Flexible capacitive pressure sensor
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.
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.