Electromechanical actuator and methods of providing same

• US 20050006989A1
• Filed: 11/25/2002
• Published: 01/13/2005
• Est. Priority Date: 11/23/2001
• Status: Active Grant

• Current Assignee: Dezhi Zhou, Geoffrey M. Spinks, Gordon George Wallace
• Original Assignee: Dezhi Zhou, Geoffrey M. Spinks, Gordon George Wallace
• Inventors: Wallace, Gordon George, Zhou, Dezhi, Spinks, Geoffrey M.
• Granted Patent: US 7,242,134 B2
• Time in Patent Office: Days
• US Class Current: 62/440
• CPC Class Codes: A61F 2/08 Muscles; Tendons; Ligaments sutures A61B17/04
• CPC Class Codes: A61F 2002/0894 Muscles non-implantable A61F2002/5066
• CPC Class Codes: C08G 61/123 derived from five-membered heterocyclic compounds
• CPC Class Codes: F03G 7/06 using expansion or contraction of bodies due to heating, cooling, moistening, drying or the like using thermal expansion of non-vaporising liquids F01K
• CPC Class Codes: H01B 1/122 Ionic conductors
• CPC Class Codes: H01B 1/127 comprising five-membered aromatic rings in the main chain, e.g. polypyrroles, polythiophenes
• CPC Class Codes: Y10S 310/80 Piezoelectric polymers, e.g. PVDF

Abstract

An electromechanical actuator comprising an inherently conducting polymer and a conductor for conducing voltage along the polymer from a first end region thereof. The conductor is adapted for axially extending and contracting with axial expansion and contraction of the polymer. In one form, the conductor is in the form of a helix embedded in the polymer and extends along substantially the entire length of the polymer. Also disclosed is a method for manufacture of the electromechanical actuator.

Claims

1. An electromechanical actuator for effecting a desired action, comprising:

a conducting polymer and a conductor for conducting voltage along the polymer from one end region of the polymer to an opposite end region of the polymer;

wherein the conductor is adapted for extending and retracting with expansion and contraction of the polymer, and extends along the polymer from the one end region to the opposite end region.

2. An electromechanical actuator according to claim 1 wherein the conductor is in intimate electrical contact along the polymer from the one end region of the polymer to the opposite end region.

3. An electromechanical actuator according to claim 1 wherein the conductor is embedded in the polymer

4. An electromechanical actuator according to claim 1 wherein the conductor is wound in a helix along the polymer for conducting the voltage along the polymer from one end region of the polymer to the opposite end region.

5. An electromechanical actuator according to claim 1 wherein the conductor is arranged in a concertina pattern along the polymer for extension and retraction with the polymer.

6. An electromechanical actuator according to claim 1 and further comprising a template received by the polymer and wherein the polymer is slidable along the template with expansion and contraction of the polymer.

7. An electromechanical actuator according to claim 6 wherein one end region of the conductor is in electrical contact with one end region of the template and an opposite end region of the conductor is in electrical contact with a corresponding end region of the template.

8. An electromechanical actuator according to claim 6 wherein the template comprises a further conductor.

9. An electromechanical actuator according to claim 8 wherein the conducting polymer is in the form of a tube.

10. An electromechanical actuator according to claim 8 and further comprising an electrical connector for facilitating connection of the conductor to an electrical circuit and being connected to one end region of the conductor.

11. An electromechanical actuator according to claim 10 and further comprising an electrical connector for facilitating connection of the conductor to the electrical circuit and being connected to an opposite end region of the conductor.

12. An electromechanical actuator according to claim 11 wherein the polymer is selected from the group consisting of polyaniline, polypyrrole, polythiophene, derivatives thereof, and mixtures of the foregoing.

13. An electromechanical actuator according to claim 12 wherein the derivatives are selected from the group consisting of alkyl, alkoxy, amine and alcohol derivatives.

14. An electromechanical actuator according to claim 1 and further comprising an ionic liquid electrolyte.

15. An electromechanical actuator according to claim 14 wherein the ionic liquid is selected from 1-ethyl-3-methyl imidazolium bis(trifluoromethanesulfonyl) amide and 1-butyl-3-methylimidazolium hexafluorophosphate.

16. An electromechanical actuator according to claim 15 wherein the conductor is a metal conductor.

17. An electromechanical actuator according to claim 1 wherein the conductor is a wire.

18. An electromechanical actuator for effecting a desired action, comprising:

an outer actuator comprising a tubular conducting polymer having a hollow interior;

an inner actuator comprising a further conducting polymer; and

an electrolyte in a space defined between the inner actuator and the outer actuator;

wherein the inner actuator is arranged within the outer actuator and lies along the hollow interior of the outer actuator for axial expansion and contraction within the outer actuator.

19. An electromechanical actuator according to claim 18 wherein the inner actuator is arranged within the outer actuator for axial expansion and contraction of the further polymer with axial expansion or contraction of the tubular conducting polymer.

20. An electromechanical actuator according to claim 18 wherein the inner actuator is arranged within the outer actuator for axial expansion and contraction in opposition to axial expansion and contraction of tubular conducting polymer.

21. An electromechanical actuator according to claim 18 wherein at least one of the inner actuator and the outer actuator further comprises a conductor for conducting voltage along either the further polymer or the tubular conducting polymer of the actuator to which the conductor corresponds from one end region thereof to an opposite end region thereof, and wherein the conductor is adapted for axially extending and retracting.

22. An electromechanical actuator according to claim 21 wherein the inner actuator incorporates a said conductor for conducting voltage along the further polymer from one end region of the further polymer to an opposite end region of the further polymer, and wherein the conductor is adapted for axially extending and retracting with the axial expansion and contraction of the further polymer.

23. An electromechanical actuator according to claim 22 wherein the conductor is in intimate electrical contact along the further polymer from the one end region to the opposite end region.

24. An electromechanical actuator according to claim 22 wherein the conductor is embedded in the further polymer.

25. An electromechanical actuator according to claim 22 wherein the conductor is wound in a helix along the further polymer for conducting the voltage along the further polymer form the one end region of the polymer to the opposite end region.

26. An electromechanical actuator according to claim 18 wherein the further conducting polymer is in tubular form.

27. An electromechanical actuator according to claim 18 wherein the tubular conducting polymer and the further conducting polymer are the same or different.

28. An electromechanical actuator according to claim 27 wherein the further conducting polymer is selected from the group consisting of polyaniline, polypyrrole, polythiophene, derivatives thereof, and mixtures of the foregoing.

29. An electromechanical actuator according to claim 18 wherein the electrolyte is an ionic liquid electrolyte.

30. An electromechanical actuator according to claim 29 wherein the ionic liquid electrolyte comprises an ionic liquid selected from the group consisting of 1-ethyl-3-methyl imidazolium bis(trisfluoromethanesulfonyl) amide and 1-butyl-3-methylimidazolium hexafluorophosphate.

31. An electromechanical actuator according to arranging a conductor for conducting voltage along a conducting polymer from on end region of the polymer to an opposite end region of the polymer and so that the conductor extends along the polymer from the one end region to the opposite end region for axially extending and contracting with expansion and contraction of the polymer.

32. A method according to claim 31 further comprising embedding the conductor in the polymer.

33. A method according to claim 31 wherein the arranging of the conductor comprises winding the conductor around a template to form a helix along the template.

34. A method according to claim 33 wherein the helix has a pithc of about 10 turns cm⁻

1 or greater.

35. A method according to claim 33 further comprising coating the conductor and the template with the polymer such that the conductor is embedded in the polymer.

36. A method according to claim 35 wherein the coating comprises electrodepositing the polymer into the conductor and the template.

37. A method according to claim 32 wherein embedding the conductor in the polymer comprises coating the conductor with the polymer by electrodepositing the polymer onto the conductor.

38. A method according to claim 33 further comprising removing the template leaving a tube of the polymer in which the conductor is embedded.

39. A method according to claim 31 further comprising connecting an electrical connector to one end of the conductor for facilitating connection of the conductor to an electrical circuit.

40. A method according to claim 39 further comprising connecting another electrical connector to an opposite end of the conductor.

41. A method according to claim 39 comprising winding the conductor about said another electrical conductor to thereby connect the conductor to said another electrical connector.

42. A method according to claim 39 further comprising bonding the conductor to said another electrical connector with glue.

43. A method according to claim 31 wherein the polymer is selected from the group consisting of polyaniline, polypyrrole, polythiphene, derivatives thereof, and mixtures of the foregoing.

44. A method according to claim 43 wherein the derivatives are selected from the group consisting of alkyl, alkoxy, amine and alcohol derivatives.

45. A method according to claim 31 wherein the conductor is a metal conductor.

46. A method according to claim 31 wherein the conductor is a wire.

47. An electrochemical actuator for effecting a desired action, comprising a tube of conducting polymer having a longitudinal passageway for receiving an electrolyte.

48. An electrochemical actuator according to claim 47 wherein the longitudinal passageway is a through passageway extending along the tube from one end region of the tube to an opposite end region of the tube.

49. An electrochemical actuator according to claim 48 further comprising an electrical connector in electrical contact with the one end region of the tube for facilitating connection of the polymer to an electrical circuit.

50. An electrochemical actuator according to claim 49 comprising a further electrical connector in electrical contact with the opposite end region of the tube.

51. An electrochemical actuator according to claim 47 wherein the polymer is selected from the group consisting of polyaniline, polypyrrole, polythiophene, derivatives thereof, and mixtures of the foregoing.

52. An electrochemical actuator according to claim 51 wherein the derivatives are selected from the group consisting of alkyl, alkoxy, amine and alcohol derivatives.

53. A method or providing an electrochemical actuator for effecting a desired action, comprising:

coating a template with a conducting polymer; and

removing the template to provide a tube of the polymer having a longitudinal passageway for receiving an electrolyte.

54. A method according to claim 53 wherein the longitudinal passageway is a through passageway extending along the tube from one end region of the tube to an opposite end region of the tube.

55. A method according to claim 53 further comprising connecting an electrical connector to the one end region of the tube for facilitating connection of the polymer to an electrical circuit.

56. A method according to claim 55 further comprising connecting a further electrical connector to the opposite end region of the tube.

57. A method according to claim 53 wherein the polymer is selected from the group consisting of polyaniline, polyprrole, polythiophene, derivatives thereof, and mixtures of the foregoing.

58. A method according to claim 57 wherein the derivatives are selected from the group consisting of alkyl, alkoxy, amine and alcohol derivatives of polyaniline, polypyrrole and polythiophene.

59. (Cancelled)