Sensing physical attributes

1. An apparatus for sensing a physical attribute, comprising:

a first track defining a first electrode on a substrate;

a second track defining a second electrode on said substrate; and

an active film comprising a variable resistance material in cooperation with a first sensor portion of said first electrode and a second sensor portion of said second electrode, wherein:

said second electrode includes a first extended portion to establish a first additional resistance not cooperating with said active film; and

said first sensor portion, said second sensor portion and said first extended portion comprise the same conductive material.

2. The apparatus of claim 1 , wherein said first additional resistance is configured to provide a reference resistor.

3. The apparatus of claim 2 , wherein said reference resistor is configured to provide a measurable voltage when said second electrode is conducting current.

4. The apparatus of claim 1 , wherein said first sensor portion is interdigitated with said second sensor portion.

5. The apparatus of claim 4 , wherein said extended portion surrounds said interdigitated first sensor portion and said second sensor portion.

6. The apparatus of claim 4 , further comprising a second extended portion and a third extended portion, wherein said interdigitated portions defining a variable resistance are combined with said first additional resistance, a second additional resistance defined by said second extended portion and a third additional resistance defined by said third extended portion in a bridge configuration.

7. The apparatus of claim 1 , wherein said physical attribute is applied force.

8. The apparatus of claim 1 , wherein said attribute is applied pressure.

9. The apparatus of claim 1 , wherein said first extended portion is configured to facilitate compensation against fluctuations in an ambient condition.

10. The apparatus of claim 9 , wherein said ambient condition is temperature.

11. A method of constructing an apparatus for sensing a physical attribute, comprising the steps of:

defining a first electrode on a substrate;

further defining a second electrode on said substrate;

arranging an active film comprising a variable resistance material to cooperate with a first sensor portion of said first electrode and a second sensor portion of said second electrode; and

establishing a first additional resistance in an extended portion of said first electrode;

wherein said first sensor portion, said second sensor portion and said first extended portion comprise the same conductive material.

12. The method of claim 11 , further comprising the step of configuring said first additional resistance to provide a reference resistor.

13. The method of claim 12 , further comprising the step of further configuring said reference resistor to provide a measurable voltage when said second electrode is conducting current.

14. The method of claim 11 , further comprising the step of interdigitating first elements of said first electrode with second elements of said second electrode.

15. The method of claim 14 , further comprising the step of surrounding said first elements and said second elements with said extended portion.

16. A method of sensing a physical attribute, comprising the steps of:

exposing a sensor portion of cooperating electrodes to said physical attribute, in which variable current flows through said cooperating electrodes; and

measuring a voltage with respect to a reference resistance,

wherein said reference resistance is established as a first additional resistance in one of said cooperating electrodes, said sensor portion and said first additional resistance comprise the same conductive material.

17. The method of claim 16 , wherein said physical attribute is force.

18. The method of claim 16 , wherein said physical attribute is pressure.

19. The method of claim 17 wherein force or pressure is applied as a result of a manual interaction.

20. The method of claim 19 , wherein said manual interaction involves an application of a user's finger.