Dry adhesives and methods for making dry adhesives

1. A method of forming a dry adhesive fiber in a structure including an etch layer and a barrier layer, wherein the etch layer and the barrier layer are adjacent to each other and are made from different materials, wherein the etch layer includes a surface of the etch layer opposite the barrier layer, comprising:

forming an opening through the etch layer to the barrier layer;

filling the opening with a material;

removing the barrier layer from the material in the opening; and

removing the etch layer from the material.

2. The method of claim 1 , wherein the step of filling the opening with a material includes filling the opening with a polymer.

3. The method of claim 1 , wherein the step of filling the opening with a material includes filling the opening with a material under vacuum.

4. The method of claim 1 , wherein the step of removing the etch layer comprises the step of removing the etch layer with a dry etch.

5. The method of claim 1 , wherein the material in the opening is selected from the group consisting of liquid polymer and gas phase polymer.

6. The method of claim 1 , further comprising the step of expanding the opening in the etch layer adjacent to the surface of the etch layer to form an expanded opening in the surface of the etch layer before the step of filling the opening with the material, wherein the opening in the etch layer extends between the expanded opening in the surface of the etch layer and the barrier layer.

7. The method according to claim 1 , further comprising the step of applying a hydrophobic material to a side wall of the opening prior to the step of filling the opening with a material.

8. The method according to claim 1 , further comprising the step of forming a fluorocarbon layer to a surface of the barrier layer adjacent to the opening prior to the step of filling the opening with a material, wherein a portion of the fluorocarbon layer is deposited on a flat surface of the material adjacent the surface of the barrier layer to form a dry adhesive fiber tip while removing the etch layer by a dry etch.

9. The method according to claim 1 , wherein the barrier layer is silicon oxide.

10. The method according to claim 1 , wherein the structure further comprises a substrate attached to the barrier layer, and further comprises the step of removing the substrate from the barrier layer before the step of removing the barrier layer from the material in the opening.

11. The method according to claim 1 , wherein the step of forming the opening through the etch layer to the barrier layer further comprises the step of using an electron beam to form the opening.

12. The method according to claim 1 , further comprising the step of expanding the opening in the etch layer adjacent to the barrier layer prior to the step of filling the opening with the material.

13. The method of claim 12 , wherein expanding the opening in the etch layer adjacent to the barrier layer further comprises the step of removing the etch layer with a dry etch.

14. The method according to claim 1 , wherein the step of forming the opening through the etch layer to the barrier layer comprises:

forming a pattern on the surface of the etch layer to define an exposed etch layer, and

removing the exposed etch layer.

15. The method according to claim 14 , wherein the step of removing the exposed etch layer comprises the step of exposing the structure to an etching process.

16. The method according to claim 15 , further comprising the step of removing the pattern after the step of removing the exposed etch layer.

17. A method of forming a dry adhesive fiber array in a first structure including an etch layer and a barrier layer, wherein the etch layer and the barrier layer are adjacent to each other and are made from different materials, wherein the etch layer includes a surface of the etch layer opposite the barrier layer, comprising:

forming a plurality of openings through the etch layer [[and ]]to the barrier layer;

filling openings of the plurality of openings with a material;

removing the barrier layer from the material in the openings of the plurality of openings; and

removing the etch layer from the material in the openings of the plurality of openings.

18. The method of claim 17 , further comprising the step of forming a backing layer is formed from the material used in the openings.

19. The method of claim 17 , further comprising the step of expanding the openings of the plurality of openings in the etch layer adjacent to the surface of the etch layer to form expanded openings in the surface of the etch layer before the step of filling the plurality of openings with the material, wherein the openings of the plurality of openings in the etch layer extend between the expanded openings in the surface of the etch layer and the barrier layer.

20. The method according to claim 17 , further comprising the steps after the step of filling the openings of the plurality of openings with the material:

forming a backing layer over the openings of the plurality of

openings and on the surface of the etch layer opposite the

barrier layer, wherein the material in the openings of the

plurality of the openings is connected via the backing layer; and

removing the etch layer from the backing layer.

21. The method according to claim 17 , further comprising the step of expanding openings of the plurality of openings in the etch layer adjacent to the barrier layer prior to the step of filling the openings of the plurality of openings with the material.

22. A method of forming a dry adhesive multi-layer fiber arrays with a first structure including a first etch layer and a first barrier layer, wherein the first etch layer and the first barrier layer are adjacent to each other and are made from different materials, wherein the first etch layer includes a first surface of the first etch layer opposite the first barrier layer, and a second structure including a second etch layer and a second barrier layer, wherein the second etch layer and the second barrier layer are adjacent to each other and are made from different materials, wherein the second etch layer includes a second surface of the second etch layer opposite the second barrier layer, comprising the steps of:

forming a first plurality of openings through the first etch layer to the first barrier layer of the first structure;

forming a second plurality of openings through the second etch layer to the second barrier layer of the second structure, wherein a cross-section of at least one opening of the second plurality of openings is smaller than a cross-section of the at least one opening of the first plurality of openings;

connecting the first structure to the second structure such that at least one opening of the second plurality of openings corresponds to at least one opening of the first plurality of openings;

removing the first barrier layer from the first etch layer; filling the first and second plurality of openings with a material; removing the second barrier layer from the second etch layer; and removing the first and second etch layers surrounding the material in the openings of the first and second plurality of openings to form the dry adhesive multi-layer fiber arrays.

23. The method of claim 22 , wherein connecting the first and second structures includes silicon fusion bonding.

24. The method according to claim 22 , further comprising the step of forming a backing layer over the first plurality of openings and on the first surface of the first etch layer after the step of filling the first and second plurality of openings with a material, wherein the material in the first plurality of the openings is connected thereto via the backing layer.

25. The method according to claim 22 , wherein the step of filling the first and second plurality of openings with the material further comprises the step of filling the first and second plurality of openings with the material to a predetermined level such that none of the material extends out of the openings of the first plurality of openings to form a backing layer.

26. The method of claim 22 , further comprising the step of expanding the at least one opening of the second plurality of openings in the second etch layer adjacent to the second surface of the second etch layer to form an expanded second surface opening in the second surface of the second etch layer before the step of connecting the first structure to the second structure, wherein the second plurality of openings in the second etch layer extend between the expanded second surface opening in the second surface of the second etch layer and the second barrier layer.

27. The method according to claim 22 , further comprising the step of expanding the at least one opening of the second plurality of openings in the second etch layer adjacent to the second barrier layer to form an expanded second opening prior to the step of connecting the first structure to the second structure.

28. The method according to claim 22 , wherein the at least one opening of the first plurality of openings further comprises an end adjacent to the first barrier layer to form a barrier layer end of the at least one opening of the first plurality of openings, and wherein the method further comprises the step of expanding the barrier layer end of the at least one opening of the first plurality of openings.

29. The method according to claim 22 , wherein the step of connecting the first structure to the second structure further comprising the step of connecting the first surface of the first etched layer of the first structure directly to the second surface of the second etched layer of the second structure.

30. The method according to claim 22 ,

further comprising the step of expanding the at least one opening of the first plurality of openings in the first etch layer adjacent to the first surface of the first etch layer to form an expanded first surface opening in the first surface of the first etch layer before the step of connecting the first structure to the second structure;

further comprising the step of expanding the at least one opening of the second plurality of openings in the second etch layer adjacent to the second surface of the second etch layer to form an expanded second surface opening in the second surface of the second etch layer before the step of connecting the first structure to the second structure; and

wherein the step of connecting the first structure to the second structure further comprises connecting the second surface of the second etched layer directly to the first surface of the first structure such that the expanded second surface of the at least one opening of the second plurality of openings in the second etch layer directly corresponds with the expanded first surface opening of the at least one opening of the first plurality of openings in the first etch layer of the first structure.

31. The method of claim 22 , further comprising the step of expanding the at least one opening of the second plurality of openings in the second etch layer adjacent to the second barrier layer to form an expanded second barrier layer opening in the at least one opening of the second plurality of opening of the second etch layer before the step of connecting the first structure to the second structure.

32. The method according to claim 22 ,

further comprising the step of expanding the at least one opening of the first plurality of openings in the first etch layer adjacent to the first surface of the first etch layer to form an expanded first surface opening in the first surface of the first etch layer before the step of connecting the first structure to the second structure;

further comprising the step of expanding the at least one opening of the second plurality of openings in the second etch layer adjacent to the second barrier layer to form an expanded second barrier layer opening in the at least one opening of the second plurality of openings of the second etch layer before the step of connecting the first structure to the second structure; and

wherein the step of connecting the first structure to the second structure further comprises connecting the second surface of the second etched layer directly to the first surface of the first structure such that the at least one opening of the second plurality of openings corresponding to the second surface of the second etch layer is adjacent to the expanded first surface opening of the at least one opening of the first plurality of openings in the first etch layer of the first structure.

33. The method according to claim 22 , further comprising the step of removing the first surface from the first etch layer.

34. The method according to claim 22 , further comprising the step of removing the second surface from the second etch layer.

35. The method of claim 22 , further comprising the step of expanding the at least one opening of the first plurality of openings in the first etch layer adjacent to the first surface of the first etch layer to form an expanded first surface opening in the first surface of the first etch layer before the step of connecting the first structure to the second structure, wherein the at least one opening of the first plurality of openings in the first etch layer extend between the expanded first surface opening in the first surface of the first etch layer and the first barrier layer.

36. The method according to claim 35 , wherein the step of connecting the first structure to the second structure further comprises connecting the first surface of the first etched layer directly to the second structure such that the expanded first surface opening is directly adjacent to the at least one opening of the second plurality of openings of the second structure.

37. The method according to claim 22 , wherein the at least one opening of the second plurality of openings further comprises an end adjacent to the second surface of the second etch layer to form a second surface end of the at least one opening of the second plurality of openings, and wherein the step of connecting the first structure to the second structure comprises connecting the step of the second surface of the second etched layer directly to the first structure such that the second surface end of the at least one opening of the second plurality of openings directly adjacent to the at least one opening of the first plurality of openings of the first structure.

38. The method according to claim 37 , further comprising the step of expanding the second surface end of the at least one opening of the second plurality of openings to form an expanded second surface opening prior to the step of connecting the first structure to the second structure.