Abstract Laser-induced graphene (LIG) is a promising technique for producing highly organized graphene patterns in a controlled way on carbon-rich materials but the current state of the art is limited to continuous wave or long-pulsed lasers. In this work, a femtosecond (fs) laser with an infrared wavelength (1030 nm) and a pulse duration of 200 fs was utilized to directly induce graphene tracks on rough 3D-printed polyetherimide (ULTEM-9085) substrates. The inherent surface roughness of the 3D-printed sample and the print defects leads to significant challenges in achieving uniform and continuous graphene formation, which has been addressed through the regulation of the laser focus. By precisely overlapping multiple laser-induced graphene (LIG) tracks, a continuous LIG area was successfully produced, demonstrating the feasibility of large-area graphene patterning on rough polymeric substrates. Moreover, a secondary laser scan at lower laser fluence was applied to the pre-formed LIG, leading to an enhancement in the electrical conductivity. This improvement is attributed to further structural re-organization, defect reduction, and potential removal of insulating polymer residues. The proposed approach provides an efficient and scalable strategy for fabricating conductive graphene patterns on complex polymeric surfaces, with potential applications in flexible electronics, sensors, and energy storage devices.
Shiby et al. (Thu,) studied this question.