Metal-metal composite ink and methods for forming conductive patterns
A printed stretchable strain sensor is provided. The printed stretchable strain sensor has a stretchable substrate and a composite ink coupled to a surface of the stretchable substrate to form a strain-sensitive conductive structure. The composite ink includes both a nanowire and a metal flake. The capability of the fabricated strain sensor, printed in two design configurations: straight line and wavy line, was investigated by studying its electro-mechanical response towards varying elongations of 1 mm, 2 mm, and 3 mm.
1. A printed stretchable strain sensor comprising:
a stretchable substrate; and
a composite ink coupled to a surface of the stretchable substrate to form a strain-sensitive conductive structure;
wherein the composite ink comprises a nanowire and a metal flake,
wherein the nanowire is present in the metal flake at a nanowire weight percent of from about 0.1% to about 10.0%, and
wherein the composite ink is substantially free of triblock copolymeric materials.
2. The printed stretchable strain sensor of claim 1 , wherein the nanowire comprises silver nanowire, gold nanowire, copper nanowire, nickel nanowire, carbon nanowire, platinum nanowire, aluminum nanowire, or combinations thereof.
3. The printed stretchable strain sensor of claim 1 , wherein the metal flake comprises silver flake, gold flake, copper flake, nickel flake, platinum flake, aluminum flake, or combinations thereof.
4. The printed stretchable strain sensor of claim 1 , wherein the printed stretchable strain sensor has a maximum strain of up to 50%.
5. The printed stretchable strain sensor of claim 1 , wherein the stretchable substrate comprises silicone, polyurethane, polybutadiene, neoprene, polydimethylsiloxane, silicone rubbers, or combinations thereof.
6. The printed stretchable strain sensor of claim 1 , wherein the composite ink coupled to the surface of the stretchable substrate to form the strain-sensitive conductive structure is a straight line configuration.
7. The printed stretchable strain sensor of claim 6 , wherein the straight line configuration has a sensitivity of about 20.0% to 25.0% in resistance change for every 1% strain.
8. The printed stretchable strain sensor of claim 1 , wherein the composite ink coupled to the surface of the stretchable substrate to form the strain-sensitive conductive structure is a wavy line configuration.
9. The printed stretchable strain sensor of claim 8 , wherein the wavy line configuration has a sensitivity of about 30.0% to 35.0% in resistance change for every 1% strain.
10. A method of printing a stretchable strain sensor, the method comprising:
mixing a nanowire together with a metal flake to form a composite ink, wherein the nanowire is present in the metal flake at a nanowire weight percent of from about 0.1% to about 10.0%, and wherein the composite ink is substantially free of triblock copolymeric materials;
depositing the composite ink in a predetermined continuous configuration onto a surface of a stretchable substrate; and
curing the composite ink to form a strain-sensitive conductive structure.
11. The method of claim 10 , wherein the nanowire comprises silver nanowire, gold nanowire, copper nanowire, nickel nanowire, carbon nanowire, platinum nanowire, aluminum nanowire, or combinations thereof.
12. The method of claim 10 , wherein the metal flake comprises silver flake, gold flake, copper flake, nickel flake, platinum flake, aluminum flake, or combinations thereof.
13. The method of claim 10 , wherein the printed stretchable strain sensor has a maximum strain of up to 50%.
14. The method of claim 10 , wherein the stretchable substrate comprises silicone, polyurethane, polybutadiene, neoprene, polydimethylsiloxane, silicone rubbers, or combinations thereof.
15. The method of claim 10 , wherein the composite ink coupled to the surface of the stretchable substrate to form the strain-sensitive conductive structure is a straight line configuration.
16. The method of claim 15 , wherein the straight line configuration has a sensitivity of about 20.0% to 25.0% in resistance change for every 1% strain.
17. The method of claim 10 , wherein the composite ink coupled to the surface of the stretchable substrate to form the strain-sensitive conductive structure is a wavy line configuration.
18. The method of claim 17 , wherein the wavy line configuration has a sensitivity of about 30.0% to 35.0% in resistance change for every 1% strain.
19. The printed stretchable strain sensor of claim 1 , wherein the nanowire present in the metal flake is selected from:
silver nanowire present in silver metal flake;
gold nanowire present in gold metal flake;
copper nanowire present in copper metal flake;
nickel nanowire present in nickel metal flake;
platinum nanowire present in platinum metal flake; and
aluminum nanowire present in aluminum metal flake.
20. The method of claim 10 , wherein the mixing a nanowire together with a metal flake comprises one of:
mixing a silver nanowire together with a silver metal flake;
mixing a gold nanowire together with a gold metal flake;
mixing a copper nanowire together with a copper metal flake;
mixing a nickel nanowire together with a nickel metal flake;
mixing a platinum nanowire together with a platinum metal flake; and
mixing an aluminum nanowire together with an aluminum metal flake.