MJC, SHC, and YP characterized
LY3023414 in vitro the catechin-AuNPs. YSK, SC, and YP supervised the entire process and drafted the manuscript. All authors read and approved the final manuscript.”
“Background There are a lot of approaches to treat substrate-bound thin films by pulsed lasers in order to modify the structure, morphology, or functionality of these layers. Either the internal physical or chemical properties are modified maintaining the external shape (annealing, crystallization, transformation), a well-known example of which is the crystallization of amorphous silicon on glass for display applications [1], or the external morphology is changed, which is the case, e.g., for dewetting [2] or (partial) ablation. Patterning of thin metallic, semiconducting, or dielectric films by laser ablation has been extensively studied, and numerous applications BMN 673 chemical structure utilizing this method have been developed [3]. There are also ablation processes aimed at spatially selective deposition of material on another substrate, this process being named selleck screening library laser-induced forward transfer (LIFT) [4]. If the ablation/transfer is incomplete in
that sense that the layer detaches from the substrate in some area, but the film is still not perforated, blister formation is observed [5]. In this paper, we describe a method utilizing the space-selective laser-induced film detachment together with some morphology change due to heating and surface tension to create substrate-bound grid structures with micron to nanometer Sunitinib research buy dimensions. The fabrication of such grids from silica material relies on the combination of two fundamental conditions of laser ablation. First, effective and controlled material response is possible only if the laser radiation is strongly absorbed by the treated material. As well-controlled absorption of laser light in silica (SiO2) is impeded by the transparency
of this material, we choose highly absorbing silicon suboxide (SiO x , x ≈ 1) as primary material for laser treatment, which can be oxidized to SiO2 after the laser-induced shape-forming process [6]. Second, shape control in laser ablation is strongly enhanced by the so-called confinement. A liquid or a polymer layer in contact with the surface to be ablated serves for smooth, contiguous bulges around the ablation holes instead of irregular splashes observed without this confinement [7]. In standard ablation configurations, this confinement material has to be transparent for the laser radiation, because the laser beam has to pass it before being absorbed at the surface of the material to be ablated. Therefore, it is preferably applied in the form of thin layers. Using a rear side configuration, where the beam is guided through the substrate onto the film [8], this transparency is not that critical, i.e., thick layers can be used for confinement.