Three-dimensional printed porous silicone matrix using leachable porogen

Abstract

The silicone-based ink for additive manufacturing includes a siloxane macromer, and a porogen mixture comprising a water-soluble porogen and a surfactant. The product of additive manufacturing with a silicone-based ink includes a three-dimensional printed structure including a plurality of continuous filaments arranged in a predefined pattern and a plurality of inter-filament pores defined by the predefined pattern of the continuous filaments. In addition, each continuous filament of the three-dimensional printed structure includes a silicone matrix having an open cell structure with a plurality of intra-filament pores, and the intra-filament pores form continuous channels through the silicone matrix.

What is claimed is: 
     
         1 . A silicone-based ink for additive manufacturing, the ink comprising:
 a siloxane macromer; and   a porogen mixture comprising a water-soluble porogen and a surfactant.   
     
     
         2 . The ink as recited in  claim 1 , wherein the siloxane macromer includes a vinyl-terminated siloxane macromer. 
     
     
         3 . The ink as recited in  claim 1 , wherein the water-soluble porogen includes glycerol. 
     
     
         4 . The ink as recited in  claim 3 , wherein a concentration of the glycerol is in a range of about 35 weight% to about 50 weight% of a total weight of the ink. 
     
     
         5 . The ink as recited in  claim 1 , wherein the surfactant includes polyvinyl pyrrolidone. 
     
     
         6 . The ink as recited in  claim 5 , where in a concentration of the polyvinyl pyrrolidone is in a range of greater than 0 wt% to about 25 weight% of a total weight of the ink. 
     
     
         7 . The ink as recited in  claim 1 , further comprising a curing agent. 
     
     
         8 . The ink as recited in  claim 1 , comprising an untreated silica. 
     
     
         9 . The ink as recited in  claim 1 , comprising a rheology modifying additive. 
     
     
         10 . The ink as recited in  claim 1 , wherein the porogen mixture further comprises a plurality of porogen particles. 
     
     
         11 . The ink as recited in  claim 10 , wherein the porogen particles are selected from the group consisting of: urea particles, sugar particles, polyethylene glycol, and a combination thereof. 
     
     
         12 . The ink as recited in  claim 1 , wherein a concentration of the siloxane macromer is in a range of about 25 weight% to about 70 weight% of a total weight of ink. 
     
     
         13 . A product of additive manufacturing with a silicone-based ink, the product comprising:
 a three-dimensional printed structure comprising:
 a plurality of continuous filaments arranged in a predefined pattern, the continuous filaments each comprising a silicone matrix having an open cell structure with a plurality of intra-filament pores, wherein the intra-filament pores form continuous channels through the silicone matrix; and 
 a plurality of inter-filament pores, wherein the inter-filament pores are defined by the predefined pattern of the continuous filaments. 
   
     
     
         14 . The product as recited in  claim 13 , wherein the silicone matrix includes vinyl terminated siloxane polymers. 
     
     
         15 . The product as recited in  claim 13 , wherein the continuous filaments have an average diameter greater than about 100 microns. 
     
     
         16 . The product as recited in  claim 13 , wherein the inter-filament pores are interconnected from a surface of the three-dimensional printed structure to a surface on an opposite side of the three-dimensional printed structure.