Laser engineering methods of novel multi-functional surfaces

Surface functionalization has been a popular research area in recent years. However, the existing fabrication techniques for functional surfaces are either too costly or too time-consuming. Laser-based surface texturing techniques have emerged as a possible solution to this problem due to the advantages of non-contact processing, fast processing speed, and ease of automation.

The objectives of the research presented in this thesis have been to develop innovative laser-based surface texturing processes for efficiently treating multi-functional surface and to further determine the fundamental processing mechanisms. The first process is an innovative nanosecond laser-based high-throughput surface nanostructuring (nHSN) process that efficiently treats large-surface-area engineered metal alloys. The resulting nHSN surface is superhydrophobic and anti-reflective. This method is time-efficient and cost-effective, and the technological breakthrough will render practical treatment of macroscale metal part surfaces. The second process is a novel laser-based metasurface fabrication (LMF) process using transparent glass-based or polymer materials as a substrate. The LMF surface achieves three newly integrated surface functionalities: electrical conductivity, optical transparency, and THz bandpass filtering effect. This innovative laser-based process significantly improves efficiency and reduces production cost compared with the existing laser surface patterning methods.

Key applications of the nHSN and LMF surfaces are experimentally demonstrated. The fundamental process mechanisms of the LMF process is elucidated by developing numerical models to simulate the THz transmission of the LMF surfaces. The good agreement between the simulation results and experimental results indicates that LMF process is a promising method for fabrication of transparent conducting THz bandpass metamaterials. These two innovative laser-based surface engineering methods will not only provide new avenues for functional surface fabrication but will also render key advancements for the fundamentals of laser-matter interactions, thus benefiting various industry sectors.