A novel circuit model of nanotechnology-enabled inkjet-printed gas sensors using multi-wall carbon nanotubes

This paper presents a novel electrical model of multi-walled carbon-nanotube based gas sensors completely patterned using low-cost inkjet printing. The obtained results (validated through measurements from 50 MHz to 3 GHz) demonstrate that the nanostructure-based sensing mechanisms yields a quite evident shift of circuit resistive elements. A narrowband investigation of the resistive variation depending on gas concentration has been performed as well. The input impedance has been found to be significantly lower than that reported for metal oxide sensors, thus facilitating the integration in electronic circuitry. The suggested equivalent model can be exploited in the implementation of large-scale nanotechnology-enabled inkjet-printed modules.