Toxic Gas Array Sensor Based on Chemiresistors

Sharon Marx, Physical Chemistry, IIBR, Ness Ziona, Israel
Gil Feldheim, Physical Chemistry, Iibr, Ness Ziona, Israel
Guy Cohen, Environmental Physics, Iibr, Ness Ziona, Israel
Noach Shalom, Assistance Department, Iibr, Ness Ziona, Israel

The development of a chemiresistor (CR) sensor array for the detection of chlorine and ammonia in the air, in concentrations ranging from TLV to IDLH will be described. The sensors are based on simple, inexpensive resistor elements that are coated with a variety of selective and sensitive coatings made of engineered nanomaterials. Application of a thin film of the nanomaterails on the surface of the chemiresistor yield the sensing element. Once the sensor is exposed to the target material, it adsorbes the material in a reversible fashion into the sensing layer, and changes the initial resistance of the element. Monitoring the responses of an array of varied sensors will give a characteristic pattern that can be analyzed. Chemiresistor sensors hold a great potential for applications like wearable sensors, due to their small size, ultralow energy consumption and simple measurement. The application of the sensors to measure ammonia and chlorine will be described.