Flexible capacitive pressure sensor

• US 10,429,252 B1
• Filed: 08/28/2017
• Issued: 10/01/2019
• Est. Priority Date: 08/26/2016
• Status: Active Grant

• Current Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Original Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Inventors: Squeri, John M., Xu, Minghua
• Primary Examiner(s): Ha, Nguyen Q.
• Application Number:
  US15/688,210
• Time in Patent Office: 764 Days
• CPC Class Codes: G01L 1/144 with associated circuitry G01L1/146 and G01L1/148 take precedence
• CPC Class Codes: G01L 1/146 for measuring force distributions, e.g. using force arrays G01L1/148 takes precedence
• CPC Class Codes: G01L 1/148 using semiconductive material, e.g. silicon
• CPC Class Codes: G01L 5/10 using electrical means
• CPC Class Codes: G01L 9/0005 using variations in capacitance G01L9/0072 takes precedence
• CPC Class Codes: G01L 9/12 by making use of variations in capacitance , i.e. electric circuits therefor
• CPC Class Codes: H01G 13/00 Apparatus specially adapted for manufacturing capacitors; Processes specially adapted for manufacturing capacitors not provided for in groups H01G4/00 - H01G11/00
• CPC Class Codes: H01G 5/0134 Solid dielectrics

Abstract

A flexible passive capacitance pressure sensor includes a first polymeric substrate and a second polymeric substrate. An elastic dielectric sensing material is positioned between the inner-facing surface of the first polymeric substrate and the inner-facing surface of the second polymeric substrate. A first plurality of wires are positioned on the outer-facing surface of said first polymeric substrate, and a second plurality of wires positioned on the outer-facing surface of said second polymeric substrate. The plurality of wires form a flexible capacitor. With the reduced profile enabled by such a capacitor, the flexible passive capacitance pressure sensor can have a thickness of less than 200 microns.

Claims

1. A flexible passive capacitance pressure sensor comprising:

a first polymeric substrate having an inner surface and an outer surface;

a second polymeric substrate having an inner surface and an outer surface;

an elastic dielectric sensing material positioned between the inner surface of the first polymeric substrate and the inner surface of the second polymeric substrate;

a first plurality of wires positioned on the outer surface of the first polymeric substrate; and

a second plurality of wires positioned on the outer surface of the second polymeric substrate,

wherein the flexible passive capacitance pressure sensor has a thickness less than 200 microns.

2. The flexible passive capacitance pressure sensor of claim 1, wherein the first plurality of wires are positioned substantially parallel to each other.

3. The flexible passive capacitance pressure sensor of claim 1, wherein the first plurality of wires are positioned substantially parallel to the second plurality of wires.

4. The flexible passive capacitance pressure sensor of claim 1, wherein the first plurality of wires form a mesh of wires.

5. The flexible passive capacitance pressure sensor of claim 1, wherein the thickness of the flexible passive capacitance pressure sensor is less than 100 microns.

6. The flexible passive capacitance pressure sensor of claim 1, wherein the first and second polymeric substrates are PTFE membranes.

7. The flexible passive capacitance pressure sensor of claim 1, wherein the first and second polymeric substrates are conductive.

8. The flexible passive capacitance pressure sensor of claim 1, wherein the first and second polymeric substrates are non-conductive.

9. A flexible passive capacitance pressure sensor comprising:

a first polymeric substrate having an inner surface and an outer surface;

a second polymeric substrate having an inner surface and an outer surface;

an elastic dielectric sensing material positioned between the first polymeric substrate and the second polymeric substrate on the inner surfaces of the first and second polymeric substrates;

a first metallized film positioned on the outer surface of the first polymeric substrate; and

a second metallized film positioned on the outer surface of the second polymeric substrate,

wherein the flexible passive capacitance pressure sensor has a thickness less than 200 microns.

10. The flexible passive capacitance pressure sensor of claim 9, wherein the first metallized film has thereon a coating comprising a metal.

11. The flexible passive capacitance pressure sensor of claim 9, wherein the first and second polymeric substrates are PTFE membranes.

12. The flexible passive capacitance pressure sensor of claim 9, wherein the first and second polymeric substrates are non-conductive.

13. The flexible passive capacitance pressure sensor of claim 9, wherein the first and second polymeric substrates are conductive.

14. The flexible passive capacitance pressure sensor of claim 9, wherein the thickness of the flexible passive capacitance pressure sensor is less than 100 microns.

15. The flexible passive capacitance pressure sensor of claim 9, wherein the first metallized film is a substrate having thereon a vapor-deposited metal.

16. The flexible passive capacitance pressure sensor of claim 9, wherein the first metallized film is a thin metal foil adhered to a substrate.

17. A flexible passive capacitance pressure sensor comprising:

a first polymeric substrate having an inner surface and an outer surface;

a second polymeric substrate having an inner surface and an outer surface;

an elastic dielectric sensing material positioned between the first polymeric substrate and the second polymeric substrate on the inner surfaces of the first and second polymeric substrates;

a first conductive, filled expanded polytetrafluoroethylene (ePTFE) membrane positioned on the outer surface of the first polymeric substrate; and

a second conductive, filled ePTFE membrane positioned on the outer surface of the second polymeric substrate,

wherein the flexible passive capacitance pressure sensor has a thickness less than 200 microns.

18. The flexible passive capacitance pressure sensor of claim 17, wherein the ePTFE membrane is filled with conductive materials.

19. The flexible passive capacitance pressure sensor of claim 17, wherein the thickness of the flexible passive capacitance pressure sensor is less than 100 microns.

20. The flexible passive capacitance pressure sensor of claim 17, wherein the elastic dielectric sensing material includes silicone, urethane, fluoroelastomers or ePTFE/elastomer combinations.