Method of minimizing residue adhesion for thermo-reversible dry adhesives

Abstract

One embodiment of the invention includes a method of joining two substrates with multilayer thermo-reversible dry adhesives and separating the two bonded substrates by completely thermally reversing the adhesion via heating.

1 . A product comprising:
 a multilayer thermo-reversible dry adhesive comprising:   a first layer comprising a dry adhesive and a non-adhesive portion; and   a second layer comprising a shape memory polymer.   
     
     
         2 . A product as set forth in  claim 1  further comprising a substrate, wherein the first layer is positioned over the substrate. 
     
     
         3 . A product as set forth in  claim 2  wherein the adhesive strength between the multilayer thermo-reversible dry adhesive and the substrate is about 1-200 N/cm 2 . 
     
     
         4 . A product as set forth in  claim 1  wherein the non-adhesive portion comprises at least one of glass, metal, or polytetrafluoroethylene. 
     
     
         5 . A product as set forth in  claim 1  wherein the non-adhesive portion is positioned on the side of the first layer that is not in contact with the second layer. 
     
     
         6 . A product as set forth in  claim 5  wherein the non-adhesive portion is positioned in approximately the center of the first layer. 
     
     
         7 . A product as set forth in  claim 1  wherein the non-adhesive portion is provided by an opening or recess in the first layer. 
     
     
         8 . A product as set forth in  claim 1  wherein the dry adhesive comprises:
 at least one of a rigid epoxy or a flexible epoxy; and 
 at least one of a crosslinking agent or a catalytic curing agent; 
 wherein the rigid epoxy is an aromatic epoxy having at least two epoxide groups, the flexible epoxy is an aliphatic epoxy having at least two epoxide groups, and the crosslinking agent is one of a multi-amine, an organic multi-carboxylic acid, or an anhydride. 
 
     
     
         9 . A product as set forth in  claim 1  wherein the shape memory polymer comprises:
 at least one of a rigid epoxy or a flexible epoxy; and 
 at least one of a crosslinking agent or a catalytic curing agent; 
 wherein the rigid epoxy is an aromatic epoxy having at least two epoxide groups, the flexible epoxy is an aliphatic epoxy having at least two epoxide groups, and the crosslinking agent is one of a multi-amine, an organic multi-carboxylic acid, or an anhydride. 
 
     
     
         10 . A product as set forth in  claim 1  wherein the multilayer thermo-reversible dry adhesive has a first shape at a first temperature and a second shape at a second temperature with a load applied. 
     
     
         11 . A product as set forth in  claim 1  further comprising a third layer comprising an elastomeric dry adhesive and a fourth layer comprising a shape memory polymer. 
     
     
         12 . A product as set forth in  claim 11  wherein the third layer further comprises a non-adhesive portion. 
     
     
         13 . A product as set forth in  claim 11  wherein the first layer overlies the second layer and the third layer overlies the fourth layer, and further comprising a cavity in between the second layer and the fourth layer. 
     
     
         14 - 20 . (canceled)