Direct metal printing with stereolithography

Abstract

An additive manufacturing process for forming a metallic layer on the surface of the substrate includes fabricating a substrate from a polymerizable composition by a stereolithographic process, and contacting the reactive surface with an aqueous solution including a metal precursor. The metal precursor includes a metal, and the polymerizable composition includes a multiplicity of multifunctional components. Each multifunctional component includes a reactive moiety extending from a surface of the substrate to form a reactive surface. An interface between the reactive surface and the aqueous solution is selectively irradiated to form nanoparticles including the metal in a desired pattern. The nanoparticles are chemically coupled to the reactive surface by reactive moieties, thereby forming a metallic layer on the surface of the substrate.

What is claimed is: 
     
         1 . A method of additive manufacturing, the method comprising:
 fabricating a substrate in a first printing step from a polymerizable composition by a stereolithographic process, wherein the polymerizable composition comprises a multiplicity of multifunctional components, each multifunctional component comprising a reactive moiety, and each reactive moiety extends from a surface of the substrate to form a reactive surface; wherein
 the multifunctional component comprises allylamine; and 
 the reactive moiety comprises amine; 
   contacting the reactive surface with an aqueous solution comprising a metal precursor, wherein the metal precursor comprises a metal;   selectively irradiating an interface between the reactive surface and the aqueous solution in a desired pattern during a second printing step to form nanoparticles comprising the metal in the desired pattern; and   chemically coupling the nanoparticles to the reactive surface by the reactive moieties, thereby forming a metallic layer comprising the metal on the surface of the substrate.   
     
     
         2 . The method of  claim 1 , wherein the polymerizable composition comprises an acrylate monomer. 
     
     
         3 . The method of  claim 2 , wherein the acrylate monomer comprises a diacrylate monomer. 
     
     
         4 . The method of  claim 3 , wherein the diacrylate monomer comprises 1,6-hexanediol diacrylate. 
     
     
         5 . The method of  claim 1 , wherein the polymerizable composition comprises a photoinitiator. 
     
     
         6 . The method of  claim 5 , wherein the photoinitiator comprises phenylbis(2,4,6-trimethylbenzoyl) phosphine oxide. 
     
     
         7 . The method of  claim 1 , wherein the metal is a transition metal. 
     
     
         8 . The method of  claim 7 , wherein the metal is silver. 
     
     
         9 . The method of  claim 1 , wherein the aqueous solution further comprises a chelating agent. 
     
     
         10 . The method of  claim 9 , wherein the chelating agent comprises citrate. 
     
     
         11 . The method of  claim 1 , further comprising forming an additional metallic layer on the surface. 
     
     
         12 . The method of  claim 1 , wherein a conductance of the metallic layer is the same order of magnitude as a conductance of the metal in bulk form. 
     
     
         13 . The method of  claim 1 , wherein the metallic layer forms a continuous film on the substrate. 
     
     
         14 . The method of  claim 13 , wherein the continuous film comprises a multiplicity of nanoparticles, nanoparticle aggregates, or both. 
     
     
         15 . The method of  claim 14 , wherein a dimension of the continuous film exceeds a dimension of the nanoparticles by at least a factor of 1000. 
     
     
         16 . The method of  claim 14 , wherein a dimension of the metallic layer is at least 1 cm. 
     
     
         17 . The method of  claim 1 , wherein a resolution of the metallic layer is up to 10 μm. 
     
     
         18 . The method of  claim 1 , wherein the metallic layer is formed under ambient conditions. 
     
     
         19 . The method of  claim 1 , wherein the substrate is an organic polymer or a hydrogel. 
     
     
         20 . The method of  claim 1 , further comprising photoreducing the aqueous solution comprising a metal precursor with continuous irradiation to form the nanoparticles.