Surface improvement of implants is essential for achieving a fast osseo-integration. Technically, the creation of a precise pattern on a titanium alloy surface is challenging. Here, the femtosecond laser was chosen as an innovative technology for texturing with accuracy a nano-micro topography. By adjusting the laser parameters, three biomimetic textures were fabricated on the titanium surface: micropits with nano-ripples in the pits, micropits with nano-ripples around the pits, and a texture with only nano-ripples. Mesenchymal stem cells (MSCs, C3H10T1/2) grown on these surfaces displayed altered morphometric parameters, and modified their focal adhesions in term of number, size, and distribution depending on surface type. These results indicate that the MSCs perceived subtle differences in topography. Dynamic analyses of early cellular events showed a higher speed of spreading on all the textured surfaces as opposed to the polished titanium. Concerning commitment, all the laser-treated surfaces strongly inhibited the expression of adipogenic-related genes (PPARϒ2, C/EBPα) and up-regulated the expression of osteoblastic-related genes (RUNX2, osteocalcin). Interestingly, the combination of micropits to nano-ripples enhanced their osteogenic potential as seen by a twofold increase in osteocalcin mRNA. Alkaline phosphatase activity was increased on all the textured surfaces, and lipid production was down-regulated. The functionalization of metallic surfaces by this high-resolution process will help us understand the MSCs' interactions with substrates for the development of textured implants with predictable tissue integrative properties.

Planar electrochemical microcells were micromachined in a microcrystalline boron-doped diamond (BDD) thin layer using a femtosecond laser. The electrochemical performances of the new laser-machined BDD microcell were assessed by differential pulse anodic stripping voltammetry (DPASV) determinations, at the nanomolar level, of the four heavy metal ions of the European Water Framework Directive (WFD): Cd(II), Ni(II), Pb(II), Hg(II). The results are compared with those of previously published BDD electrodes. The calculated detection limits are 0.4, 6.8, 5.5, and 2.3 nM, and the linearities go up to 35, 97, 48, and 5 nM for, respectively, Cd(II), Ni(II) Pb(II), and Hg(II). The detection limits meet with the environmental quality standard of the WFD for three of the four metals. It was shown that the four heavy metals could be detected simultaneously in the concentration ratio usually measured in sewage or runoff waters.

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Femtosecond laser engraving offers appealing advantages compared to regular laser engraving such as higher precision and versatility. In particular, the inscription of deep patterns exhibits an increasing interest in industry. In this work, an optimization protocol based on constraining overlap ratio and scan number is demonstrated. The proposed method allows changing overlap ratio while maintaining depth in the same range, which reduces the sampling number. This study WAS applied to stainless steel 316 L and sapphire for engravings deeper than 100 μm. Results exhibit overall depths higher than threshold values and allowed to determine optimized engraving quality, for instance, roughness in steel can be reduced while maintaining depth and taper angle by reducing overlap ratio. The optimized laser parameters such as roughness and taper angle factors for sapphire were also found to be as follows: 200 kHz, 86% overlap and 12 J/cm2. As a demonstration, a logo engraving is illustrated at the end.