Ammonia sensing properties of ZnO nanoparticles on flexible substrate

We report the ammonia gas sensing properties of ZnO nanoparticles on flexible substrates. The flexible platform contains Ti/Pt interdigitated electrodes for gas detection and a micro heater device. The Ti/Pt film has been deposited by Magnetron Sputtering with thickness of 5nm and 100 nm respectively. The circuit patterning has been fabricated by standard photolithography and femtosecond laser ablation processes. ZnO thin film has been deposited by drop coating process with a thickness of 275 nm and the gas sensing properties towards ammonia have been studied. The physical properties obtained by both processes have been observed and theirs effects on the gas sensitivity have been discussed. Despite there are small variations in the physical characteristics between the samples fabricated by different patterning processes, both devices present high sensitivity and reproducibility to different ammonia concentrations from 5 ppm to 100 ppm at 300 °C.