Flexible and robust laser-induced graphene heaters photothermally scribed on bare polyimide substrates

We demonstrate the feasibility of fabricating cost-effective and robust laser-induced graphene (LIG) flexible heaters with an innovative technique based on the photothermal production of graphene with a foam-like morphology. The produced devices are precisely defined on a bare polyimide substrate without the need of photomasks by employing a computer numerical control (CNC) driven laser diode. The electrical properties of the LIG-based heaters can be tailored by adjusting the laser power. The resulting conductive material exhibits electrical and chemical properties which are similar to the ones for graphene such as a negative temperature coefficient of -0.46 m degrees C-1 and a maximum operating temperature of around 400 degrees C. The developed heaters can outperform the existing emerging technologies showing a very rapid and stable response up to 225 degrees C with the extra features of flexibility, biocompatibility, and environmental friendliness. (C) 2018 Elsevier Ltd. All rights reserved.