variable to cause retention of said first surface at a second surface.

19. The releasable fastening system of claim 18, wherein said polymer has a volume dimension that is controllably variable in response to a voltage applied to said electrodes.

20. The releasable fastening system of claim 19, wherein said polymer is a film, said film being electro-activatable in response to said voltage applied to said electrodes.

21. An electro-activatable releasable fastening system, comprising:

a first electrode disposed at a first surface;

a second electrode disposed at a first surface; and

a polymer film disposed between said first and second electrodes, said polymer film being electro-activatable in response to a voltage applied to said electrodes to effect the controlled engagement of said first surface and a second surface.

22. The electro-activatable releasable fastening system of claim 21, wherein said polymer film is silicone dielectric.

23. The electro-activatable releasable fastening system of claim 21, wherein said first electrode and second electrode comprise a post and said second surface comprises a cavity configured to receive said post.

24. The electro-activatable releasable fastening system of claim 23, further comprising an alignment means disposed at said cavity to facilitate the receiving of said post at said cavity.

25. The electro-activatable releasable fastening system of claim 24, wherein said alignment means comprises a chamfered surface disposed at a mouth of said cavity.

26. The electro-activatable releasable fastening system of claim 23, wherein said post is retainable at said cavity via a mechanical means.

27. The electro-activatable releasable fastening system of claim 26, wherein said mechanical means comprises a fillet disposed at said cavity.

28. The electro-activatable releasable fastening system of claim 23, wherein said post comprises a knobbed member disposed at an end thereof, said knobbed member being engagable with an interlock surface disposed at said cavity.

29. A mechanically electro-activatable releasable fastening system, comprising:

a working electrode disposed at a first surface;

a non-compliant electrode disposed at said first surface, said non-compliant electrode having an opening defined therein; and

a polymer disposed in contact with said working electrode and said non-compliant electrode, said polymer being compressible such that said polymer is expandable through said opening in said non-compliant electrode to engage a second surface.

30. The mechanically electro-activatable releasable fastening system of claim 29, wherein said polymer is a dielectric polymer.

31. A method of releasably fastening adjacently-positioned surfaces, said method comprising;

disposing a first electrode at a first surface;

disposing a second electrode at a second surface;

disposing a polymer film between said first and second electrodes, and

changing the configuration of said polymer film to cause the retention of said first surface at said second surface.

32. The method of claim 31, wherein said changing the configuration of said polymer film comprises directing a voltage through said first electrode, said polymer film, and said second electrode to electrolytically activate said polymer film.

33. The method of claim 31, wherein said changing the configuration of said polymer film comprises mechanically biasing said polymer film.

34. The method of claim 33, wherein said mechanically biasing of said polymer film comprises,

directing a voltage to said second electrode to change the configuration of said polymer film,

extruding said polymer film through said second electrode, and

engaging said extruded polymer film at said second surface to cause the retention of said first surface at said second surface.