Thermal-needle-triggered cascade reduction of graphene oxide for controllable moving trajectory into conductive patterns.

We showed graphene patterning could be triggered with a thermal needle and controlled through pre-infiltrating certain materials into graphene oxide (GO) substrates. With an appropriate O/C molar ratio of GO (≥0.4) and physical density (≥3 mg cm -3 ), a cascade reduction reaction of GO films/aerogels was triggered by a needle with a temperature as low as 195 °C and propagated at a high rate of up to ∼320 mm s -1 . The thermal reduction mechanism could also provide a clue for laser writing on GO substrates without the occurrence of cascade reduction for high precision. More importantly, this study offers a promising approach for graphene patterning by triggering with a hot needle and controlling with pre -infiltration of hydrophilic materials.