Fabrication of multifunctional titanium surfaces by producing hierarchical surface patterns using laser based ablation methods

Abstract

Textured implant surfaces with micrometer and sub-micrometer features can improve contact properties like cell adhesion and bacteria repellency. A critical point of these surfaces is their mechanical stability during implantation. Therefore, strategies capable to provide both biocompatibility for an improved implant healing and resistance to wear for protecting the functional surface are required. In this work, laser-based fabrication methods have been used to produce hierarchical patterns on titanium surfaces. Using Direct Laser Writing with a nanosecond pulsed laser, crater-like structures with a separation distance of 50 µm are produced on unpolished titanium surfaces. Directly on this texture, a hole-like pattern with 5 µm spatial period is generated using Direct Laser Interference Patterning with picosecond pulses. While the smaller features should reduce the bacterial adhesion, the larger geometry was designed to protect the smaller features from wear. On the multifunctional surface, the adherence of E. Coli bacteria is reduced by 30% compared to the untreated reference. In addition, wear test performed on the multiple-scale patterns demonstrated the possibility to protect the smaller features by the larger craters. Also, the influence of the laser treatment on the growth of a titanium oxide layer was evaluated using Energy Dispersive X-Ray Spectroscopy analysis.

Aspect ratio of nano/microstructures determines Staphylococcus aureus adhesion on PET and titanium surfaces

“…Wu et al, 2011b). A study showed that holes or craters larger than the bacteria in the surface seem to inhibit the formation of bacteria colonies (Epperlein et al, 2017;C. Zwahr et al, 2019a).…”

Stable Superhydrophobic Aluminum Surfaces Based on Laser-Fabricated Hierarchical Textures

“…First, single-scale textures were produced using both technologies to understand the morphology evolution as a function of the processing parameters and its influence on the wettability characteristics. The targeted DLW texture should not only provide an underlying roughness before the DLIP process to promote a high hydrophobicity, as already demonstrated in earlier publications [ 38 , 48 ], but also it should serve to protect the smaller features produced by DLIP [ 49 ].…”

Laser-Based Ablation of Titanium–Graphite Composite for Dental Application

“…By roughening the implant surface, the healing of the bone can be improved significantly. On the other hand, a very important requirement regarding the implant surfaces are their antibacterial properties [60]; therefore the surface structures with the features slightly smaller than the bacteria size, or the hole/crater-like structures slightly larger than the bacteria size, are used. As documented in this study, the moderately rough surfaces can be produced by laser machining when using lower energy densities (surface S1).…”