Inkjet printed chemical sensor array based on polythiophene conductive polymers

Multiple regioregular polythiophene polymers with a variety of side chains, end groups and secondary polymer chains were used as active sensing layers in a single chip chemresistor sensor array device. A custom inkjet system was used to selectively deposit the polymers onto the array of transduction electrodes. The sensor demonstrated sensitivity and selectivity for detection and discrimination of volatile organic compounds (VOCs). The conductivity responses to VOC vapors are dependent on the chemical structure of the polymers. For certain VOCs, conductivity increased in some polymers, while it decreased in others. Principal component analysis (PCA) of sensor responses was used to discriminate between the tested VOCs. These results are correlated to the chemical structures of the different polymers, and qualitative hypothesis of chemical sensing mechanisms are proposed. This research demonstrates the potential for using such devices in VOC detection and discrimination sensing applications.