Devices, methods, and systems for harvesting energy in the body

• US 8,311,632 B2
• Filed: 02/25/2009
• Issued: 11/13/2012
• Est. Priority Date: 02/25/2008
• Status: Active Grant

• Current Assignee: Autonomic Technologies, Inc. (Ford Motor Company)
• Original Assignee: Autonomic Technologies, Inc. (Ford Motor Company)
• Inventors: Pless, Benjamin David, Boling, Carl Lance, Gibb, Barbara, Wingeier, Brett M., van der Heide, Adolf
• Primary Examiner(s): GETZOW, SCOTT M
• Application Number:
  US12/392,938
• Publication Number:
  US 20090216292A1
• Time in Patent Office: 1,357 Days
• Field of Search: 607 27- 29, 607/34, 607/35, 607/59, 607/60, 607/61
• US Class Current: 607/35
• CPC Class Codes: A61N 1/3785 generated by biological activity or substance, e.g. body movement
• CPC Class Codes: H02N 11/002 Generators
• CPC Class Codes: H02N 2/18 producing electrical output from mechanical input, e.g. generators for measurement devices G01

Abstract

In some embodiments, the power generator for converting mechanical energy to electrical energy is described may include a compressible element adapted and configured to be placed in an environment having a variable compressive force such as varying ambient pressures. The compressible element may be compressed by a force applied by the variable pressure to the compressible element. The power generator may further include a transducer that may be coupled to the compressible element and that may convert mechanical energy from the compression of the compressible element to electrical energy. In some embodiments, the power generator may be adapted to be an implantable power generator for converting mechanical energy from a patient to electrical energy, such that the compressible element adapted and configured to be placed between two adjacent tissue layers of the patient and to be compressed by a force applied from the two adjacent tissue layers to the compressible element.

Claims

1. A power generator for converting mechanical energy to electrical energy, the generator comprising:

a housing that defines a chamber;

a phase changing dielectric fluid contained within the chamber of the housing;

a moveable surface, coupled to the housing, that defines the volume of the phase changing dielectric fluid, wherein as the moveable surface moves from a first position toward a second position, the volume of the phase changing dielectric fluid is changed, such that the phase changing dielectric fluid transitions at least in part between a first phase with a first dielectric constant and a second phase with a second dielectric constant; and

a capacitor within the chamber of the housing, the capacitor comprising a first plate and a second plate that define a space between them that contains a portion of the phase changing dielectric fluid, wherein the plates have a first voltage across them when the dielectric fluid is in the first phase and have a second voltage across them when the dielectric fluid is in the second phase.

2. The power generator of claim 1, the housing further comprising a spring element that biases the movable surface toward the first position.

3. The power generator of claim 1, wherein moveable surface comprises a flexible surface.

4. The power generator of claim 1, wherein moveable surface comprises a bellows.

5. The power generator of claim 1, the housing further comprising a base, substantially opposite to the movable surface, wherein the moveable surface moves relative to the base.

6. The power generator of claim 5, wherein the base is adapted and configured to be coupled to a first tissue layer of a patient, and the moveable surface is adapted and configured to be coupled to a second adjacent tissue layer of a patient, wherein a force applied from the two adjacent tissue layers to the housing moves the movable surface with respect to the base and reduces the volume of the chamber.

7. The power generator of claim 6, wherein the first tissue layer is a firm tissue layer, the second tissue layer is a muscle layer, and the force applied to the housing is generated by the muscle contracting adjacent to the firm tissue layer.

8. The power generator of claim 6, wherein the first and second tissue layers are muscle layers within a muscle and the force applied to the housing is generated by the muscle contracting.

9. The power generator of claim 5, wherein the base is a substantially rigid surface and the moveable surface comprises a piston head.

10. The power generator of claim 9, wherein the movable surface defines first chamber and a second chamber within the housing and the capacitor is within the second chamber.

11. The power generator of claim 1, further comprising a circuit that collects electrical energy from the capacitor as the voltage transitions from the first voltage to the second voltage.

12. The power generator of claim 1, wherein the circuit further functions to apply a voltage to the plates when the dielectric fluid is in the first phase.

13. The power generator of claim 1, wherein the first phase is a gas phase and the second phase is a liquid phase.

14. The power generator of claim 13, wherein the ratio of second dielectric constant to first dielectric constant is greater than 5.

15. The power generator of claim 13, wherein the ratio of second dielectric constant to first dielectric constant is greater than 20.

16. The power generator of claim 1, wherein the first phase is a gas phase and the second phase is a solid phase.

17. The power generator of claim 1, wherein the first phase is a liquid phase and the second phase is a solid phase.

18. The power generator of claim 1, wherein the phase changing dielectric fluid is water.

19. The power generator of claim 1, the plates further comprising a surface treated to facilitate a phase change of the dielectric fluid.

20. The power generator of claim 1, the capacitor further comprising a non-conductive spacer between the plates.

21. The power generator of claim 20, wherein the non-conductive spacer is a porous material disposed between the two plates.

22. A power generator for converting mechanical energy to electrical energy, the generator comprising:

a housing that defines a chamber and comprises a movable surface;

a dielectric fluid contained within the chamber of the housing;

a capacitor within the chamber of the housing, the capacitor comprising;

a first and second plate, and

an insulator coupled to the first plate and disposed between the first plate and the second plate,

wherein at least one plate is coupled to a movable surface of the housing,

wherein the plates have a first voltage across them when a first amount of the dielectric fluid is between the insulator and the second plate, and have a second voltage across them when a second amount of the dielectric fluid is between the insulator and the second plate;

wherein the movable surface moves from a first position toward a second position and displaces the dielectric fluid such that the first amount of the dielectric fluid is greater than the second amount of the dielectric fluid, the housing further comprising a spring element that returns the movable surface to the first position, the spring element comprising a compliant portion coupled to the housing and a non-compliant portion, coupled to the compliant portion, wherein the non-compliant portion and the compliant portion define a fluid filled chamber.

23. The power generator of claim 22, wherein as a force is applied to the housing and the movable surface displaces the dielectric fluid, the dielectric fluid moves a portion of the compliant portion into the fluid filled chamber, thereby compressing the fluid in the chamber.

24. The power generator of claim 23, wherein when the force is no longer applied to the housing, the fluid in the chamber moves the portion of the compliant portion out of the fluid filled chamber, thereby replacing dielectric fluid between the insulator and the second plate.

25. A method for generating power, the method comprising:

positioning a capacitor in a phase changing dielectric fluid contained within a chamber, the capacitor comprising a first plate and a second plate that define a space between them that contains a portion of the phase changing dielectric fluid;

applying a first voltage to at least one of the plates of the capacitor;

changing the phase of the phase changing dielectric fluid such that it transitions at least in part between a first phase with a first dielectric constant and a second phase with a second dielectric constant;

collecting a second voltage from at least one of the plates of the capacitor, wherein the plates of the capacitor have the second voltage across them when the dielectric fluid is in the second phase.

26. The method of claim 25, the changing step further comprising changing the pressure of the phase changing dielectric fluid such that the phase changing dielectric fluid transitions at least in part between a first phase and a second phase.

27. The method of claim 26, the changing step further comprising applying a mechanical input to change the pressure of the phase changing dielectric fluid.

28. The method of claim 25, the changing step further comprising changing the temperature of the phase changing dielectric fluid such that the phase changing dielectric fluid transitions at least in part between a first phase and a second phase.

29. The method of claim 25, the changing step further comprising changing the volume of the phase changing dielectric fluid such that the phase changing dielectric fluid transitions at least in part between a first phase and a second phase.

30. The method of claim 29, the changing step further comprising applying a mechanical input to change the volume of the phase changing dielectric fluid.

31. The method of claim 25, the changing step further comprising applying an ultrasound signal to the phase changing dielectric fluid to change the phase of the phase changing dielectric fluid.

32. The method of claim 25, the changing step further comprising applying radiofrequency signal to the phase changing dielectric fluid to change the phase of the phase changing dielectric fluid.

33. The method of claim 25, the changing step further comprising applying a laser to the phase changing dielectric fluid to change the phase of the phase changing dielectric fluid.

34. The method of claim 25, the changing step further comprising changing the phase of the dielectric fluid such that it transitions at least in part between a gas phase and a liquid phase.

35. The method of claim 25, the changing step further comprising changing the phase of the dielectric fluid such that it transitions at least in part between a gas phase and a solid phase.

36. The method of claim 25, the changing step further comprising changing the phase of the dielectric fluid such that it transitions at least in part between a liquid phase and a solid phase.

37. An implantable power generator for converting mechanical energy from a patient to electrical energy, the generator comprising:

a compressible element adapted and configured to be placed between two adjacent tissue layers of the patient and to be compressed by a force applied from the two adjacent tissue layers to the compressible element, the compressible element comprising a substantially rigid base adapted and configured to be coupled to a first tissue layer, and a piston head, substantially opposite to the base, adapted and configured to be coupled to a second tissue layer, wherein the force applied from the two adjacent tissue layers to the compressible element moves the piston head with respect to the base; and

a transducer, coupled to the compressible element, that converts mechanical energy from the compression of the compressible element to electrical energy.

38. An implantable power generator for converting mechanical energy from a patient to electrical energy, the generator comprising:

a compressible element defining a chamber and comprising a fluid within the chamber, the compressible element adapted and configured to be placed between two adjacent tissue layers of the patient and to be compressed by a force applied from the two adjacent tissue layers to the compressible element, wherein, upon compression of the compressible element, the compressible element displaces the fluid from within the chamber of the compressible element, thereby generating a fluid pressure;

a transducer, coupled to the compressible element, that converts mechanical energy from the compression of the compressible element to electrical energy; and

a transmission, coupled to the compressible element and to the transducer, that transforms a motion from the compression of the compressible element into a rotational motion.

39. The implantable power generator of claim 38, the transmission further comprising a wheel that transforms a fluid pressure from the compression of the compressible element into a rotational motion.

40. The implantable power generator of claim 38, the transmission further comprising a rack and a pinion that transforms the motion from the compression of the compressible element into a rotational motion.

41. The implantable power generator of claim 38, the transmission further comprising a threaded spindle and a threaded cylinder, coupled to the threaded spindle, that transforms the motion from the compression of the compressible element into a rotational motion.

42. The implantable power generator of claim 38, the transducer comprising an electromagnetic generator coupled to the transmission.

43. The implantable power generator of claim 42, wherein the rotational motion from the transmission drives the electromagnetic generator, such that the electromagnetic generator converts the rotational motion to electrical energy.

44. The implantable power generator of claim 38, the compressible element further comprising a flexible housing and a structural member, coupled to the housing and to the transducer, that transmits a force from the housing to the transducer such that, upon compression of the compressible element, the housing compresses and the structural member applies a tension force to the transducer, the structural member comprising three substantially rigid members, disposed within the housing, wherein upon compression of the compressible element, the housing compresses and the structural member transitions from a triangular arrangement having a first perimeter to a substantially horizontal arrangement having a second perimeter.

45. The implantable power generator of claim 44, wherein the transducer is coupled to the structural member such that upon compression of the compressible element, the structural member applies a tension force to the transducer, such that the transducer transitions from a first perimeter to a second perimeter.

46. The implantable power generator of claim 45, the transducer comprising an electroactive polymer that has a first capacitance in the first perimeter and a second capacitance in the second perimeter.

47. An implantable power generator for converting mechanical energy from a patient to electrical energy, the generator comprising:

a compressible element adapted and configured to be placed between two adjacent tissue layers of the patient and to be compressed by a force applied from the two adjacent tissue layers to the compressible element, the compressible element defining a chamber and further comprising a fluid within the chamber; and

a transducer, coupled to the compressible element, the transducer comprising a capacitor within the chamber, having a first plate and a second plate, wherein the fluid is a phase changing dielectric fluid and the plates have a first voltage across them when the dielectric fluid is in a first phase and have a second voltage across them when the dielectric fluid is in a second phase, wherein the transducer converts mechanical energy from the compression of the compressible element to electrical energy.

48. The implantable power generator of claim 47, the compressible element comprising:

a base adapted and configured to be coupled to the first tissue layer; and

a moveable surface, substantially opposite to the base, adapted and configured to be coupled to the second tissue layer;

wherein the base and the movable surface define the volume of the chamber, and the force applied from the two adjacent tissue layers to the compressible element moves the movable surface with respect to the base, such that the volume of the phase changing dielectric fluid is changed and the phase changing dielectric fluid transitions between the first phase with a first dielectric constant and the second phase with a second dielectric constant.

49. The power generator of claim 47, further comprising a circuit that collects electrical energy from the capacitor as the voltage transitions from the first voltage to the second voltage.

50. The power generator of claim 49, wherein the circuit further functions to apply a voltage to the plates when the dielectric fluid is in the first phase.

51. The power generator of claim 47, wherein the first phase is a gas phase and the second phase is a liquid phase.

52. The power generator of claim 51, wherein the ratio of second dielectric constant to first dielectric constant is greater than 5.

53. The power generator of claim 51, wherein the ratio of second dielectric constant to first dielectric constant is greater than 20.

54. The power generator of claim 47, wherein the phase changing dielectric fluid is water.

55. The implantable power generator of claim 48, wherein the base is a substantially rigid surface and the moveable surface comprises a piston head.

56. The power generator of claim 55, wherein the movable surface defines a first chamber and a second chamber within the housing and the capacitor is within the second chamber.