One-Step Fabrication of Low-Resistance Conductors on 3D-Printed Structures by Laser-Induced Graphene

Three-dimensional (3D) printing is becoming increasingly prevalent in the manufacturing of goods for different applications. Many of these applications will benefit from the integration of electronics into 3D-printed structures. In this study, we report a fabrication method to convert 3D-printed polyetherimide (PEI) into graphene by exposing it to a scanned laser beam. This laser-induced graphene (LIG) is not only conductive but also has a large gauge factor for mechanical strain sensing. We have achieved a sheet resistance of 0.30 Ω/sq which is 50 times lower than that of previous reports on 3D-printed PEI/PC sheets and the lowest LIG sheet resistance value reported to date on any polymer substrate. This is achieved due to three main factors: large thickness of LIG on a 3D-printed object, maximization of the laser energy per unit area, and improved LIG morphology on 3D-printed PEI compared with that on commercial PEI.