ABSTRACT
The capability to detect and quantify chemicals in the atmosphere, together with their concentration, is a source of valuable information for many safety and security applications ranging from pollution monitoring to detection of explosives and drug factories. The network can adapt itself to a variable number of chemical sensors, improving reliability. The characteristics of an optimal sensor for distributed chemical sensing should include low-power operational capability, low cost, long-term reliability, and stability; additionally, it should also be easy to integrate with simple signal conditioning schemes. Most chemical sensors suffer from nonspecificity. Chemical multisensor devices, also called electronic noses, practically exploit the partial overlapping responses of an array of nonspecific sensors to detect and estimate concentrations of several gases simultaneously. State-of-the-art metal oxide chemical sensors require high working temperatures for best sensitivity and specificity. Polymer/Nanocomposite reactivity to chemicals has also been applied to the development of passive resonant sensors that are capable of wireless remote operations in a very simple way.
