Polymer-coated surface acoustic wave sensor arrays for organic vapor detection

Arrays of polymer-coated surface acoustic wave (SAW) vapor sensors have shown great promise for detecting a variety of organic vapors at relevant levels. Both modeling studies and experimental studies have shown that many toxic organic vapors can be detected at or below permissible exposure limits. However, single sensors are not adequately selective for many applications. Sensor arrays with chemometric data processing offer a means to greatly increase the selectivity of the analytical measurement. This raises a number of issues with regard to selecting a set of polymer materials for use in the sensor array. We have recently completed the collection of a large data set where sixteen diverse polymers coated on SAW devices were tested against 18 organic vapors. Chemometric analysis of the data matrix demonstrated the ability to classify nonpolar vapors by compound class, and to distinguish four chlorinated hydrocarbons individually.