Nanoparticle-based gas sensors and methods of using the same

Patent metadata

Field	Value
Publication number	US-9791403-B2
Application number	US-201314045711-A
Country	US
Kind code	B2
Filing date	Oct 3, 2013
Priority date	Oct 5, 2012
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

Gas sensors are provided. The gas sensors include a gas sensing element having metal oxide nanoparticles and a thin-film heating element. Systems that include the gas sensors, as well as methods of using the gas sensors, are also provided. Embodiments of the present disclosure find use in a variety of different applications, including detecting whether an analyte is present in a gaseous sample.

First claim

That which is claimed is:

1. A gas sensor comprising:
a gas sensing element comprising metal oxide nanoparticles and a first elongated electrode and a second elongated electrode; and
a substantially linear elongated thin-film heating element;
wherein the first elongated electrode and the second elongated electrode are parallel to the elongated thin-film heating element.

2. The gas sensor of claim 1 , wherein the metal oxide nanoparticles are disposed between the first elongated electrode and the second elongated electrode.

3. The gas sensor of claim 1 , wherein the metal oxide nanoparticles comprise tungsten oxide nanoparticles and the gas sensor is configured to detect hydrogen sulfide.

4. The gas sensor of claim 3 , wherein the metal oxide nanoparticles have an average diameter of 100 nm or less.

5. The gas sensor of claim 1 , wherein the thin-film heating element comprises polysilicon.

6. The gas sensor of claim 1 , further comprising an insulation layer between the gas sensing element and the thin-film heating element.

7. The gas sensor of claim 6 , wherein the insulation layer comprises silicon nitride.

8. The gas sensor of claim 1 , wherein the gas sensor is configured to have a thermal efficiency ranging from 30° C./mW to 200° C./mW.

9. The gas sensor of claim 1 , wherein the gas sensor is configured to have a limit of detection of 1 ppm or less.

10. The gas sensor of claim 1 , wherein the metal oxide nanoparticles comprise groupings of the metal oxide nanoparticles that do not substantially contact surrounding groupings of the metal oxide nanoparticles but are interconnected by one or more bridges of the metal oxide nanoparticles.

11. A gas sensor system comprising:
one or more gas sensors, wherein each gas sensor comprises:
a gas sensing element comprising metal oxide nanoparticles and a first elongated electrode and a second elongated electrode; and
a substantially linear elongated thin-film heating element;
wherein the first elongated electrode and the second elongated electrode are parallel to the elongated thin-film element.

12. The gas sensor system of claim 11 , wherein the gas sensor system comprises an array of gas sensors.

13. The gas sensor system of claim 12 , wherein the array comprises 6 or more gas sensors.

14. The gas sensor system of claim 12 , wherein the array has a length of 3 mm or less and a width of 3 mm or less.

15. The gas sensor system of claim 11 , further comprising a controller configured to repeatedly activate and deactivate the thin-film heating element over a period of time.

16. The gas sensor system of claim 15 , wherein the controller is configured to activate the thin-film heating element with a duty cycle of 20% or less.

17. The gas sensor system of claim 15 , wherein the controller is configured to activate the thin-film heating element with a frequency of 0.1 Hz or more.

18. A method of detecting whether an analyte is present in a gaseous sample, the method comprising:
contacting a gaseous sample to a gas sensor to produce a signal, the gas sensor comprising:
a gas sensing element comprising metal oxide nanoparticles and a first elongated electrode and a second elongated electrode; and
a substantially linear elongated thin-film heating element;
wherein the first elongated electrode and the second elongated electrode are parallel to the elongated thin-film element; and

analyzing the signal to determine whether the analyte is present in the gaseous sample.

19. The method of claim 18 , further comprising heating the gas sensing element with the thin-film heating element during the contacting.

20. The method of claim 19 , wherein the heating comprises repeatedly activating and deactivating the thin-film heating element over a period of time.

21. The method of claim 18 , further comprising determining the concentration of the analyte in the gaseous sample based on the signal.

22. The method of claim 21 , further comprising activating an alarm if the concentration of the analyte is greater than a threshold value.

Assignees

• Univ California

Inventors

• Mickelson William
• Zettl Alex

Classifications

• G01N27/127

  comprising nanoparticles · CPC title

• G01N27/403 Primary

  Cells and electrode assemblies · CPC title

• G01N33/0044 Primary

  Sulphides, e.g. H2S · CPC title