Fabrication of flexible room-temperature NO2 sensors by direct laser writing of In2O3 and graphene oxide composites

In this work, we reported the fabrication of flexible NO 2 sensors arrays operating at room temperature on a composite film of In 2 O 3 and graphene oxide (GO) by direct laser writing (DLW) technology. The laser treatment not only induced the photoreduction of GO , leading to a highly porous structure due to the removal of oxygen groups, but also permitted mask-free patterning through a programmable manner, enabling flexible integration of sensor arrays on any substrates. We demonstrated the fabrication of a 2 × 4 NO 2 sensors array on a flexible polyimide substrate within 10 min. Our NO 2 sensors based on In 2 O 3 and reduced GO (In 2 O 3 @RGO) show liner NO 2 sensing properties at room temperature, good responsivity and recovery properties, as well as excellent selectivity towards NO 2 . We deem that the DLW fabrication of flexible NO 2 sensorsarrays may contribute to the development of flexible electronics.