Optimisation and fabrication of a calorimetric gas sensor built up on a polyimide substrate for H2O2 monitoring

A calorimetric gas sensor for the detection of vapourised H2O2 in aseptic filling processes was built up on a polyimide foil instead of silicon as substrate material in order to optimise the sensor response behaviour. The sensor was catalytically activated with a dispersion of manganese(IV) oxide. The reaction mechanism of the exothermic H2O2 decomposition on the catalyst involves two pathways: an initial reaction with electron exchange between the catalyst surface and H2O2 creating free radicals, and a chain reaction of these radicals with H2O2, in which the final products, namely water and oxygen, are formed. The calorimetric gas sensor possesses a linear response behaviour with a sensitivity of 7.15 °C/(% v/v) in a H2O2 concentration range from 0 to 8% v/v. Calorimetric gas sensor on polyimide foil for H2O2 monitoring in sterilisation processes.