Texturing of transparent polymers for surface functionalization has become an increasingly significant area of research and technological advancement. This process involves modifying the surface of these materials to enhance their functionalities, such as wettability, adhesion, optical transmission or biocompatibility.[1] Several cutting-edge techniques and approaches have been explored, contributing to the evolution of this field, such as electrospinning, plasma treatment, or laser-based methods. Particularly, laser ablation and microstructuring have emerged as powerful techniques for precisely modifying the surface of transparent polymers. Pulsed lasers allow for high precision and minimal heat-affected zones, making them suitable for creating intricate microstructures. The resolution of the ablated features can be improved by using the Direct Laser Interference Patterning (DLIP) method, whereby two or more laser beams are overlapped on the material surface generating an interference pattern.[2] This work presents a novel design of a two-beam DLIP system based on a high-power (4 W) ns-laser source emitting UV light (266 nm) for structuring transparent polymers. The laser beams are guided over the polymer by a galvoscanner and focused on the sample surface by an f-theta lens. The spatial period of the engraved microtexture can be tuned between 2 and 5 µm by changing the overlapping angles between the beams. Furthermore, the system is designed to work as a stand-alone solution or for running on a roll-to-roll system for mass production. The preliminary experiments are performed on polycarbonate (PC) foils, which are structured with line-like patterns with different spatial periods and depths, demonstrating the feasibility of the proposed design.

References

[1] A. Shakeri; N. Abu Jarad; S. Khan; T. F. Didar Analytica Chimica Acta, 2022, 1209, 339283.

[2] L. Mulko; M. Soldera; A.F. Lasagni Nanophotonics, 2021, 11, 203-240.