Nanoparticle-Based Gas Sensors and Methods of Using the Same

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.

1 . A gas sensor comprising:
 a gas sensing element comprising metal oxide nanoparticles;   a thin-film heating element; and   a membrane comprising an insulation material, wherein the insulation material is between the membrane and the thin-film heating element.   
     
     
         2 . The gas sensor of  claim 1 , wherein the gas sensing element comprises a first electrode and a second electrode with the metal oxide nanoparticles disposed between the first electrode and the second 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 . A gas sensor system comprising:
 one or more gas sensors, wherein each gas sensor comprises:
 gas sensing element comprising metal oxide nanoparticles; 
 a thin-film heating element; and 
 a membrane comprising an insulation material, wherein the insulation material is between the membrane and the thin-film heating element. 
   
     
     
         11 . The gas sensor system of  claim 10 , wherein the gas sensor system comprises an array of 6 or more gas sensors. 
     
     
         12 . (canceled) 
     
     
         13 . The gas sensor system of  claim 11 , wherein the array has a length of 3 mm or less and a width of 3 mm or less. 
     
     
         14 . The gas sensor system of  claim 10 , further comprising a controller configured to repeatedly activate and deactivate the thin-film heating element over a period of time. 
     
     
         15 . The gas sensor system of  claim 14 , wherein the controller is configured to activate the thin-film heating element with a duty cycle of 20% or less. 
     
     
         16 . The gas sensor system of  claim 14 , wherein the controller is configured to activate the thin-film heating element with a frequency of 0.1 Hz or more. 
     
     
         17 . 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; 
 a thin-film heating element; and 
 a membrane comprising an insulation material, wherein the insulation material is between the membrane and the thin-film heating element; and 
   analyzing the signal to determine whether the analyte is present in the gaseous sample.   
     
     
         18 . The method of  claim 17 , further comprising heating the gas sensing element with the thin-film heating element during the contacting. 
     
     
         19 . The method of  claim 18 , wherein the heating comprises repeatedly activating and deactivating the thin-film heating element over a period of time. 
     
     
         20 . The method of  claim 17 , further comprising determining the concentration of the analyte in the gaseous sample based on the signal. 
     
     
         21 . The method of  claim 20 , further comprising activating an alarm if the concentration of the analyte is greater than a threshold value.