Adhesive microstructure and method of forming same

• US 6,872,439 B2
• Filed: 07/17/2002
• Issued: 03/29/2005
• Est. Priority Date: 05/13/2002
• Status: Expired due to Term

• 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., Sitti, Metin
• Primary Examiner(s): Watkins, III, William P.
• Application Number:
  US10/197,763
• Publication Number:
  US 20030208888A1
• Time in Patent Office: 986 Days
• Field of Search: 244/46, 244/42, 428/119, 428/141, 428/343, 428/364, 428/399, 428/400, 428/99, 428/397, 428/401, 428/85, 428/90, 264/219, 264/299, 264/222, 977/DIG.1
• US Class Current: 428/99
• CPC Class Codes: A44B 18/0003 Fastener constructions A44B18/0023, A44B18/0046 take precedence
• CPC Class Codes: A44B 18/0049 obtained by moulding processes compression moulding or articles of indefinite length characterised by the shape of the surface B29C43/222; screen moulding B29C67/08
• CPC Class Codes: A44B 18/0061 Male or hook elements A44B18/0053 takes precedence
• CPC Class Codes: B08B 1/00 Cleaning by methods involving the use of tools cleaning hollow articles by methods or apparatus specially adapted thereto B08B9/00
• CPC Class Codes: B08B 1/10 characterised by the type of cleaning tool
• CPC Class Codes: B08B 7/0028 by adhesive surfaces
• CPC Class Codes: B29C 33/42 characterised by the shape of the moulding surface, e.g. ribs or grooves
• CPC Class Codes: B29L 2031/756 Microarticles, nanoarticles
• CPC Class Codes: B81B 2203/0361 Tips, pillars
• CPC Class Codes: B81B 3/0059 Constitution or structural means for controlling the movement not provided for in groups B81B3/0037 - B81B3/0056
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C09J 2301/31 the adhesive effect being based on a Gecko structure
• CPC Class Codes: C09J 7/00 Adhesives in the form of films or foils
• CPC Class Codes: F16B 2/005 Means to increase the friction-coefficient
• CPC Class Codes: F16B 5/07 by means of multiple interengaging protrusions on the surfaces, e.g. hooks, coils,
• CPC Class Codes: Y10S 977/84 Manufacture, treatment, or detection of nanostructure
• 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 24/2742 having filaments of varied shape or size on same mounting surface
• CPC Class Codes: Y10T 428/23943 Flock surface
• CPC Class Codes: Y10T 428/24008 including fastener for attaching to external surface
• CPC Class Codes: Y10T 428/24174 : including sheet or component perpendicular to plane of web or sheet
• CPC Class Codes: Y10T 428/24355 : Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
• CPC Class Codes: Y10T 428/28 : Web or sheet containing structurally defined element or component and having an adhesive outermost layer
• CPC Class Codes: Y10T 428/2913 : Rod, strand, filament or fiber
• CPC Class Codes: Y10T 428/2973 : Particular cross section
• CPC Class Codes: Y10T 428/2976 : Longitudinally varying
• CPC Class Codes: Y10T 428/2978 : Surface characteristic
• CPC Class Codes: Y10T 428/298 : Physical dimension

Abstract

A fabricated microstructure comprising at least one protrusion capable of providing an adhesive force at a surface of between about 60 and 2,000 nano-Newtons. A stalk supports the protrusion at an oblique angle relative to a supporting surface. The microstructure can adhere to different surfaces.

Claims

1. A fabricated microstructure comprising:

at least one protrusion capable of providing an adhesive force at a surface of between about 60 and 2,000 nano-Newtons;

a stalk to support said protrusion at an oblique angle relative to a supporting surface; and

wherein the microstructure is capable of adhering to different surfaces.

2. A fabricated microstructure comprising:

a plurality of protrusions, each protrusion capable of providing an adhesive force at a surface of between about 60 and 2,000 nano-Newtons; and

a stalk to support each of said protrusions at an oblique angle relative to a supporting structure.

3. The fabricated microstructure of claim 2 wherein the stalk has a length of between about 0.5 and 20 microns, and a diameter of between about 50 nanometers and 2.0 microns.

4. The fabricated microstructure of claim 2 wherein said protrusions adhere to the surface by intermolecular forces.

5. The fabricated microstructure of claim 2 wherein the oblique angle is between about 15 and 75 degrees.

6. The fabricated microstructure of claim 5 wherein the oblique angle is between about 30 and 60 degrees.

7. The fabricated microstructure of claim 5 wherein the oblique angle is about 30 degrees.

8. A fabricated microstructure comprising:

an array of protrusions, said array having a width less than about ten microns and each protrusion of said array capable of providing an adhesive force at a surface by intermolecular forces; and

a stalk to support each of said protrusions at an oblique angle relative to a supporting shaft.

9. The fabricated microstructure of claim 8 wherein the stalk has a length of between about 0.5 and 20 microns, and a diameter of between about 50 nanometers and 2.0 microns.

10. The fabricated microstructure of claim 9 wherein the shaft has a length of between about 1 and 500 microns, and a diameter of between about 1 and 10 microns.

11. A fabricated microstructure comprising:

an array of members;

each member supporting a protrusion at an oblique angle relative to a supporting surface; and

wherein each protrusion is capable of providing an adhesive force at a surface of between about 60 and 2,000 nano-Newtons.

12. The fabricated microstructure of claim 11 wherein a terminal end of the protrusion has a shape selected from the group consisting of a curved segment of a sphere, a flattened segment of a sphere, a sphere, a flattened surface, and an end of a cylinder.

13. A fabricated microstructure comprising:

an array of stalks;

said stalks having a diameter of between about 50 nanometers and 2.0 microns, and a length of between about 0.5 microns and 20 microns;

each stalk supporting a spatula at an oblique angle relative to a supporting surface; and

the spatula having a terminal end that provides an adhesive force.

14. A fabricated microstructure comprising:

a plurality of shafts extending at an oblique angle from a supporting surface;

a plurality of stalks extending at an oblique angle from an end of the shafts opposite the shaft ends adjacent the supporting surface;

at least one protrusion formed at an end of the stalks opposite the stalk ends adjacent the shafts; and

wherein the protrusion is capable of providing an adhesive force at a surface by intermolecular forces.

15. The fabricated microstructure of claim 14 wherein the diameter of the shafts is between about 1 and 10 microns, and the length of the shafts is between about 1 and 500 microns.

16. The fabricated microstructure of claim 15 wherein the diameter of the stalks is between about 50 nanometers and 2.0 microns, and the length of the stalks is between about 0.5 and 20 microns.

17. The fabricated microstructure of claim 14 wherein the angle from which the stalks extend from the shafts is between about 15 and 75 degrees.

18. The fabricated microstructure of claim 17 wherein the angle from which the stalks extend from the shafts is between about 30 and 60 degrees.

19. The fabricated microstructure of claim 17 wherein the angle from which the stalks extend from the shafts is about 30 degrees.

20. The fabricated microstructure of claim 14 wherein the supporting surface is flexible.

21. The fabricated microstructure of claim 14 wherein a terminal end of the protrusion is capable of providing an adhesive force of between 60 and 2,000 nano-Newtons.

22. The fabricated microstructure of claim 14 wherein the protrusion has a Young'"'"'s modulus of between about 0.1 and 20 giga-Pascals.

23. The fabricated microstructure of claim 14 wherein the protrusion is hydrophobic.

24. A method of fabricating an adhesive microstructure, said method comprising the steps of:

fabricating an array of stalks; and

said array of stalks formed such that the stalks support a protrusion obliquely relative to a supporting surface wherein the protrusion can provide an adhesive force of between about 60 and 2,000 nano-Newtons at a surface.

25. The method of claim 24 wherein said fabricating step includes the step of constructing said array of stalks using a template.

26. The method of claim 25 wherein said fabricating step includes molding said template with a polymer.

27. The method of claim 26 wherein said template is sheared under stress and a temperature to deform it.

28. The method of claim 26 wherein each side of said template is polished at an angle.

29. The method of claim 24 wherein said fabricating step includes the step of constructing said array of shafts using an imprinting technique.