Capacitive sensor arrays for the real time detection of volatile organic compounds

Abstract

Capacitive-type gas sensors rely on changes in the dielectric properties of the sensing polymeric layer due to absorption of Volatile Organic Compounds (VOCs) or moisture. They are promising devices in terms of ease and low cost of fabrication, reversibility and the wide range of sensing material choice. In the present work, the aim is to explore the fabrication issues of the InterDigitated Electrodes (IDE) through a generic simulation model for the prediction of the capacitance of various IDE structures. Based on the simulation results, an IDE layout was selected for the realization and evaluation of chemcapacitor arrays in the presence of different humidity levels and low concentrations of VOCs with dielectric constant close to those of polymers. The extracted results will be further exploited for the fabrication optimization of an InterDigitated Capacitor (IDC) layout with increased selectivity and sensitivity in specific applications.