Conductive and stretchable polymer composite

• US 10,390,698 B2
• Filed: 06/16/2017
• Issued: 08/27/2019
• Est. Priority Date: 06/16/2016
• Status: Active Grant

• Current Assignee: Arizona Board of Regents (University of Arizona)
• Original Assignee: Arizona Board of Regents (University of Arizona)
• Inventors: Yu, Hongbin, Vanjaria, Jignesh, Houghton, Todd
• Primary Examiner(s): Kopec, Mark
• Assistant Examiner(s): Thomas, Jaison P
• Application Number:
  US15/625,893
• Publication Number:
  US 20170362423A1
• Time in Patent Office: 802 Days
• CPC Class Codes: A61B 2562/0261 Strain gauges
• CPC Class Codes: A61B 2562/12 Manufacturing methods specially adapted for producing sensors for in-vivo measurements
• CPC Class Codes: A61B 5/00 Measuring for diagnostic purposes radiation diagnosis A61B6/00; diagnosis by ultrasonic, sonic or infrasonic waves A61B8/00; Identification of persons
• CPC Class Codes: C08G 2261/1424 containing ether groups, including alkoxy
• CPC Class Codes: C08G 2261/3223 containing one or more sulfur atoms as the only heteroatom, e.g. thiophene
• CPC Class Codes: C08G 2261/51 Charge transport
• CPC Class Codes: C08G 2261/62 Mechanical aspects
• CPC Class Codes: C08G 2261/794 with polymeric dopants
• CPC Class Codes: C08G 2261/94 Applications in sensors, e.g. biosensors
• CPC Class Codes: C08J 2329/04 Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
• CPC Class Codes: C08J 2425/18 Homopolymers or copolymers of aromatic monomers containing elements other than carbon and hydrogen
• CPC Class Codes: C08J 2465/00 Characterised by the use of macromolecular compounds obtained by reactions forming a carbon-to-carbon link in the main chain C08J2407/00 - C08J2457/00, C08J2461/00 take precedence; Derivatives of such polymers
• CPC Class Codes: C08J 3/21 the polymer being premixed with a liquid phase
• CPC Class Codes: C08K 3/08 Metals
• CPC Class Codes: C08L 2205/03 containing three or more polymers in a blend
• CPC Class Codes: C08L 25/18 Homopolymers or copolymers of aromatic monomers containing elements other than carbon and hydrogen
• CPC Class Codes: C08L 29/04 Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
• CPC Class Codes: C08L 65/00 Compositions of macromolecular compounds obtained by reactions forming a carbon-to-carbon link in the main chain C08L7/00 - C08L57/00, C08L61/00 take precedence; Compositions of derivatives of such polymers
• CPC Class Codes: H01B 1/14 Conductive material dispersed in non-conductive inorganic material

Abstract

Disclosed herein is a composite prepared by dispersing silver flakes in a polyvinyl alcohol (PVA), phosphoric acid (H₃PO₄), and poly(3,4-ethyl-ene-dioxythiophene) (PEDOT):poly(styrene sulfonic acid) (PSS) polymer mixture. The polymer blend can provides conductive pathways between the silver flakes, leading to superior electrical properties even at large deformations.

Claims

1. A composite comprising:

a conductive polymer;

a water-soluble polymer;

a plasticizer; and

metal flakes, wherein the metal flakes have a diameter of about 1 μ

m to about 45 μ

m, and

wherein the plasticizer is phosphoric acid.

2. The composite of claim 1, wherein the conductive polymer is selected from the group consisting of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate), polyacetylene, and polyphenylene vinylene.

3. The composite of claim 2, wherein the conductive polymer is poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate).

4. The composite of claim 3, wherein the poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) includes poly(styrenesulfonate) and poly(3,4-ethylenedioxythiophene) in a weight ratio of about 1.0 to about 5.0.

5. The composite of claim 1, wherein the water-soluble polymer is selected from the group consisting of polyvinyl alcohol, polyethylene glycol, and polyvinylpyrrolidone.

6. The composite of claim 5, wherein the water-soluble polymer is polyvinyl alcohol.

7. The composite of claim 6, wherein the polyvinyl alcohol has a molecular weight of about 145 kDa to about 200 kDa.

8. The composite of claim 1, wherein the metal flakes comprise silver, copper, gold, platinum, zinc, or a mixture of any thereof.

9. The composite of claim 8, wherein the metal flakes are silver metal flakes.

10. A method of preparing a composite according to claim 1, comprising:

dissolving the water-soluble polymer in water to form a first solution;

adding the plasticizer to the first solution to form a second solution;

adding a solution or suspension of the conductive polymer to the second solution to form a polymer blend; and

adding the metal flakes to the polymer blend to form the composite.

11. The method of claim 10, further comprising drop casting and drying the composite.

12. A capacitive strain gauge comprising the composite according to claim 1.

13. The capacitive strain gauge according to claim 12, wherein the composite inhabits trenches in a silicone rubber substrate.

14. The capacitive strain gauge according to claim 13, wherein the substrate is about 3 mm thick and the trench is about 1.5 mm deep.

15. The capacitive strain gauge according to claim 12, wherein the gauge is an interdigitated capacitive strain gauge.

16. A method of preparing the capacitive strain gauge according to claim 12, comprising:

providing a sheet of silicone rubber;

laser cutting a trench into the silicone rubber sheet, wherein the trench is cut in an interdigitated configuration; and

dispensing the composite into the trench.

17. A method of preparing a composite, the method comprising:

providing a composite comprising

a conductive polymer;

a water-soluble polymer;

a plasticizer; and

metal flakes, wherein the metal flakes have a diameter of about 1 μ

m to about 45 μ

m dissolving the water-soluble polymer in water to form a first solution;

adding the plasticizer to the first solution to form a second solution;

adding a solution or suspension of the conductive polymer to the second solution to form a polymer blend; and

adding the metal flakes to the polymer blend to form the composite.

18. The method of claim 17, further comprising drop casting and drying the composite.

19. A capacitive strain gauge comprising:

a composite comprising

a conductive polymer;

a water-soluble polymer;

a plasticizer; and

metal flakes, wherein the metal flakes have a diameter of about 1 μ

m to about 45 μ

m wherein the composite inhabits trenches in a silicone rubber substrate.

20. The capacitive strain gauge according to claim 19, wherein the gauge is an interdigitated capacitive strain gauge.