Metal-containing photopolymer resins generated by reduction of dissolved metal salts

1. A three-dimensional structure, comprising:

at least one crosslinked photopolymer in a metallized first portion of the structure and a non-metallized second portion of the structure,

wherein the structure is characterized by:

having at least one metal dispersed throughout the metallized first portion of the structure and a salt of the metal in the non-metallized second portion of the structure; and

comprising features having a horizontal and/or vertical feature resolution in a range from several hundred nanometers to several hundred microns.

2. The structure as recited in claim 1 , wherein the metal comprises gold.

3. The structure as recited in claim 1 , wherein the structure comprises a plurality of layers of the at least one crosslinked photopolymer, each layer having a thickness in a range from about 10 nm to about 500 μm.

4. The structure as recited in claim 1 , wherein the metallized first portion of the structure throughout which the metal is dispersed comprises a continuous pathway defining a circuit, wherein the continuous pathway is conductive.

5. A method for forming a three-dimensional structure, the method comprising:

curing a first photopolymeric resin using projection microstereolithography (PμSL) for forming a first section of a three-dimensional structure, the first section having solely polymer;

dissolving at least one metal salt in a second resin comprising one or more photopolymers;

curing portions of the second resin using projection microstereolithography (PμSL) to form a second section of the three-dimensional structure on the first section, the second section having therein the at least one metal salt; and

reducing metal ions within the three-dimensional structure to form the three-dimensional metallized structure, wherein metal is dispersed throughout a bulk of the second section of the three-dimensional structure.

6. The method as recited in claim 5 , wherein the reducing comprises chemical reduction.

7. A method for forming a three-dimensional structure having at least one metal plated thereon, the method comprising:

dissolving at least one metal salt in a resin comprising one or more photopolymers and a hydrogel ink;

curing portions of the resin to form the three-dimensional structure; and

electroless plating at least one metal directly onto surfaces of the three-dimensional structure.

8. The method as recited in claim 7 , wherein the one or more photopolymers comprise at least one photopolymer selected from the group consisting of: hexane diol diacrylate (HDDA); polyethylene glycol diacrylate (PEGDA); ethylene glycol dimethacrylate (EGDMA); thiol-ene; and silicones.

9. The method as recited in claim 7 , comprising utilizing metal ions incorporated in the surfaces of the three-dimensional structure as catalysts for the electroless plating.

10. The method as recited in claim 7 , further comprising etching away polymeric regions of the three-dimensional structure to form a hollow metal part.

11. A method for forming a selectively metallized three-dimensional structure, the method comprising:

dissolving at least one metal salt in a resin comprising one or more photopolymers;

curing first portions of the resin by exposing the first portions of the resin to a first profile of light to form non-metallized, crosslinked portions of a three-dimensional structure; and

selectively reducing metal ions in second portions of the resin by exposing the metal ions and the second portions of the resin to a second profile of light to form metallized, crosslinked portions of the three-dimensional structure.

12. The method as recited in claim 11 , comprising iteratively repeating the curing and the selectively reducing, wherein each iteration forms a layer of the three-dimensional structure.

13. The method as recited in claim 11 , wherein curing the portions of the resin comprises exposing the portions of the resin to light having a wavelength corresponding to an active wavelength of a photoinitiator in the resin; and

wherein the portions of the resin are defined according to a first digital mask, the first digital mask comprising an array of micromirrors and/or a liquid crystal on silicon (LCoS) device.

14. The method as recited in claim 11 , comprising selectively preventing reduction of metal ions solvated in the resin by mixing a photoactive reduction inhibitor into the resin.

15. The method as recited in claim 14 , wherein the photoactive reduction inhibitor comprises o-nitrophenyl-egtazic acid (o-nitrophenyl-EGTA).

16. The method as recited in claim 11 , wherein the first profile of light comprises first light having a wavelength that causes the one or more photopolymers to crosslink upon exposure thereto; and wherein the second profile of light comprises:

the first light; and

second light having a wavelength that causes the metal ions to reduce into metal upon exposure thereto.

17. The method as recited in claim 11 , wherein the resin further comprises a hydrogel ink.

18. The method as recited in claim 11 , wherein the curing and the selectively reducing are performed in a single exposure.