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

Patent metadata

Field	Value
Publication number	US-10563308-B2
Application number	US-201615208494-A
Country	US
Kind code	B2
Filing date	Jul 12, 2016
Priority date	Jul 12, 2016
Publication date	Feb 18, 2020
Grant date	Feb 18, 2020

Abstract

According to one embodiment, a three-dimensional structure includes: at least one photopolymer having at least one metal dispersed throughout at least portions of a bulk of the structure. The structure is characterized by features having a horizontal and/or vertical feature resolution in a range from several hundred nanometers to several hundred microns. The portions of the bulk throughout which metal is dispersed may optionally be selectively determined. In more embodiments, the structure may have electroless plated metal formed on surfaces thereof, alternatively or in addition to the metal dispersed throughout the bulk of the structure. The electroless plating may be achieved without the use of a surface activation bath. Corresponding methods for forming various embodiments of such three dimensional structures are also disclosed.

First claim

What is claimed is:

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.

Assignees

• L Livermore Nat Security Llc
• Lawrence Livermore Nat Security

Inventors

• Golobic Alexandra
• Duoss Eric
• Jackson Julie A
• Pascall Andrew

Classifications

• C23C18/32

  Coating with nickel, cobalt or mixtures thereof with phosphorus or boron (C23C18/50 takes precedence) · CPC title

• C23C18/1612

  through irradiation means · CPC title

• C23C18/31 Primary

  Coating with metals · CPC title

• C23C18/1608

  from pretreatment step, i.e. selective pre-treatment · CPC title

• C08K2003/0806

  Silver · CPC title