Carbon nanotube sensor

• US 7,057,402 B2
• Filed: 01/10/2005
• Issued: 06/06/2006
• Est. Priority Date: 03/18/2002
• Status: Expired due to Term

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Cole, Barrett E., Zook, David J.
• Primary Examiner(s): Deb, Anjan
• Assistant Examiner(s): Teresinski, John
• Application Number:
  US11/032,470
• Publication Number:
  US 20050134296A1
• Time in Patent Office: 512 Days
• Field of Search: 324/464, 324/715
• US Class Current: 324/715
• 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: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: G01J 5/02 Constructional details
• CPC Class Codes: G01J 5/023 Particular leg structure or construction or shape; Nanotubes
• CPC Class Codes: G01J 5/024 Special manufacturing steps or sacrificial layers or layer structures
• CPC Class Codes: G01J 5/08 Optical arrangements
• CPC Class Codes: G01J 5/0853 having infrared absorbers other than the usual absorber layers deposited on infrared detectors like bolometers, wherein the heat propagation between the absorber and the detecting element occurs within a solid
• CPC Class Codes: G01N 33/0027 concerning the detector
• CPC Class Codes: Y10S 977/955 Of thermal property
• CPC Class Codes: Y10T 436/235 In an aqueous solution [e.g., TOC, etc.]

Abstract

Carbon nanotubes are formed on projections on a substrate. A metal, such as nickel is deposited on the substrate with optional platforms, and heated to form the projections. Carbon nanotubes are formed from the projections by heating in an ethylene, methane or CO atmosphere. A heat sensor is also formed proximate the carbon nanotubes. When exposed to IR radiation, the heat sensor detects changes in temperature representative of the IR radiation. In a gas sensor, a thermally isolated area, such as a pixel is formed on a substrate with an integrated heater. A pair of conductors each have a portion adjacent a portion of the other conductor with projections formed on the adjacent portions of the conductors. Multiple carbon nanotubes are formed between the conductors from one projection to another. IV characteristics of the nanotubes are measured between the conductors in the presence of a gas to be detected.

Claims

1. A sensor comprising:

a thermally isolated area on a substrate;

a heating element proximate the thermally isolated area;

a pair of conductors each having a portion adjacent a portion of the other; and

a plurality of carbon nanotubes formed extending from one of the conductors to the other.

2. The sensor of claim 1 wherein the carbon nanotubes comprise single wall carbon nanotubes.

3. The sensor of claim 1 wherein the heating element is formed in a substrate beneath the pair of conductors.

4. The sensor of claim 1 wherein the heating element substantially laterally surrounds the pair of conductors.

5. The sensor of claim 1 wherein the heating element is formed proximate the conductors such that it provides heat to form the nanotubes, or to remove gas adsorbed by the nanotubes.

6. The sensor of claim 1 wherein the heating element is integrated with the thermally isolated area.

7. A sensor comprising:

a thermally isolated area on a substrate;

a heating element proximate the thermally isolated area;

a pair of conductors each having a portion adjacent a portion of the other;

projections formed on the adjacent portions of the conductors; and

a carbon nanotube formed extending between the conductors from one projection to another.

8. The sensor of claim 7 wherein the projections are formed of nickel.

9. The sensor of claim 7 wherein the projections are formed of cobalt.

10. The sensor of claim 7 wherein the carbon nanotubes comprise single wall carbon nanotubes.

11. The sensor of claim 7 and further comprising circuitry formed on the substrate.

12. The sensor of claim 11 wherein the circuitry is coupled to the two conductors for measuring the IV characteristics of the nanotubes in the presence of gas.

13. The sensor of claim 7 wherein the heating element is formed proximate the conductors such that it provides heat to form the nanotubes, or to remove gas adsorbed by the nanotubes.

14. The sensor of claim 7 wherein the heating element is integrated with the thermally isolated area.

15. A sensor comprising:

a thermally isolated pixel on a substrate;

a heating element proximate the pixel;

a pair of conductors each having a portion adjacent a portion of the other;

a plurality of projections formed on each of the adjacent portions of the conductors; and

a plurality of carbon nanotubes formed from projections on one conductor to projections on the other conductor.

16. A sensor comprising:

a thermally isolated pixel on a substrate;

a heating element proximate the pixel;

a pair of conductors each having a portion adjacent a portion of the other;

a plurality fingers extending from each of the conductors, wherein the fingers are meshed adjacent to each other such that fingers alternate between conductors;

a plurality of projections formed on each of the fingers of the conductors; and

a plurality of carbon nanotubes formed from projections on each finger on conductor to an adjacent finger on a different conductor.

17. The sensor of claim 16 wherein the heating element is formed in a substrate beneath the pair of conductors.

18. The sensor of claim 16 wherein the heating element substantially laterally surrounds the pair of conductors.

19. The sensor of claim 16 wherein the heating element is formed proximate the conductors such that it provides heat to form the nanotubes, or to remove gas adsorbed by the nanotubes.

20. The sensor of claim 16 wherein the heating element is integrated with the thermally isolated area.