Direct metal printing with stereolithography
View Patent ↗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.
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.