No abstract

In recent years, printed and flexible gas sensors have quickly emerged as an innovative area of great interest because of their lightness and low cost.

The fabrication of printed electronic devices based on metal oxide inks requires the formulation of stable suspensions with specific fluidic properties. In our work, a tin oxide based solution was synthetized by aqueous sol-gel method, and transformed into an ink with appropriate viscosity and surface tension to be inkjet-printed on polyimide foil and sintered at relatively low temperature. Thermal analysis by TGA/DSC and microstructural analysis by XRD of synthetized sol show that a crystallized structure of SnO2 could be obtained at 350°C, which is lower than crystallization temperatures of SnO2 previously reported in the literature, and entirely consistent with the use of polyimide foil. The stability and the rheological properties of the ink were studied to ensure the jettability criteria of the inkjet-printer. Electrical measurements of the printed sensing films were performed to characterize the response to CO gas in different concentrations, at working temperature of 300°C.