Optimization of Composite Polymer Gas Sensor Arrays for Single-Analyte Multiple-Interferent Applications

D.M. Wilson and Sam McKennoch

Results for optimizing an array of composite polymer gas sensors for sensing one of five analytes in the presence of up to four interferents are presented. The optimized array consists of a heterogeneous array of up to ten points (unlike sensors) in multi-dimensional sensor space. The optimization techniques presented here are linear, since the composite polymer sensors in their useful (low concentration) operating range exhibit linear and additive response characteristics. The optimization of these arrays produces maximum separability between analytes, demonstrating the trade-off between the addition of both information and variability induced by increasing the size of the heterogeneous array. Optimization results for sensing acetone, hexane, thf, toluene, and ethanol in the presence of interferents result in array sizes that are significantly less than the maximum available number of sensors (10). This result adds fuel to the argument that fewer sensors are better; the argument for more sensors is also made in the context of the electronic nose systems where significant chemical diversity is required.