Combined chemoresistive and chemocapacitive microsensor structures

This paper introduces a novel CMOS-compatible multifunctional impedimetric chemical sensor. The sensor features a simple 3-electrode structure to combine resistive and capacitive measurement modes in a three-mask process. With chemically sensitive coatings and different lead configurations, both resistance and capacitance responses upon analyte exposure can be extracted to improve the sensor selectivity. The response of these multifunctional sensors drop-coated with conductive poly(3,4-ethylene-dioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) and non-conductive polyepichlorohydrin (PECH) polymers to different concentrations of alcohol and aromatic hydrocarbon vapors is explored.