An inkjet-printed rGO-PEI composite for CO2 monitoring working at room temperature

A printable ink-based composite of rGO and PEI has been prepared for carbon dioxide (CO
2
) sensing. The composite ink was applied to an array of interdigitated electrodes using automated inkjet printing on a silicon wafer scale. Sensing performances at room temperature of CO
2
at different concentrations from 400 to 2000 ppm has shown a response up to 26%. Long-time stability, repeatability, response time and recovery time were investigated. The jettability of the ink is optimized by tuning nozzles waveform, jetting voltage and cartridge temperature. The performance of the fabricated sensors demonstrates the great potential of nanocomposites for the detection of CO
2
at room temperature and the suitability of the inkjet printing method for integrating sensing materials with electronic devices on a mass production scale, for application fields where economical sensors with low power consumption are required.