Gas sensing device and a method for sensing gas

Abstract

A method and a gas sensing device are provided. The gas sensing device may include a bulk and an array of gas sensing elements that are thermally isolated from the bulk, wherein each gas sensing element of a plurality of gas sensing elements of the array comprises (i) a gas reactive element that has a gas dependent temperature parameter; and (ii) a semiconductor temperature sensing element that is thermally coupled to the gas reactive element and is configured to generate detection signals that are responsive to a temperature of the gas reactive element.

We claim: 
     
         1 . A gas sensing device, comprising a bulk and an array of gas sensing elements that are thermally isolated from the bulk, wherein each gas sensing element of a plurality of gas sensing elements of the array comprises (i) a gas reactive element that has a gas dependent temperature parameter; and (ii) a semiconductor temperature sensing element that is thermally coupled to the gas reactive element and is configured to generate detection signals that are responsive to a temperature of the gas reactive element. 
     
     
         2 . The gas sensing device according to  claim 1 , wherein each gas sensing element of the plurality of gas sensing elements comprises a plurality of gas reactive elements and a plurality of semiconductor temperature sensors; each semiconductor temperature sensing element is thermally coupled to a single gas reactive element and is thermally isolated from other semiconductor temperature sensors of the multiple semiconductor temperature sensors. 
     
     
         3 . The gas sensing device according to any of the preceding claims, further comprises at least one reference sensing element that comprises a semiconductor temperature sensing element that is not thermally coupled to a gas reactive element. 
     
     
         4 . The gas sensing device according to any of the preceding claims, wherein at least two gas sensing elements of the array are configured to sense different gases. 
     
     
         5 . The gas sensing device according to any of the preceding claims, wherein at least two gas sensing elements of the array differ from each other by their gas reactive elements. 
     
     
         6 . The gas sensing device according to any of the preceding claims, wherein at least two gas sensing elements of the array have a same gas reactive element. 
     
     
         7 . The gas sensing device according to any of the preceding claims wherein the semiconductor temperature sensing element is configured to heat the gas reactive element to at least one predefined temperature. 
     
     
         8 . The gas sensing device according to any of the preceding claims wherein each gas sensing element the plurality of gas sensing elements further comprises a heating element that is configured to heat the gas reactive element to at least one predefined temperature. 
     
     
         9 . The gas sensing device according to  claim 8 , wherein in each gas sensing element the plurality of gas sensing elements the heating element surrounds the semiconductor temperature sensing element. 
     
     
         10 . The gas sensing device according to  claim 8 , wherein in each gas sensing element the plurality of gas sensing elements the heating element is spaced apart from the semiconductor temperature sensing element. 
     
     
         11 . The gas sensing device according to any claim of  claims 8 - 10 , wherein in each gas sensing element the plurality of gas sensing elements the heating element is a polysilicon resistor that is spaced apart from the semiconductor temperature sensing element. 
     
     
         12 . The gas sensing device according to any claim of  claim 8 - 11 , wherein the at least one predefined temperature comprises multiple predefined temperatures that are associated with a sensing of multiple gases that differ from each other; wherein in each gas sensing element the plurality of gas sensing elements the heating element is configured to heat the gas reactive element, at different points in time, to the multiple predefined temperatures. 
     
     
         13 . The gas sensing device according to any claim of  claims 8 - 12  wherein each heating element that is configured to heat the gas reactive element in a non-continuous manner. 
     
     
         14 . The gas sensing device according to any of the preceding claims, further comprising a signals source, an interfacing module and a readout circuit; wherein the interfacing module electrically couples the array to the signals source and to the readout circuit; wherein the signals source is configured to supply bias signals to at least one gas sensing element of the array; wherein the readout circuit is configured to read detection signals from one or more. 
     
     
         15 . The gas sensing device according to  claim 14  wherein each gas sensing element further comprises a heating element that is configured to heat the gas reactive element to at least one predefined temperature; and wherein the signals source is further configured to supply bias signals to heating elements of the array. 
     
     
         16 . The gas sensing device according to any claim of  claims 14 - 15  wherein the signals source is configured to provide pulsed bias signals. 
     
     
         17 . The gas sensing device according to any claim of  claims 14 - 16  wherein the signals source is configured to provide bias current signals; and wherein the detection signals are voltage detection signals. 
     
     
         18 . The gas sensing device according to any claim of  claims 14 - 16  wherein the signals source is configured to provide to the gas sensing elements of the array at least one voltage bias signal; and wherein the detection signals are current detection signals. 
     
     
         19 . The gas sensing device according to any claim of  claims 14 - 16  wherein the readout circuit is configured to read differential detection signals. 
     
     
         20 . The gas sensing device according to any of the preceding claims wherein each gas sensing element the plurality of gas sensing elements is mechanically supported by at least supporting element. 
     
     
         21 . The gas sensing device according to any of the preceding claims wherein each gas sensing element the plurality of gas sensing elements is mechanically supported by a plurality of spaced apart supporting elements. 
     
     
         22 . The gas sensing device according to any of the preceding claims wherein the bulk is micro-machined or nano-machined to form a gap between the bulk and the array of gas sensing elements. 
     
     
         23 . The gas sensing device according to any of the preceding claims, wherein in each gas sensing element the plurality of gas sensing elements the semiconductor temperature sensing element is a Complementary Metal Oxide Semiconductor (CMOS) temperature sensor. 
     
     
         24 . The gas sensing device according to any of the preceding claims wherein the array comprises a plurality (N) of gas sensing elements that are configured, at a certain point in time, to differ from each other by their response to materials; wherein the gas sensing device is configured to detect a composition of up till N different gaseous materials by processing the detection signals from the plurality of gas sensing elements. 
     
     
         25 . A method for sensing gas by a gas sensing device, the method comprises:
 heating to a predefined temperature a gas reactive element that belongs to a gas sensing element and has a gas dependent temperature;   generating, by a semiconductor temperature sensing element that belongs to the gas sensing element and is thermally coupled to the gas reactive element, detection signals that are indicative of a temperature of the gas reactive element; wherein the gas sensing element is thermally isolated from a bulk of a gas sensing device;   processing, by a readout circuit of the gas sensing device, the detection signals to provide information about gas that affected the temperature of the gas reactive element.