Structure having nano-fibers on annular curved surface, method of making same and method of using same to adhere to a surface

• US 7,175,723 B2
• Filed: 10/04/2004
• Issued: 02/13/2007
• Est. Priority Date: 10/03/2003
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Fearing, Ronald S., Jones, Steven D.
• Primary Examiner(s): Maki; Steven D.
• Application Number:
  US10/958,476
• Publication Number:
  US 20050092414A1
• Time in Patent Office: 862 Days
• Field of Search: 156/60, 156/160, 152/209.4, 152/212, 36/59.C, 428/92
• US Class Current: 156/60
• CPC Class Codes: B29D 2030/665 Treads containing inserts other than spikes, e.g. fibers or hard granules, providing antiskid properties
• CPC Class Codes: B29D 30/66 Moulding treads on to tyre casings, e.g. non-skid treads with spikes
• CPC Class Codes: B60C 1/0016 Compositions of the tread
• CPC Class Codes: B60C 11/00 Tyre tread bands; Tread patterns; Anti-skid inserts
• CPC Class Codes: B60C 11/14 Anti-skid inserts, e.g. vulcanised into the tread band
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C08K 2201/011 Nanostructured additives
• CPC Class Codes: C08K 7/02 Fibres or whiskers
• CPC Class Codes: C08L 21/00 Compositions of unspecified rubbers
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 428/23929 Edge feature or configured or discontinuous surface
• CPC Class Codes: Y10T 428/23936 Differential pile length or surface
• CPC Class Codes: Y10T 428/23943 Flock surface
• CPC Class Codes: Y10T 428/23957 Particular shape or structure of pile
• CPC Class Codes: Y10T 428/24628 Nonplanar uniform thickness material

Abstract

A curved surfaces for adhering to contact surfaces is provided. The structure includes a curved surface with a plurality of nano-fibers disposed thereon. When the curved surface is in a first position, at least one of the plurality of nano-fibers contacts the contact surface and provides an adhesive force at the contact surface. When the curved surface rotates to a second position from the first position, the at least one of the plurality of nano-fibers is leveraged way from the contact surface.

Claims

1. A structure for adhering to a contact surface comprising:

an annular curved surface rotatable about an axis of rotation; and

a plurality of nano-fibers disposed on the curved surface, each nano-fiber having a diameter between 50 nanometers and 2.0 microns and a length between 0.5 microns and 20 microns,

wherein the curved surface is configured to rotate from a first position to at least a second position,

wherein when the curved surface is in the first position, at least a first nano-fiber of the plurality of nano-fibers contacts the contact surface and provides an adhesive force at the contact surface, and at least a second nano-fiber of the plurality of nano-fibers is unattached to the contact surface; and

wherein when the curved surface rotates to the second position from the first position, at least the first nano-fiber is leveraged away from the contact surface, and at least the second nano-fiber contacts the contact surface and provides an adhesive force at the contact surface, and

wherein the first and second nano-fibers are oriented at an oblique angle other than 0 degrees and 90 degrees with respect to the annular curved surface when unattached to the contact surface and extend in the circumferential direction of the annular curved surface.

2. The structure of claim 1, wherein the first and the second nano-fibers are each capable of providing an adhesive force with the contact surface of between 0.06 μ

N and 0.20 μ

N.

3. The structure of claim 1, wherein the first and the second nano-fibers are each at an angle between 15 and 75 degrees relative to the curved surface when unattached to the contact surface.

4. The structure of claim 3, wherein the first and the second nano-fibers are each at an angle between 30 and 60 degrees relative to the curved surface when unattached to the contact surface.

5. The structure of claim 1, wherein the first nano-fiber adheres to the contact surface at the front portion of a contact patch, and the second nano-fiber adheres to the rear portion of the contact patch.

6. The structure of claim 1, wherein the annular curved surface is at least a portion of a wheel.

7. The structure of claim 1, wherein the plurality of nano-fibers extend from the annular curved surface in a single direction relative to the annular curved surface.

8. The structure of claim 1, wherein a first group of said nano-fibers at a first region of the annular curved surface extends from the annular curved surface in a first direction relative to he annular curved surface, and a second group of said nano-fibers disposed on a second region of the annular curved surface extends from the annular curved surface in a second direction relative to the annular curved surface.

9. The structure of claim 1, wherein the annular curved surface includes one or more raised sections, and at least one said nano-fiber has a base and is disposed on the curved surface outside the raised sections such that the base of the at least one nano-fiber does not contact the contact surface during rotation.

10. The structure of claim 9, wherein two said raised sections form a groove therebetween, and the at least one nano-fiber is disposed on the annular curved surface in the groove.

11. The structure of claim 1, wherein the first and the second nano-fibers are each capable of providing an adhesive force with the contact surface of between 0.01 μ

N and 0.20 μ

N.

12. A tire comprising:

a curved tire surface; and

a plurality of nano-fibers disposed on the curved tire surface, each nano-fiber having a diameter between 50 nanometers and 2.0 microns and a length between 0.5 microns and 20 microns, and each nano-fiber capable of providing an adhesive force at a contact surface, and wherein the plurality of nano-fibers comprise at least a first nano-fiber and at least a second nano-fiber, and wherein each of the first and second nano-fibers are oriented at an oblique angle other than 0 degrees and 90 degrees with respect to the curved surface of the tire and extend in the circumferential direction of the tire, and wherein when the tire is in a first position, at least the first nano-fiber contacts the contact surface and provides an adhesive force at the contact surface and at least the second nano-fiber is unattached to the contact surface, and when the tire rotates to a second position from the first position, at least the first nano-fiber is leveraged away from the contact surface and at least the second nano-fiber contacts the surface and provides an adhesive force at the contact surface.

13. The tire of claim 12, wherein the first and the second nano-fibers are each capable of providing an adhesive force with the contact surface of between 0.06 μ

N and 0.20 μ

N.

14. The tire of claim 12, wherein the first and the second nano-fibers are each at an angle between 15 and 75 degrees relative to the tire surface.

15. The tire of claim 14, wherein the first and the second nano-fibers are each at an angle between 30 and 60 degrees relative to the tire surface.

16. The tire of claim 12, wherein the first nano-fiber adheres to the contact surface at the front portion of a contact patch, and the second nano-fiber adheres to the rear portion of the contact patch.

17. The tire of claim 12, wherein the tire includes two raised sections, wherein the plurality of nano-fibers is disposed between the two raised sections.

18. The tire of claim 12, wherein the tire includes at least one raised section, and wherein the plurality of nano-fibers is disposed around the base of the raised section.

19. The tire of claim 12, wherein the plurality of nano-fibers extend from the curved surface of the wheel in a single direction relative to the curved surface.

20. The tire of claim 12, wherein a first group of said nano-fibers at a first region of the curved surface extends from the curved surface in a first direction relative to the curved surface, and a second group of said nano-fibers disposed on a second region of the curved surface extends from the curved surface in a second direction relative to the curved surface.

21. The tire of claim 12, wherein the frictional properties of the tire are enhanced by intermolecular forces at each nano-fiber.

22. The tire of claim 21, wherein intermolecular forces are van der Waal'"'"'s interactions.

23. The tire of claim 12, wherein the first and the second nano-fibers are each capable of providing an adhesive force with the contact surface of between 0.01 μ

N and 0.20 μ

N.

24. A method of moving a curved surface over a contact surface comprising:

providing one or more nano-fibers disposed on the curved surface, each nano-fiber having a diameter between 50 nanometers and 2.0 microns and a length between 0.5 microns and 20 microns, and each nano-fiber capable of providing an adhesive force at the contact surface, wherein the curved surface is an annular curved surface rotatable about an axis of rotation; and

rotating the curved surface along the contact surface to cause at least one nano-fiber to adhere to the contact surface,

wherein the curved surface is configured to rotate from a first position to at least a second position,

wherein when the curved surface is in the first position, a first nano-fiber contacts the contact surface and provides an adhesive force at the contact surface, and a second nano-fiber is unattached to the contact surface, and

wherein when the curved surface rotates to the second position from the first position, the first nano-fiber is leveraged away from the contact surface, and the second nano-fiber contacts the contact surface and provides an adhesive force at the contact surface, and

wherein the first and second nano-fibers are oriented at an oblique angle other than 0 degrees and 90 degrees with respect to the annular curved surface when unattached to the contact surface and extend in the circumferential direction of the annular curved surface.

25. The method of claim 24, wherein the first and second nano-fibers each engages the contact surface first in the direction normal to the contact surface and second in the lateral direction along the contact surface.

26. The method of claim 24, wherein the first and the second nano-fibers are each capable of providing an adhesive force with the contact surface of between 0.06 μ

N and 0.20 μ

N.

27. The method of claim 24, wherein the first and second nano-fibers are each at each at an angle between 15 and 75 degrees relative to the curved surface.

28. The method of claim 24, wherein the first and second nano-fibers are each at an angle between 30 and 60 degrees relative to the curved surface.

29. The method of claim 24, wherein the first nano-fiber adheres to the contact surface at the front portion of the contact patch, and the second nano-fiber adheres to the rear portion of the contact patch.

30. The method of claim 24, wherein the plurality of nano-fibers extend from the curved surface in a single direction relative to the curved surface.

31. The method of claim 24, wherein a first group of said nano-fibers at a first region of the curved surface extends from the curved surface in a first direction relative to the curved surface, and a second group of said nano-fibers disposed on a second region of the curved surface extends from the curved surface in a second direction relative to the curved surface.

32. The method of claim 24, wherein the curved surface includes one or more raised sections, and wherein the one or more nano fibers comprise a base, and at least one said nano-fiber is disposed on the curved surface outside the raised sections such that the base of the at least one nano-fiber does not contact the contact surface during rotation.

33. The method of claim 32, wherein two said raised sections form a groove therebetween, and the at least one nano-fiber is disposed on the curved surface in the groove.

34. The method of claim 24, wherein the first and the second nano-fibers are each capable of providing an adhesive force with the contact surface of between 0.01 μ

N and 0.20 μ

N.

35. A method of making a structure for adhering to a contact surface comprising:

forming a curved surface, wherein the curved surface is configured to rotate from a first position to at least a second position, wherein the curved surface is an annular curved surface rotatable about an axis of rotation;

forming a plurality of nano-fibers having a diameter between 50 nanometers and 2.0 microns and a length between 0.5 microns and 20 microns on said surface, wherein the first and second nano-fibers are oriented at an oblique angle other than 0 degrees and 90 degrees with respect to the annular curved surface and extend in the circumferential direction the annular curved surface; and

placing the plurality of nano-fibers on the curved surface,

wherein when the curved surface is in the first position, a first nano-fiber of the plurality of nano-fibers contacts the contact surface and provides an adhesive force at the contact surface, and a second nano-fiber of the plurality of nano-fibers is unattached to the contact surface, and

wherein when the curved surface rotates to the second position from the first position, the first nano-fiber is leveraged away from the contact surface, and the second nano-fiber contacts the contact surface and provides an adhesive force at the contact surface.

36. The method of claim 35, wherein the curved surface is a portion of a wheel.

37. The method of claim 35, wherein the curved surface is a tire.

38. The method of claim 35, wherein the first and the second nano-fibers are each capable of providing an adhesive force with the contact surface of between 0.01 μ

N and 0.20 μ

N.