Method and apparatus for enhancing detection characteristics of a chemical sensor system

• US 20100001211A1
• Filed: 07/01/2008
• Published: 01/07/2010
• Est. Priority Date: 07/01/2008
• Status: Abandoned Application

• Current Assignee: Smiths Detection (Smiths Group International Holdings Ltd.)
• Original Assignee: Smiths Detection (Smiths Group International Holdings Ltd.)
• Inventors: Fabrizio, Eve F., Huang, Weijie, Burch, Timothy E.
• Application Number:
  US12/216,223
• Publication Number:
  US 20100001211A1
• Time in Patent Office: Days
• US Class Current: 250/492.1
• 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: G01N 27/4141 specially adapted for gases
• CPC Class Codes: G01N 27/4146 involving nanosized elements, e.g. nanotubes, nanowires
• CPC Class Codes: G01N 33/0029 cleaning
• CPC Class Codes: G01N 33/0057 for warfare agents or explosives properties of explosives G01N33/227

Abstract

A method and apparatus for increasing detection characteristics of a chemical sensor array that has been previously exposed to an agent in order to detect and categorize the agent. Ultraviolet light at a predetermined wavelength is applied to the chemical sensor array, in order to desorb the agent from the chemical sensor array, so as to increase a resistance of the chemical sensor array. Alternatively or together with the ultraviolet light, a bias voltage is applied to at least one biasing electrode making up the chemical sensor array, in order to desorb the agent from the chemical sensor array, so as to increase the resistance of the chemical sensor array. The chemical sensor array may be a carbon nanotube sensor array.

Claims

1. A method for improving detection characteristics of a chemical sensor array that has been previously exposed to an agent in order to detect and categorize the agent, the method comprising:

applying ultraviolet light at a predetermined wavelength to the chemical sensor array, in order to desorb the agent from the chemical sensor array, so as to return a resistance, conductance and/or capacitance of the chemical sensor array back to its original value.

2. The method according to claim 1, further comprising the step of:

applying heat to the chemical sensor array, in order to desorb the agent from the chemical sensor array, so as to return the resistance, conductance, and/or capacitance of the chemical sensor array back to its original value.

3. The method according to claim 1, wherein the chemical sensor array includes at least one biasing electrode, the method further comprising the step of:

applying a voltage to the at least one biasing electrode, in order to desorb the agent from the chemical sensor array, so as to return the resistance, conductance, and/or capacitance of the chemical sensor array back to its original value.

4. The method according to claim 3, wherein the chemical sensor array comprises a carbon nanotube sensor array that is either pristine or chemically-modified sensors, or both.

5. The method according to claim 3, wherein the applying step is performed periodically at predetermined intervals.

6. The method according to claim 2, wherein the chemical sensor array includes at least one biasing electrode, the method further comprising the step of:

applying a bias voltage to the at least one biasing electrode, in order to desorb the agent from the chemical sensor array, so as to return the resistance, conductance, and/or capacitance of the chemical sensor array back to its original value.

7. A method for improving detection characteristics of a chemical sensor array that has been previously exposed to an agent in order to detect and categorize the agent, wherein the chemical sensor array includes at least one biasing electrode, the method further comprising the step of:

applying a bias voltage to the at least one biasing electrode, in order to desorb the agent from the chemical sensor array, so as to return a resistance, conductance and/or capacitance of the chemical sensor array back to its original value.

8. The method according to claim 7, further comprising the step of:

applying ultraviolet light at a predetermined wavelength to the chemical sensor array, in order to desorb the agent from the chemical sensor array, so as to return a resistance, conductance and/or capacitance of the chemical sensor array back to its original value.

9. The method according to claim 7, further comprising the step of:

applying heat to the chemical sensor array, in order to desorb the agent from the chemical sensor array, so as to return the resistance, conductance and/or capacitance of the chemical sensor array back to its original value.

10. The method according to claim 7, wherein the chemical sensor array comprises a carbon nanotube sensor array that includes either pristine or chemically-modified sensors, or both.

11. The method according to claim 7, wherein the applying step is performed periodically at predetermined intervals.

12. An apparatus for improving detection characteristics of a chemical sensor array that has been previously exposed to an agent in order to detect and categorize the agent, the apparatus comprising:

an ultraviolet light emitting unit that emits ultraviolet light at a predetermined wavelength to the chemical sensor array, in order to desorb the agent from the chemical sensor array, so as to return a resistance, conductance and/or capacitance of the chemical sensor array back to its original value.

13. The apparatus according to claim 12, wherein the ultraviolet light emitting unit includes at least one light emitting diode.

14. The apparatus according to claim 12, wherein the chemical sensor array includes at least one biasing electrode, the apparatus further comprising:

a bias voltage applying unit configured to applying a bias voltage to the at least one biasing electrode, in order to desorb the agent from the chemical sensor array, so as to return the resistance, conductance and/or capacitance of the chemical sensor array back to its original value.

15. The apparatus according to claim 12, further comprising:

a heating unit configured to apply heat to the chemical sensor array, in order to desorb the agent from the chemical sensor array, so as to return the resistance, conductance and/or capacitance of the chemical sensor array back to its original value.

16. The apparatus according to claim 12, wherein the chemical sensor array comprises a carbon nanotube sensor array.

17. The apparatus according to claim 14, wherein the bias voltage applying unit applies the bias voltage periodically at predetermined intervals to the chemical sensor array.

18. A computer readable medium embodying computer program product for improving sensor response characteristics, the computer program product, when executed by a computer or a microprocessor, causing the computer or the microprocessor to perform the steps of:

providing control signals to a light applying unit so as to apply ultraviolet light at a predetermined wavelength to a chemical sensor array, in order to desorb the agent from the chemical sensor array, so as to return a resistance, conductance and/or capacitance of the chemical sensor array back to its original value.

19. The computer readable medium according to claim 18, wherein the light applying unit corresponds to at least one LED.

20. The computer readable medium according to claim 18, wherein the chemical sensor array is a carbon nanotube sensor array that includes either pristine or chemically-modified sensors, or both.

21. A computer readable medium embodying computer program product for improving sensor response characteristics, the computer program product, when executed by a computer or a microprocessor, causing the computer or the microprocessor to perform the steps of applying a bias voltage to at least one biasing electrode of a chemical sensor array, in order to desorb the agent from the chemical sensor array, so as to return a resistance, conductance and/or capacitance of the chemical sensor array back to its original value.

22. The computer readable medium according to claim 21, wherein the chemical sensor array is a carbon nanotube sensor array that includes either pristine or chemically-modified sensors, or both.

23. The computer readable medium according to claim 21, wherein the sensor array is a carbon black or carbon black filled polymer composite sensor array.