Preliminary analysis on cellulose-based gas sensor by means of aerosol jet printing and photonic sintering

In this paper, we present a preliminary analysis on the possibility to realize low-cost and eco-friendly cellulose-based gas sensors by means of Aerosol Jet Printing (AJP) and flash lamp annealing (FLA). To the authors knowledge, it is the first time that these two techniques are combined in the realization of such a device. The intrinsic hygroscopic properties are the key element of this device: cellulose contains substantial amount of moisture, adsorbed from the environment, enabling the use of wet chemical methods for sensing without manually adding water to the substrate. The sensors were tested in terms of electrical resistance. The penetration of the carbon ink in the cellulose network was stated thanks to cross-sections captured at the microscope. Once placed in a damp environment, all the sensors showed a comparable behavior settling at an asymptotic value of 3.68 MΩ (relative standard deviation of 8%). In presence of different concentration of NH4OH, the sensors showed a resistance proportional to the amount of analyte present in the working volume, showing 25.6% increase compared to the 0.5 M concentration, while 34.1% compared to the 1M.