Multifaceted experiments and photothermal simulations based analysis of laser induced graphene and its fibers

The interaction of CO₂ laser with polyimide results in the formation of laser-induced graphene (LIG) and other morphological transitions based on laser parameters, such as Laser-induced fibers (LIF) on the surface. However, a fundamental investigation of LIF, its properties and potential have not been explored until now. We aim therefore to provide novel insights into the LIF by characterization of its structural, electrical, electrochemical, and mechanical properties. Four different morphologies were identified depending on the laser parameters and the temperature required for their formation were quantified by FEM model. Minimum temperatures of 1800 K were required to form LIG and around 2600 to 5000 K to form LIF. High heterogeneity of the LIF along thickness due to temperature gradients, and the existence of sheet structures underneath the fibers were identified. Due to the loosely bound nature of fibers, LIF dispersion was prepared by ultrasonication to functionalize the carbon electrode for electrochemical characterization. The modification with LIF on the electrodes enhanced the electrochemical response of the electrode towards standard redox couple which confirmed the conductive nature of the fibers. This work provides a solid basis for the versatile tuning of the behavior and properties of LIF for potential applications.