Controlling the laser induction and cutting process on polyimide films for kirigami-inspired supercapacitor applications

The recently emerging laser-induced graphene (LIG) technology, with one-step processing and designable features, has been widely used in the fabrication of wearable/portable electronics. Herein, by taking inspiration from kirigami, we designed a stretchable supercapacitor (SC) step by step through controlling laser induction and cutting process on the polyimide (PI) film, with the use of one single CO2 laser source. Firstly, the carbonized basic geometric units of lines were produced on PI films to investigate the processing-structure relationships. Then, the complex photothermal conversion and heat transfer progress involved in the carbonized process were simulated by a photothermal model. Both experimental and theoretical results suggested that the laser power, scan rate and focus condition have great influence on the size, shape and morphology of the carbonized lines. Finally, we optimized the parameters of laser induction and cutting process to fabricate the kirigami-inspired SCs with reliable electrochemical properties and editable mechanical flexibility, showing great potential in the field of flexible electronics.