Non-traditional Measurement Approaches for Chemical Analyte Detection

Chemical sensing using low cost materials, especially thin film semiconductors and printable nanocrystals, has been a long-standing goal of the gas sensing community for the creation of low cost and low power chemical detection systems. The selectivity of these materials is relatively low, however, so a combinatorial approach to classification of analytes has been applied. One of the significant improvements to the classification of resistive signals has been the use of measurements beyond resistivity- examining, for example, induced charge carrier density, changes in material transport characteristics, and the formation of fixed charges. This review examines both the history and some of the recent advances using this approach.