DRY ADHESIVES AND METHODS FOR MAKING DRY ADHESIVES
A dry adhesive and a method of forming a dry adhesive. The method includes forming an opening through an etch layer and to a barrier layer, expanding the opening in the etch layer at 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 in the opening.
1 . A dry adhesive fiber structure, comprising:
a dry adhesive fiber including:
a tip having a surface and an end opposite the surface; and
a stem having (i) a distal end connected to the end of the tip at a tip point of connection, (ii) a proximal end opposite the distal end, (iii) a longitudinal length from the distal end to the proximal end, and (iv) a plurality of cross-sectional areas along the longitudinal length.
2 . The dry adhesive fiber structure according to claim 1 , wherein the surface further comprises a flat surface.
3 . The dry adhesive fiber structure according to claim 1 ,
wherein the tip further comprises a plurality of tip cross-sectional areas;
wherein the plurality of tip cross-sectional areas increase from the tip point of connection to the surface of the tip;
wherein the stem further comprises a stem cross-sectional area of the plurality of cross-sectional areas at the tip point of connection; and
wherein the stem cross-sectional area of the stem at the tip point of connection is equal to or less than a tip cross-sectional area of the plurality of tip cross-sectional areas of the tip at the tip point of connection.
4 . The dry adhesive fiber structure according to claim 1 , wherein the plurality of cross sectional areas of the stem have same cross sectional areas to form a uniform stem cross-sectional area along the longitudinal length.
5 . The dry adhesive fiber structure according to claim 1 , wherein the plurality of cross sectional areas of the stem have different cross sectional areas to form a non-uniform stem cross-sectional area along the longitudinal length.
6 . The dry adhesive fiber structure according to claim 1 , further comprising a backing layer connected to the proximal end of the stem.
7 . The adhesive fiber array according to claim 6 , further comprising an angle between the stem and the backing layer being equal to 90 degrees.
8 . The adhesive fiber array according to claim 6 , further comprising an angle between the stem and the backing layer not being equal to 90 degrees.
9 . The adhesive fiber array according to claim 1 , further comprising an angle between the tip and the stem being equal to 90 degrees.
10 . The adhesive fiber array according to claim 1 , further comprising an angle between the tip and the stem not being equal to 90 degrees.
11 . The dry adhesive fiber structure according to claim 1 , wherein the surface of the tip comprises a layer of fluorocarbon.
12 . The dry adhesive fiber structure according to claim 1 ,
further comprising a base having a flat surface, an end opposite of the flat surface, and a plurality of base cross-sectional areas,
wherein the end of the base is connected to the proximal end of the stem at a base point of connection,
wherein the plurality of base cross-sectional areas increase from the base point of connection to the flat surface of the base;
wherein the stem further comprises a stem cross-sectional area at the base point of connection; and
wherein the stem cross-sectional area at the base point of connection is equal to or less than a base cross-sectional area of the plurality of base cross-sectional areas at the base point of connection.
13 . The dry adhesive fiber structure according to claim 1 , wherein the stem further comprises a surface having a hydrophobic and low surface energy layer on the surface of the stem.
14 . The dry adhesive fiber structure according to claim 1 , wherein the tip and the stem are made of a material selected from the group consisting of liquid polymer and gas phase polymer.
15 . The dry adhesive fiber structure according to claim 12 , wherein the base is made of a material selected from the group consisting of liquid polymer and gas phase polymer.
16 . The dry adhesive fiber structure according to claim 1 ,
wherein the tip further comprises a tip longitudinal axis;
wherein the stem further comprises a stem longitudinal axis; and
wherein the tip longitudinal axis and stem longitudinal axis are coaxial, thereby forming a symmetric orientation between the tip and the stem.
17 . The dry adhesive fiber structure according to claim 12 , further comprising a backing layer connected to the flat surface of the base.
18 . The dry adhesive fiber structure according to claim 1 ,
wherein the plurality of cross sectional areas of the stem further comprises at least two stem cross-sectional areas.
19 . The dry adhesive fiber structure according to claim 1 , further comprising a plurality of second layer fibers connected to the surface of the tip of the dry adhesive fiber.
20 . The dry adhesive fiber structure according to claim 1 , further comprising two or more dry adhesive fibers connected to a backing layer to form a dry adhesive fiber array.
21 . The dry adhesive fiber structure according to claim 20 , further comprising a plurality of second layer fibers connected to at least one dry adhesive fiber of the dry adhesive fiber array.
22 . The dry adhesive fiber structure according to claim 1 , further comprising a second layer fiber connected to the tip of the dry adhesive fiber, wherein the second layer fiber comprises:
a second layer fiber tip having a surface and an end opposite the surface; and
a second layer fiber stem having (i) a distal end connected to the end of the second layer fiber tip at a second layer tip point of connection, and (ii) a proximal end opposite the distal end.
23 . The dry adhesive fiber structure according to claim 22 , wherein the surface of the second layer fiber tip further comprises a flat surface.
24 . The dry adhesive fiber structure according to claim 22 ,
wherein the second layer fiber tip further comprises a plurality of second layer fiber tip cross-sectional areas;
wherein the plurality of second layer fiber tip cross-sectional areas increase from the second layer fiber tip point of connection to the surface of the second layer fiber tip;
wherein the second layer fiber stem further comprises a second layer fiber stem cross-sectional area at the second layer tip point of connection; and
wherein the second layer fiber stem cross-sectional area of the second layer fiber stem at the second layer tip point of connection is equal to or less than a second layer fiber tip cross-sectional area of the plurality of second layer fiber tip cross-sectional areas at the second layer fiber tip point of connection.
25 . The dry adhesive fiber structure according to claim 22 , wherein the surface of the second layer fiber tip comprises a layer of fluorocarbon.
26 . The dry adhesive fiber structure according to claim 22 ,
further comprising a second layer fiber base having a flat surface, an end opposite the flat surface, and a plurality of second layer fiber base cross-sectional areas,
wherein the end of the second layer fiber base is connected to the proximal end of the second layer fiber stem at a second layer fiber base point of connection,
wherein the plurality of second layer fiber base cross-sectional areas increase from the second layer fiber base point of connection to the flat surface of the second layer fiber base,
wherein the second layer fiber stem further comprises a cross-sectional area at the second layer fiber base point of connection, and
wherein the cross-sectional area of the second layer fiber stem at the second layer fiber base point of connection is equal to or less than a second layer fiber base cross-sectional area of the plurality of second layer fiber base cross-sectional areas at the second layer fiber base point of connection.
27 . The dry adhesive fiber structure according to claim 22 , wherein the second layer fiber stem further comprises a surface having a hydrophobic and low surface energy layer on the surface of the second layer fiber stem.
28 . The dry adhesive fiber structure according to claim 22 , wherein the second layer fiber tip and the second layer fiber stem are made of a material selected from the group consisting of liquid polymer and gas phase polymer.
29 . The dry adhesive fiber structure according to claim 26 , wherein the second layer fiber base is made of a material selected from the group consisting of liquid polymer and gas phase polymer.
30 . The dry adhesive fiber structure according to claim 22 ,
wherein the second layer fiber tip further comprises a second layer fiber tip longitudinal axis;
wherein the second layer fiber stem further comprises a second layer fiber stem longitudinal axis; and
wherein the second layer fiber tip longitudinal axis and the second layer fiber stem longitudinal axis are coaxial, thereby forming a symmetric orientation between the second layer fiber tip and the second layer fiber stem.
31 . The dry adhesive fiber structure according to claim 22 ,
wherein the second layer fiber tip further comprises a second layer fiber tip longitudinal axis;
wherein the second layer fiber stem further comprises a second layer fiber stem longitudinal axis; and
wherein the second layer fiber tip longitudinal axis and the second layer fiber stem longitudinal axis are not coaxial, thereby forming an asymmetric orientation between the second layer fiber tip and the second layer fiber stem.
32 . The dry adhesive fiber structure according to claim 22 , wherein the second layer fiber stem further comprises a uniform cross-sectional area along a longitudinal length of the stem.
33 . The dry adhesive fiber structure according to claim 22 , wherein the second layer fiber stem further comprises a non-uniform cross-sectional area along a longitudinal length of the stem.
34 . The dry adhesive fiber structure according to claim 22 ,
wherein the second layer fiber stem further comprises a plurality of second layer fiber stem cross-sectional areas; and
wherein the plurality of second layer fiber stem cross-sectional areas increase from the distal end of the second layer fiber stem to the proximal end of the second layer fiber stem.
35 . The dry adhesive fiber structure according to claim 22 ,
wherein the second layer fiber stem further comprises a plurality of second layer fiber stem cross-sectional areas; and
wherein the plurality of second layer fiber stem cross-sectional areas decrease from the distal end of the stem to the proximal end of the second layer fiber stem.
36 . The dry adhesive fiber structure of claim 1 , further comprising a base having a longitudinal length, wherein the base is connected to the proximal end of the stem.
36 . The dry adhesive fiber structure of claim 1 , further comprising a base having a longitudinal length, wherein the base is connected to the proximal end of the stem.
37 . The dry adhesive fiber structure of claim 1 , further comprising a stem-fiber angle δ that ranges between 1-180 degrees.
38 . The dry adhesive fiber structure of claim 1 , further comprising a tip wedge angle δ that ranges between 1-179 degrees.