Direct Laser Interference Patterning of Zirconia Using Infra-Red Picosecond Pulsed Laser: Effect of Laser Processing Parameters on the Surface Topography and Microstructure

This study investigates the influence of processing parameters when applying direct laser interference patterning (DLIP) on the morphology and microstructure of zirconia surfaces using a 10 ps-pulsed laser source with 1064 nm wavelength. An experimental testing matrix is built with different values of laser fluence (5.7-18.2 J cm-2) and pulse overlap (66-98%). Surface morphology and microstructure are characterized by confocal microscopy and scanning electron microscopy. Homogeneous line-like patterns with periodic spatial repetition of 5.0 & mu;m, with varying depths, widths, and aspect ratio, are fabricated using proper processing parameters (5.7-7.6 J cm-2 and 92-96%). Structures with maximum depth of 1.5 & mu;m and sharp edges are obtained (7.6 J cm-2 and 96% overlap). Ablated regions presented a morphology typical of photophysical ablation mechanism, with signs of molten material at the surface. Sub-micrometric pores and nanodroplets are registered for all conditions, while sub-micrometric cracks developed only for higher fluences. A processing window conducing to homogenous DLIP structures is set based on experimental data. Periodic structures with multiscale topographic features are successfully obtained on zirconia surfaces using DLIP technology in this study. These outcomes open new perspectives for fabrication of multifunctional zirconia surfaces for advanced biomedical and engineering applications. Direct laser interference patterning (DLIP) is a novel technique that allows the creation of micrometric periodic structures on the surface of different materials. In this study, the DLIP is used with a picosecond pulsed laser to generate line-like structures on zirconia's surface using different parameters. Homogeneous patterns with 5 & mu;m periodicity and depths up to 1.5 & mu;m are successfully created.image

Automated summary

This study investigates the influence of processing parameters on the morphology and microstructure of zirconia surfaces using direct laser interference patterning (DLIP). Homogeneous line-like patterns with varying depths, widths, and aspect ratio are successfully fabricated using proper processing parameters. Ablated regions show signs of photophysical ablation mechanism. Sub-micrometric pores and nanodroplets are registered for all conditions, while sub-micrometric cracks are developed only for higher fluences. These results have important implications for the fabrication of multifunctional zirconia surfaces for advanced biomedical and engineering applications.