Laser Direct Writing of Flexible Heaters on Polymer Substrates

Conventional flexible film heaters composed of a resistive element are prepared by etching metal foil and a polymer insulating layer. The fabrication of flexible film heaters directly onto polymer substrates is an ever-increasing challenge. Herein, flexible laser-induced graphene (LIG) film heaters with excellent electrothermal performances were fabricated on polyimide (PI) substrates directly through 9.3 mu m CO2 laser irradiation under ambient conditions. Physical morphology and chemical composition characterizations confirmed the generation of sp(2)-hybridized LIG from the PI precursor. The main factor that affected laser radiation was the adjacent distance between laser scanning lines under a fixed laser energy. The fabricated flexible heater exhibited excellent heating performance and maintained physical robustness and thermal performance after repeated bending. This effective and environmentally friendly strategy paves the way for fabricating flexible heating devices on polymer surfaces.