IP Library › Granted Patent US 12,658,344
Granted Patent B2
US 12,658,344 · App. 18/014,244 · Granted Jun 16, 2026

Copper-ANF composite conductor fabrication

Inventors: Mark Hammig (Dexter, MI); Nicholas Kotov (Ann Arbor, MI); Jing Lyu (Beijing, CN); Suneel Joglekar (West Lafayette, IN)
Assignee: The Regents of the University of Michigan
H01B13/30H01B1/22
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Quick Facts
Patent No.
US 12,658,344
App. No.
18/014,244
Granted
Jun 16, 2026
Kind
B2
Abstract

A method of fabricating a conductor includes preparing an aramid nanofiber solution in which a matrix of aramid nanofibers is dispersed, preparing a dispersion of copper nanoparticles, each copper nanoparticle of the dispersion of cooper nanoparticles having an organic capping ligand attached to the copper nanoparticle, and incorporating copper nanoparticles of the dispersion of copper nanoparticles into the matrix of aramid nanofibers such that each incorporated copper nanoparticle is bonded to a respective aramid nanofiber of the matrix of aramid nanofibers via the organic capping ligand to which the copper nanoparticle is attached. The organic capping ligand may include a mercaptocarboxyiic acid.

Claims (62)

1 . A method of fabricating a conductor, the method comprising:

preparing an aramid nanofiber solution in which a matrix of aramid nanofibers is dispersed;

preparing a dispersion of copper nanoparticles, each copper nanoparticle of the dispersion of cooper nanoparticles having an organic capping ligand attached to the copper nanoparticle; and

incorporating copper nanoparticles of the dispersion of copper nanoparticles into the matrix of aramid nanofibers such that each incorporated copper nanoparticle is bonded to a respective aramid nanofiber of the matrix of aramid nanofibers via the organic capping ligand to which the copper nanoparticle is attached;

wherein the organic capping ligand comprises a mercaptocarboxylic acid.

2 . The method of claim 1 , wherein the mercaptocarboxylic acid comprises mercaptosuccinic acid.

3 . The method of claim 1 , wherein preparing the dispersion of copper nanoparticles comprises lowering a pH of the dispersion in preparation for incorporating the plurality of copper nanoparticles into the matrix of aramid nanofibers.

4 . The method of claim 3 , wherein the pH is lowered to between about 7 and about 8.

5 . The method of claim 1 , further comprising:

coating a substrate with the aramid fiber solution using a spin coating process; and

implementing a vacuum filtration procedure in which the film is disposed as a filtration membrane.

6 . The method of claim 1 , further comprising:

coating a substrate with the aramid fiber solution using a blade to form a film; and

implementing a vacuum filtration procedure in which the film is disposed as a filtration membrane.

7 . The method of claim 6 , further comprising forming a conductive structure from the film after incorporating the copper nanoparticles, wherein forming the conductive structure comprises drawing the film onto a spool.

8 . The method of claim 1 , wherein incorporating the copper nanoparticles comprises:

releasing the aramid fiber solution as a stream in a hydrolyzing solution to form a wire; and

soaking the wire in the dispersion of copper nanoparticles.

9 . The method of claim 1 , wherein incorporating the copper nanoparticles comprises:

injecting the dispersion of copper nanoparticles into a stream of the aramid nanofiber solution provided by a first needle such that a composite stream is defined by the first needle; and

injecting the composite stream into a stream of a hydrolyzing solution to define a thread in the hydrolyzing solution.

10 . The method of claim 9 , further comprising forming a conductive wire from the defined thread after incorporating the copper nanoparticles, wherein forming the conductive wire comprises drawing the conductive wire onto a spool.

11 . The method of claim 1 , wherein preparing the dispersion of copper nanoparticles comprises curing the dispersion of copper nanoparticles after the nanoparticle growth.

12 . The method of claim 1 , wherein preparing the dispersion of copper nanoparticles comprises lowering a pH of the dispersion after growth of the copper nanoparticles.

13 . A method of fabricating a conductor, the method comprising:

preparing an aramid nanofiber solution in which a matrix of aramid nanofibers is dispersed;

preparing a dispersion of copper nanoparticles, each copper nanoparticle of the dispersion of cooper nanoparticles having an organic capping ligand attached to the copper nanoparticle; and

incorporating copper nanoparticles of the dispersion of copper nanoparticles into the matrix of aramid nanofibers such that each incorporated copper nanoparticle is bonded to a respective aramid nanofiber of the matrix of aramid nanofibers via the organic capping ligand to which the copper nanoparticle is attached;

wherein preparing the dispersion of copper nanoparticles comprises:

establishing a first pH for the dispersion during nanoparticle growth; and

adjusting the dispersion from the first pH to a second pH after the nanoparticle growth in preparation for incorporating the plurality of copper nanoparticles into the matrix of aramid nanofibers, the second pH being lower than the first pH.

14 . The method of claim 13 , further comprising:

coating a substrate with the aramid fiber solution using a blade to form a film; and

implementing a vacuum filtration procedure in which the film is disposed as a filtration membrane.

15 . The method of claim 14 , further comprising forming a conductive structure from the film after incorporating the copper nanoparticles, wherein forming the conductive structure comprises drawing the film onto a spool.

16 . The method of claim 13 , further comprising:

coating a substrate with the aramid fiber solution using a spin coating process; and

implementing a vacuum filtration procedure in which the film is disposed as a filtration membrane.

17 . The method of claim 13 , wherein incorporating the copper nanoparticles comprises:

releasing the aramid fiber solution as a stream in a hydrolyzing solution to form a wire; and

soaking the wire in the dispersion of copper nanoparticles.

18 . The method of claim 13 , wherein incorporating the copper nanoparticles comprises:

injecting the dispersion of copper nanoparticles into a stream of the aramid nanofiber solution provided by a first needle such that a composite stream is defined by the first needle; and

injecting the composite stream into a stream of a hydrolyzing solution to define a thread in the hydrolyzing solution.

19 . The method of claim 18 , further comprising forming a conductive wire from the defined thread after incorporating the copper nanoparticles, wherein forming the conductive wire comprises drawing the conductive wire onto a spool.

20 . The method of claim 13 , wherein preparing the dispersion of copper nanoparticles comprises curing the dispersion of copper nanoparticles after the nanoparticle growth.

21 . The method of claim 20 , wherein curing the dispersion of copper nanoparticles is implemented after adjusting the dispersion to the second pH.

22 . The method of claim 13 , wherein the second pH is between about 7 and about 8.

23 . The method of claim 13 , wherein the organic capping ligand comprises a mercaptocarboxylic acid.

24 . The method of claim 22 , wherein the mercaptocarboxylic acid comprises mercaptosuccinic acid.

25 . The method of claim 13 , wherein the organic capping ligand comprises a thiol group and a carboxyl group.

26 . The method of claim 13 , wherein the organic capping ligand comprises a hydroxyl group, carboxyl group, an amine group, a thiol group, or any combination thereof.

27 . A method of fabricating a conductive wire, the method comprising:

preparing an aramid nanofiber solution in which a matrix of aramid nanofibers are dispersed;

preparing a dispersion of copper nanoparticles, each copper nanoparticle of the dispersion of copper nanoparticles having an organic capping ligand attached to the copper nanoparticle;

injecting the dispersion of copper nanoparticles into a stream of the aramid nanofiber solution to form a composite stream in which copper nanoparticles of the dispersion of metal nanoparticles are incorporated into the matrix of aramid nanofibers such that each incorporated copper nanoparticle is bonded to a respective aramid nanofiber of the matrix of aramid nanofibers via the organic capping ligand to which the copper nanoparticle is attached;

releasing the composite stream into a hydrolyzing solution to form a composite structure; and

forming the conductive wire from the composite structure.

28 . The method of claim 27 , wherein releasing the composite stream comprises injecting the composite stream into a stream of the hydrolyzing solution.

29 . The method of claim 27 , wherein the hydrolyzing solution comprises a further dispersion of copper nanoparticles.

30 . The method of claim 29 , wherein the further dispersion of copper nanoparticles is diluted relative to the prepared dispersion of copper nanoparticles.

31 . The method of claim 27 , wherein forming the conductive wire comprises drawing the conductive wire onto a spool.

Assignments (2)
CONFIRMATORY LICENSE Recorded Mar 27, 2026
From: MICHIGAN, UNIVERSITY OF
To: DEFENSE THREAT REDUCTION AGENCY
Reel/Frame 075289/0194 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 19, 2026
From: HAMMIG, MARK; KOTOV, NICHOLAS; LYU, JING; JOGLEKAR, SUNEEL
To: THE REGENTS OF THE UNIVERSITY OF MICHIGAN
Reel/Frame 073830/0569 →
Continuity (2)
Provisional Application 63046920 · Jul 1, 2020
Related Publication 20230260680A1 · Aug 17, 2023
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