Sensor and a method of making a sensor

• US 8,020,456 B2
• Filed: 05/26/2009
• Issued: 09/20/2011
• Est. Priority Date: 05/30/2008
• Status: Expired due to Fees

• Current Assignee: Florida State University (State University System of Florida)
• Original Assignee: Florida State University (State University System of Florida)
• Inventors: Liu, Tao, Liang, Zhiyong, Wang, Ben, Zhang, Chun
• Primary Examiner(s): PERT, EVAN T
• Application Number:
  US12/471,903
• Publication Number:
  US 20090309172A1
• Time in Patent Office: 847 Days
• Field of Search: 738/626.21, 738/626.25, 738/626.28, 738/626.32, 738/626.37
• US Class Current: 73/862.621
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: G01L 1/205 using distributed sensing elements

Abstract

A sensor is provided, which includes a plurality of conducting elements spaced apart from each other and at least one deformable electrolyte bridge contacting each of the conducting elements at one or more contact points having an aggregate contact area. Upon formation of an ionic circuit between two of the conducting elements, a first resistivity between the two conducting element exists. Upon application of a compressive force on the at least one deformable electrolyte bridge directed toward at least one of the conducting elements, the aggregate contact area increases such that a second resistivity between the two conducting elements exists.

Claims

1. A thin film sensor for measuring pressure or mechanical displacement comprising:

a first substrate having a load receiving side and an opposed conducting element side;

a plurality of conducting elements located on the first substrate at the conducting element side in positions spaced apart from one another;

a deformable second substrate located on the conducting element side of the first substrate; and

at least one deformable electrolyte bridge located on the deformable second substrate and contacting each of the conducting elements at one or more contact points, said contact points having an aggregate contact area,

wherein, upon formation of an ionic circuit between two of the conducting elements, a first resistivity exists between said two conducting elements when the first substrate is in an unloaded state at a location at or about said two conducting elements, and a second resistivity exists between said two conducting elements when the first substrate is in a loaded state at said location and the at least one deformable electrolyte bridge is deformed at or about said location in an amount to increase the aggregate contact area.

2. The sensor of claim 1, further comprising means for forming an ionic circuit between two of the conducting elements.

3. The sensor of claim 1, wherein the conducting elements are elongated and parallel to one another.

4. The sensor of claim 1, wherein the conducting elements comprise nanoscale fibers.

5. The sensor of claim 1, wherein the conducting elements comprise nanoscale fiber films.

6. The sensor of claim 1, wherein the at least one deformable electrolyte bridge is elastically deformable.

7. The sensor of claim 1, wherein the first substrate comprises a polymer and the conducting elements comprise metalized structures disposed on the first substrate.

17. The sensor of claim 1, further comprising a deformable material adjacent to the conducting elements, the at least one deformable electrolyte bridge, or both.

8. A thin film sensor comprising:

a plurality of conducting elements spaced apart from each other; and

at least one deformable electrolyte bridge contacting each of the conducting elements at one or more contact points having an aggregate contact area such that upon formation of an ionic circuit between two of the conducting elements, a first resistivity between the two conducting element exists, and upon application of a compressive force on the at least one deformable electrolyte bridge directed toward at least one of the conducting elements, the aggregate contact area increases such that a second resistivity between the two conducting elements exists.

9. The sensor of claim 8, further comprising means for forming an ionic circuit between two of the conducting elements.

10. The sensor of claim 8, wherein the conducting elements comprise nanoscale fibers.

11. The sensor of claim 8, wherein the conducting elements comprise nanoscale fiber films.

12. The sensor of claim 8, wherein the at least one deformable electrolyte bridge is elastically deformable.

13. The sensor of claim 8, wherein the at least one deformable electrolyte bridge comprises an arched surface having arch ends contacting each of the conducting elements such that an upper portion of the arched surface is spaced apart from the conducting elements, and wherein upon application of the compressive force, the upper portion of the arched surface contacts at least one of the conducting elements.

14. The sensor of claim 8, wherein the conducting elements comprise a plurality of conducting element strips positioned parallel to each other, and wherein the at least one deformable electrolyte bridge comprises a plurality of deformable electrolyte bridges positioned parallel to each other and traverse to the conducting element strips.

15. The sensor of claim 8, further comprising a substrate adjacent to the conducting elements, wherein the substrate is spaced apart from the at least one deformable electrolyte bridge.

16. The sensor of claim 14, wherein the substrate comprises a polymer and the conducting elements comprise metalized structures disposed on the substrate.

18. The sensor of claim 16, wherein the at least one deformable electrolyte bridge comprises a polyacrylate salt.

19. A method for making a sensor comprising:

disposing a plurality of conducting elements at positions spaced apart from each other; and

disposing at least one deformable electrolyte bridge onto the conducting elements at one or more contact points having an aggregate contact area such that upon formation of an ionic circuit between two of the conducting elements, a first resistivity between the two conducting element exists, and upon application of a compressive force on the at least one deformable electrolyte bridge directed toward at least one of the conducting elements, the aggregate contact area increases such that a second resistivity between the two conducting elements exists.

20. The method of claim 19, wherein the conducting elements comprise nanoscale fibers or nanoscale fiber films.

21. The method of claim 19, wherein the conducting elements are provided by cutting and removing the conducting elements from a conducting material with a patterned stamp.

22. The method of claim 19, further comprising disposing a deformable material on the conducting elements, the electrolyte bridges, or both.

23. The method of claim 22, wherein the steps of disposing the at least one deformable electrolyte bridge and disposing the deformable material comprise providing a deformable material including grooves, disposing a plurality of deformable electrolyte bridges in the grooves, and disposing the deformable material with the deformable electrolyte bridges in the grooves onto the conducting elements.

24. A method of sensing a pressure differential comprising:

locating a sensor at a site where it is desired to sense a pressure change, the sensor comprising a plurality of conducting elements spaced apart from each other and at least one deformable electrolyte bridge contacting each of the conducting elements at one or more contact points having an aggregate contact area;

forming of an ionic circuit between two of the conducting elements;

measuring a first resistivity between the two conducting elements;

upon application of a compressive force on the at least one deformable electrolyte bridge directed toward at least one of the conducting elements to cause a change in the aggregate contact area, measuring a second resistivity between the two conducting elements; and

comparing the first and second resistivity to identify a pressure or pressure change at the site.