Adhesive microstructure and method of forming same

• US 20030124312A1
• Filed: 01/02/2002
• Published: 07/03/2003
• Est. Priority Date: 01/02/2002
• Status: Active Grant

• Current Assignee: Lewis & Clark College
• Original Assignee: Lewis & Clark College
• Inventors: Autumn, Kellar
• Granted Patent: US 7,335,271 B2
• Time in Patent Office: Days
• US Class Current: 428/141
• CPC Class Codes: B32B 3/266 characterised by an apertured layer, the apertures going through the whole thickness of the layer, e.g. expanded metal, perforated layer, slit layer regular cells B32B3/12
• 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: Y10T 156/10 Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 428/24355 Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]

Abstract

A fabricated microstructure includes a plurality of protrusions. The protrusions are capable of providing substantially parallel adhesive force at a surface of between about 60 and 2000 nano-Newtons. A flexible shaft supports the protrusions, and a flexible member or beam is attached to the shaft to form a manipulator or gripper device.

Claims

1. A fabricated microstructure comprising:

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

a flexible shaft to support said protrusions; and

a flexible beam to which said shaft is attached.

2. The fabricated microstructure of claim 1 wherein there are a plurality of shafts attached to said flexible beam, each of said shafts supporting a plurality of protrusions.

3. The fabricated microstructure of claim 1 wherein the shaft has a length of less than about 500 microns, and a diameter of between about 0.01 and 0.1 times the length of the shaft.

4. The fabricated microstructure of claim 3 wherein the shaft has a diameter of about 0.05 times the length of the shaft.

5. The fabricated microstructure of claim 1 wherein the shaft has a length of between about 10 and 100 microns.

6. The fabricated microstructure of claim 1 wherein said protrusions adhere to the surface by intermolecular forces.

7. The fabricated microstructure of claim 1 wherein the flexible beam has a length of between about 1 and 5 centimeters, a width of between about 0.5 and 1 centimeter, and a thickness of between about 0.1 and 0.3 millimeters.

8. The fabricated microstructure of claim 1 wherein said flexible beam produces between about 0.01 and 0.10 grams of a preload force while maintaining a substantially parallel alignment of the protrusions with a surface.

9. 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;

a shaft to support said array of protrusions; and

a flexible beam to which said shaft is attached.

10. A fabricated grip comprising:

a lamella from a specimen attached to a flexible beam and configured to engage an item to be manipulated.

11. The fabricated grip of claim 10 further including a substrate to support an object, said lamella attachable to the substrate to manipulate the object.

12. A fabricated microstructure comprising:

a shaft with a length of less than about 500 microns, said shaft having a diameter of between about 0.01 and 0.1 times the length of said shaft;

an array of spatulae formed at an end of said shaft, said array of spatulae having a width of less than about ten microns, individual spatula of said array having a terminal end to provide an adhesive force at a surface; and

a flexible beam to which said shaft is attached.

13. The fabricated microstructure of claim 12 wherein said shaft has a length of between approximately 10 and 100 microns.

14. The fabricated microstructure of claim 12 wherein said shaft has a diameter of approximately 0.05 times the length of said shaft.

15. The fabricated microstructure of claim 12 wherein said terminal end has a radius of approximately 2 microns.

16. The fabricated microstructure of claim 12 wherein the flexible beam has a length of between about 1 and 5 centimeters, a width of between about 0.5 and 1 centimeter, and a thickness of between about 0.1 and 0.3 millimeters.

17. The fabricated microstructure of claim 12 wherein said flexible beam produces between about 0.01 and 0.10 gram of a preload force while maintaining a substantially parallel alignment of the array of spatulae with the surface.

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

19. A method of forming an adhesive force, said method comprising the steps of:

attaching a seta from a specimen to a flexible beam; and

applying said seta to a surface so as to establish an adhesive force at said surface so the flexible beam can be used to manipulate an object.

20. The method of claim 19 further including removing a seta from a gecko.

21. The method of claim 19 further including removing a seta from a living specimen selected from the group consisting of species of Anolis, skinks, beetles, and kissing-bugs.

22. The method of claim 19 wherein said applying step includes the steps of:

applying said seta to said surface with a force perpendicular to said surface; and

pulling said seta with a force parallel to said surface so as to engage said adhesive force.

23. The method of claim 22 wherein said adhesive force is greater than the cumulative force of said applying and pulling steps.

24. A method of establishing an adhesive force, said method comprising the steps of:

using a flexible beam to apply a seta to a surface with a force perpendicular to said surface so as to preload an adhesive force of said seta;

using the flexible beam to orient said seta parallel to said surface; and

using the flexible beam to pull said setae with a force parallel to said surface.

25. The method of claim 24 wherein said adhesive force is greater than the cumulative force of said applying and pulling steps.

26. The method of claim 24 further comprising the step of eliminating said adhesive force by creating a force to produce a detachment angle between said seta and said surface.

27. The method of claim 26 wherein said eliminating step includes a step of creating a force to produce a detachment angle of between about 25°

and 35°

between said seta and said surface.

28. The method of claim 26 wherein said eliminating step includes the step of:

creating a force to produce a detachment angle of approximately 30°

between said seta and said surface.

29. The method of claim 24 wherein said flexible beam produces between about 0.01 and 0.10 gram of a preload force while maintaining a substantially parallel alignment of the seta with the surface.

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

fabricating an array of shafts;

forming spatulae on said array of shafts; and

attaching said array of shafts to a flexible member.

31. The method of claim 30 wherein said forming step includes the step of forming spatulae, wherein the terminal end of individual spatula of said spatulae include an extended surface.

32. The method of claim 30 wherein said forming step includes the steps of:

constructing spatulae; and

attaching said spatulae to said array of shafts.

33. A method of fabricating an adhesive microstructure comprising:

contacting a seta of a specimen with a semiconductor substrate and causing relative motion between the seta and the semiconductor substrate to remove the seta from the specimen; and

attaching the removed seta to a flexible beam so the flexible beam can be used to manipulate an object.

34. The method of claim 33 wherein the semiconductor substrate is a silicon or gallium arsenide wafer.

35. The method of claim 33 wherein the flexible beam is made from a material selected from the group consisting of acetate, nylon, acrylic, brass and spring steel.

36. A method of establishing an adhesive force, said method comprising the steps of:

using a flexible beam to apply a seta to a surface with a force perpendicular to said surface so as to preload an adhesive force of said seta;

using the flexible beam to orient said seta parallel to said surface; and

using the flexible beam to pull said seta at a velocity to increase an adhesive force exerted by said setae on said surface.