Laser scribing of Ag-decorated graphene for high-performance and flexible heaters

In this article, Ag nanoparticle decorated graphene-based film heaters are fabricated using a CO₂ infrared laser writing technology. In this process, we use the commercial polyimide (PI) as carbon sources which can be directly converted into graphene during the laser irradiation. To prepare the Ag decorated graphene, the PI films are modified with KOH into potassium polyamate and incorporation of Ag⁺ ions through subsequent ion exchange prior to the laser irradiation. While the laser is irradiating on silvered PI, the temperature of the irradiated silvered PI increases in a flash leading to the reduction of Ag⁺ ions on the PI derived graphene (PDG) surface. The resultant Ag-decorated PDG (Ag-PDG) composites reveal an enhanced electric conductivity (16.2 Ω/sq.) with excellent mechanical properties. The flexible heaters constructed from the Ag-PDG film also show remarkable electrothermal performance in terms of saturated temperature (Ts, 248.3 °C), heating efficiency (142.8 °C cm²/W), response time (2.14 s) and durability with a small temperature deviation (1.3 °C) after 2000 bending cycles.