Force responsive inductors for force sensors

1. An inductor comprising:

an inductor layer;

a reference layer comprising an electrically conductive material, the electrically conductive material being geometrically patterned such that the reference layer includes three or more electrically isolated conductive regions; and

a variable layer formed between the reference layer and inductor layer, wherein a thickness of the variable layer is configured to change upon application of a force external to the variable layer thereby causing a change in position of the reference layer relative the inductor layer, and wherein the change in position of the reference layer relative the inductor layer changes an inductance of the inductor.

2. The inductor of claim 1 , wherein the electrically conductive material comprises electrically conductive particles dispersed within a polymer.

3. The inductor of claim 2 , wherein the polymer comprises a polymeric film, foam, or elastomer.

4. The inductor of claim 1 , wherein the variable layer comprises a compressible layer, and wherein the thickness of the compressible layer is configured to decrease upon application of the force external to the compressible layer causing the inductance of the inductor to increase.

5. The inductor of claim 1 , wherein the variable layer comprises polymeric foam or an elastomeric layer.

6. The inductor of claim 1 , wherein the variable layer is directly adjacent to the reference layer and the inductor layer.

7. The inductor of claim 1 , wherein the inductor layer is configured as an antenna element.

8. The inductor of claim 1 , further comprising:

an input connection to the inductor layer; and

an output connection to the inductor layer, wherein the input connection and the output connection are configured to allow the inductor to be connected to a circuit.

9. A sensor comprising the inductor of claim 1 ,

wherein the sensor is configured to detect the force based on the change in inductance of the inductor.

10. The sensor of claim 9 , wherein the electrically conductive material comprises electrically conductive particles dispersed within a polymer.

11. The sensor of claim 9 , wherein the variable layer comprises a compressible layer, and wherein the thickness of the compressible layer is configured to decrease upon application of the force external to the compressible layer causing the inductance of the inductor to increase.

12. An article comprising the sensor of claim 9 .

13. The article of claim 12 , wherein the article comprises one of a compression bandage, a compression sleeve, or a compression stocking.

14. The article of claim 12 , wherein the electrically conductive material comprises electrically conductive particles dispersed within a polymer.

15. The article of claim 14 , wherein the polymer comprises a polymeric film, foam, or elastomer.

16. The article of claim 12 , wherein the variable layer comprises a compressible layer, and wherein the thickness of the compressible layer is configured to decrease upon application of the force external to the compressible layer causing the inductance of the inductor to increase.

17. The article of claim 12 , wherein the variable layer comprises polymeric foam or an elastomeric layer.

18. The article of claim 12 , further comprising a circuit, wherein the circuit comprises:

an input connection to the inductor layer; and

an output connection to the inductor layer, wherein the input connection and the output connection are configured to allow the inductor to be connected to the circuit.

19. A system comprising:

the inductor of claim 1 ; and

a circuit coupled to the inductor element via the input and output connectors.