Multifunctional potentiometric gas sensor array with an integrated temperature control and temperature sensors

Abstract

Embodiments of the subject invention relate to a gas sensor and method for sensing one or more gases. An embodiment incorporates an array of sensing electrodes maintained at similar or different temperatures, such that the sensitivity and species selectivity of the device can be fine tuned between different pairs of sensing electrodes. A specific embodiment pertains to a gas sensor array for monitoring combustion exhausts and/or chemical reaction byproducts. An embodiment of the subject device related to this invention operates at high temperatures and can withstand harsh chemical environments. Embodiments of the device are made on a single substrate. The devices can also be made on individual substrates and monitored individually as if they were part of an array on a single substrate. The device can incorporate sensing electrodes in the same environment, which allows the electrodes to be coplanar and, thus, keep manufacturing costs low. Embodiments of the device can provide improvements to sensitivity, selectivity, and signal interference via surface temperature control.

What is claimed is: 
     
         1 . A gas sensor, comprising:
 a sensing electrode in contact with an electrolyte, wherein the electrode is exposed to an environment of interest;   a mechanism capable of altering the temperature of the sensing electrode; and   a detector for measuring an electrical characteristic with respect to the sensing electrode, wherein the measured electrical characteristic provides information with respect to one or more gases in the environment of interest.   
     
     
         2 . The gas sensor according to  claim 1 , wherein the sensing electrode is disposed on a surface of a substrate, wherein the substrate comprises the electrolyte. 
     
     
         3 . The gas sensor according to  claim 1 , wherein the detector measures an EMF between the sensing electrode and a reference. 
     
     
         4 . The gas sensor according to  claim 1 , wherein the detector measures the impedance of the electrode. 
     
     
         5 . The gas sensor according to  claim 1 , wherein the detector measures a current in the electrode. 
     
     
         6 . The gas sensor according to  claim 3 , wherein the measured EMF indicates whether a first gas is present in the environment of interest. 
     
     
         7 . The gas sensor according to  claim 3 , wherein the measured EMF indicates a concentration of a first gas present in the environment of interest. 
     
     
         8 . The gas sensor according to  claim 1 , further comprising:
 at least one additional sensing electrode.   
     
     
         9 . The gas sensor according to  claim 8 , wherein one of the at least one additional electrode is the reference. 
     
     
         10 . The gas sensor according to  claim 1 , wherein the mechanism capable of altering the temperature of the sensing electrode comprises a heater. 
     
     
         11 . The gas sensor according to  claim 10 , wherein the heater is in thermal contact with the electrolyte. 
     
     
         12 . The gas sensor according to  claim 10 , wherein the heater is detached from the electrolyte and sensing electrode. 
     
     
         13 . The gas sensor according to  claim 10 , wherein the heater radiatively heats the sensing electrode. 
     
     
         14 . The gas sensor according to  claim 10 , wherein the heater conductively heats the sensing electrode. 
     
     
         15 . The gas sensor according to  claim 1 , wherein the heater comprises the sensing electrode and a current source for driving the electrode with a current. 
     
     
         16 . The gas sensor according to  claim 1 , wherein the mechanism capable of altering the temperature of the sensing electrode is capable of cooling the sensing electrode. 
     
     
         17 . The gas sensor according to  claim 10 , wherein the heater comprises a heating element, wherein when a heating current is passed through the heating element the heating element produces heat that heats the electrode. 
     
     
         18 . The gas sensor according to  claim 3 , further comprising at least one additional sensing electrode in contact with the electrolyte, wherein the sensing electrode and the at least one additional sensing electrode form an array of sensing electrodes. 
     
     
         19 . The gas sensor according to  claim 18 , wherein the reference is one of the at least one additional sensing electrode, wherein the reference has a different shape than the sensing electrode. 
     
     
         20 . A method of sensing one or more gases, comprising:
 exposing a sensing electrode to an environment of interest, wherein the sensing electrode is in contact with an electrolyte;   altering the temperature of the sensing electrode; and   measuring an electrical characteristic with respect to the sensing electrode, wherein the measured electrical characteristic provides information with respect to one or more gases in the environment of interest.