Improved reversible adhesives and methods of forming the same

Patent metadata

Field	Value
Publication number	US-2016167331-A1
Application number	US-201414909477-A
Country	US
Kind code	A1
Filing date	Aug 1, 2014
Priority date	Aug 2, 2013
Publication date	Jun 16, 2016
Grant date	—

Abstract

Provided herein are adhesion systems comprising a first substrate at least a portion of the surface of which having an array of micropillars, at least a distal portion of said micropillars having a plurality of particles embedded therein, and a second substrate at least a portion of the surface of which having an array of micropillars, at least a distal portion of said micropillars having a plurality of particles embedded therein. Adhesive materials comprising a substrate at least a portion of the surface of which having an array of micropillars, at least a portion of said micropillars having a plurality of particles embedded therein, and methods of forming the same, are also disclosed.

First claim

1 . An adhesion system comprising:
a first substrate at least a portion of the surface of which having an array of micropillars, at least a distal portion of said micropillars having a plurality of particles embedded therein; and a second substrate at least a portion of the surface of which having an array of micropillars, at least a distal portion of said micropillars having a plurality of particles embedded therein.

2 . The adhesion system of claim 1 , wherein said plurality of particles are embedded substantially on a distal end of the micropillars.

3 . The adhesion system of claim 1 , wherein said plurality of particles are embedded throughout said micropillars.

4 . The adhesion system of claim 1 , wherein said micropillars are comprised of an elastomer.

5 . The adhesion system of claim 4 , wherein said elastomer is a polyurethane acrylate (PUA).

6 . The adhesion system of claim 1 , wherein said plurality of particles comprises a single particle type.

7 . The adhesion system of claim 1 , wherein said plurality of particles comprises silica.

8 . The adhesion system of claim 1 , wherein the plurality of particles have a diameter of about 20 nm to about 10 μm.

9 . The adhesion system of claim 1 , said micropillars having a diameter of about 100 nm to about 50 μm.

10 . The adhesion system of claim 1 , wherein said array of micropillars is selected to conform to a geometric pattern.

11 . The adhesion system of claim 1 , said array of micropillars having a height of about 1 μm to about 500 μm.

12 . The adhesion system of claim 1 , wherein the plurality of particles embedded on a distal end of the micropillars have a thickness from about 1% to about 50% of the height of the micropillars.

13 . The adhesion system of claim 1 , said array of micropillars having an aspect ratio of about 2 to about 10.

14 . The adhesion system of claim 1 , said array of micropillars having a spacing ratio of about 2 to about 6.

15 . The adhesion system of claim 1 , wherein said substrates are arranged such that the array of micropillars from said first substrate are capable of interacting with the array of micropillars from said second substrate.

16 . The adhesion system of claim 15 , wherein said array of micropillars from the first substrate and said array of micropillars from the second substrate are capable of interlocking.

17 . The adhesion system of claim 16 , wherein said interlocking comprises interdigitation, interweaving, indentation, or any combination thereof.

18 . The adhesion system of claim 1 , wherein a strength of interaction between the array of micropillars from the first substrate and the array of micropillars from the second substrate is greater than an interaction between pristine micropillars.

19 . The adhesion system of claim 18 , wherein the strength of interaction is at least 4 to 5 times greater than an interaction between pristine micropillars.

20 . The adhesion system of claim 1 , wherein said interaction between the micropillars of the first substrate and the micropillars of the second substrate is reversible.

21 . The adhesion system of claim 1 , wherein said system is reusable.

22 . The adhesion system of claim 1 , optionally comprising one or more additional substrates at least a portion of the surface of which having an array of micropillars, at least a portion of said micropillars having a plurality of particles embedded therein.

23 . An adhesive material comprising:
a substrate at least a portion of the surface of which having an array of micropillars, at least a portion of said micropillars having a plurality of particles embedded therein.

24 . The adhesive material of claim 23 , wherein said plurality of particles are embedded substantially on a distal end of the micropillars.

25 . The adhesive material of claim 23 , wherein said plurality of particles are embedded randomly on said micropillars.

26 . The adhesive material of claim 23 , wherein said micropillars are composed of an elastomer.

27 . The adhesive material of claim 26 , wherein said elastomer is polyurethane acrylate (PUA).

28 . The adhesive material of claim 23 , wherein said plurality of particles comprises a single particle type.

29 . The adhesive material of claim 23 , wherein said plurality of particles comprises silica.

30 . The adhesive material of claim 23 , wherein the plurality of particles have a diameter of about 20 nm to about 10 μm.

31 . The adhesive material of claim 23 , said micropillars having a diameter of about 100 nm to about 50 μm.

32 . The adhesive material of claim 23 , wherein said array of micropillars is selected to conform to a geometric pattern.

33 . The adhesive material of claim 23 , said array of micropillars having a height of about 1 μm to about 500 μm.

34 . The adhesive material of claim 23 , said array of micropillars having an aspect ratio of about 2 to about 10.

35 . The adhesive material of claim 23 , said array of micropillars having a spacing ratio of about 2 to about 6.

36 . A method of forming the adhesive material of claim 23 comprising:
drop-casting a particle suspension over a mold, wherein the particle suspension contains a solvent and a plurality of particles;
removing excess solvent from the mold;
removing excess particles;
filling the mold with one or more elastomers;
polymerizing the elastomers;
and removing the adhesive material from the mold.

37 . The method of claim 36 , wherein the mold comprises PDMS.

38 . The method of claim 36 , wherein the plurality of particles comprise silica.

39 . The method of claim 36 , wherein the excess solvent is removed by blading.

40 . The method of claim 36 , wherein the elastomer is UV-curable PUA.

41 . The method of claim 36 , wherein the elastomers are polymerized by photopolymerization with UV light.

Assignees

• Univ Pennsylvania

Inventors

• Yang Shu
• Rahmawan Yudi
• Shu Kahp-Yang

Classifications

• B32B27/20

  using fillers, pigments, thixotroping agents · CPC title

• B29K2105/251

  Particles, powder or granules (expandable particles B29K2105/046) · CPC title

• B32B2250/02

  2 layers · CPC title

• B29C39/025

  for making multilayered articles · CPC title

• B29L2031/756

  Microarticles, nanoarticles · CPC title