Combustion conditions discrimination properties of Pt-doped TiO2 thin film oxygen sensor

Present work focuses on evaluation of microfabricated Pt-doped titanium oxide thin film sensors capability to discriminate different combustion conditions of a real gasoline engine; actually, zirconia-based lambda probes are a well-established technology in the field of combustion control for fuel injection engines, but these devices suffer high production cost. A cheap mass fabrication method to produce thin film platinum-doped titania sensors is presented, together with an experimental validation of performances under real working conditions. A dedicated experimental bench enabled simultaneous data acquisition of a Bosch lambda probe Mod. LSF 4.2 and the Pt-doped TiO2 thin film sensor fabricated onto ceramic alumina substrates. Three different operative temperatures were investigated concerning response times and successful classification rate; a simple threshold-based ON/OFF data analysis allows satisfactory results about discrimination between rich and lean combustion conditions.