Com/iphone method of making superoleophobic re-entrant resist structures

Abstract

A device and method for preparing a device having a superoleophobic surface are disclosed. The method includes providing a substrate; coating a lift-off resist layer on the substrate; baking the lift-off resist layer; layering a photoresist layer on the lift-off resist layer; performing photolithography to create a textured pattern in the photoresist layer and the lift-off resist layer, and chemically modifying the textured pattern to create a superoleophobic surface.

What is claimed is: 
     
         1 . A front face for an ink jet printhead, the front face comprising:
 a flexible substrate, wherein the flexible substrate comprises
 a plastic film; 
 a lift-off resist layer; 
 a photoresist layer,
 wherein the lift-off resist layer and the photoresist layer form a textured pattern, 
 wherein the textured pattern comprises at least one overhang re-entrant structure; and 
 a conformal fluoropolymer or fluorosilane coating disposed on a surface of the textured pattern. 
 
   
     
     
         2 . The front face according to  claim 1 , wherein the conformal coating is selected from the group consisting of fluorosilane layers synthesized from tridecafluoro-1,1,2,2-tetrahydrooctyltrichlorosilane, tridecafluoro-1,1,2,2-tetrahydrooctyltrimethoxysilane, tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane, heptadecafluoro-1,1,2,2-tetrahydrooctyltrichlorosilane, heptadecafluoro-1,1,2,2-tetrahydrooctyltrimethoxysilane, and heptadecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane, a perfluoropolyether polymer and an amorphous fluoropolymer copolymerized from tetrafluoroethylene and 2,2-bis-trifluoromethyl-4,5-difluoro-1,3-dioxole, or combinations thereof. 
     
     
         3 . The front face according to  claim 1 , wherein the lift-off resist layer comprises poly(methyl methacrylate). 
     
     
         4 . The front face according to  claim 1 , wherein the lift-off resist layer comprises polymethylglutarimide. 
     
     
         5 . The front face according to  claim 1 , wherein the textured pattern has a solid area coverage of about 0.5% to about 80% of the substrate. 
     
     
         6 . The front face according to  claim 1 , wherein the texture pattern comprises overhang re-entrant structures, wherein the overhang re-entrant structures have height of about 0.1 microns to about 10 microns. 
     
     
         7 . The front face according to  claim 1 , wherein the texture pattern comprises overhang re-entrant structures, wherein the overhang re-entrant structures have a thickness of about 0.1 microns to about 10 microns. 
     
     
         8 . The front face according to  claim 1 , wherein the textured pattern is an overhang re-entrant structure with an undercut of about 0.1 microns to about 5 microns. 
     
     
         9 . The front face according to  claim 1 , wherein the overhang re-entrant structure is an individual re-entrant structure or a continuous grooved structure. 
     
     
         10 . The front face according to  claim 9 , wherein the individual re-entrant structures are spaced from about 0.5 μm to about 10 μm apart when measured from the centers of the individual re-entrant structures. 
     
     
         11 . The front face according to  claim 9 , wherein the continuous groove structures have a length of at least about 3 times of the width. 
     
     
         12 . The front face according to  claim 1 , wherein the lift-off resist layer has a thickness of from about 0.1 microns to about 10 microns. 
     
     
         13 . The front face according to  claim 1 , wherein a static contact angle for hexadecane on the conformal coating is 151. 
     
     
         14 . A front face for an ink jet printhead, the front face comprising:
 a flexible substrate, wherein the flexible substrate comprises
 a plastic film; 
 a lift-off resist layer; 
 a photoresist layer,
 wherein the lift-off resist layer and the photoresist layer form a textured pattern, 
 wherein the textured pattern comprises at least one overhang re-entrant structure; and 
 a conformal fluoropolymer or fluorosilane coating disposed on a surface of the textured pattern, wherein a hydrocarbon-based ink forms a contact-angle with a surface of the conformal coating disposed on the surface of the textured pattern that is greater than about 150°. 
 
   
     
     
         15 . A flexible device comprising a flexible substrate having a superoleophobic surface, wherein the flexible substrate comprises
 a plastic film;   a lift-off resist layer;   a photoresist layer,
 wherein the lift-off resist layer and the photoresist layer form a textured pattern, 
 wherein the textured pattern comprises at least one overhang re-entrant structure; and 
 a conformal fluoropolymer or fluorosilane coating disposed on a surface of the textured pattern, wherein the conformal coating disposed on the surface of the textured pattern comprises a superoleophobic surface. 
   
     
     
         16 . The flexible device according to  claim 15 , wherein the conformal coating is selected from the group consisting of fluorosilane layers synthesized from tridecafluoro-1,1,2,2-tetrahydrooctyltrichlorosilane, tridecafluoro-1,1,2,2-tetrahydrooctyltrimethoxysilane, tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane, heptadecafluoro-1,1,2,2-tetrahydrooctyltrichlorosilane, heptadecafluoro-1,1,2,2-tetrahydrooctyltrimethoxysilane, and heptadecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane, a perfluoropolyether polymer and an amorphous fluoropolymer copolymerized from tetrafluoroethylene and 2,2-bis-trifluoromethyl-4,5-difluoro-1,3-dioxole, or combinations thereof. 
     
     
         17 . The flexible device according to  claim 15 , wherein the lift-off resist layer is a poly(methyl methacrylate) or a polymethylglutarimide layer. 
     
     
         18 . The front face according to  claim 15 , wherein the textured pattern has a solid area coverage of about 0.5% to about 80% of the substrate. 
     
     
         19 . The front face according to  claim 15 , wherein the conformal coating comprises a copolymer that is copolymerized from tetrafluoroethylene (TFE) and 2,2-bis-trifluoromethyl-4,5-difluoro-1,3-dioxole (BDD) monomers. 
     
     
         20 . The front face according to  claim 15 , wherein the overhang re-entrant structure is an individual re-entrant structure or a continuous grooved structure.