Bougdid Yahya, Sekkat Zouheir
Department of Chemistry, Faculty of Sciences, Mohammed V University in Rabat, Rabat, Morocco.
Optics and Photonics Center, Moroccan Foundation for Advanced Science & Innovation & Research, MAScIR, Rabat, Morocco.
Sci Rep. 2020 Jun 26;10(1):10409. doi: 10.1038/s41598-020-67184-2.
Voxels, the 3D equivalent of 2D pixels, are obtained by individual point exposures in 3D laser nanoprinting, and are the building blocks of laser printed 3D micro/nano-structures, and their optimization is important in determining the resolution of printed 3D objects. Here, we report what is believed the first detailed study of the voxel size dependence on the z-potion of the laser spot in 3D nano-printing. That is, we study the evolution and the low-limit size (diameter and length) of voxels fabricated in the vicinity of the substrate/resin interface. We use two-photon absorption in a photopolymerizable resin, and we vary the position of the laser's focal spot, with respect to the cover glass/resin interface; i.e. in the longitudinal direction (z-direction). We found that the minimum lateral and the longitudinal sizes of complete voxels depend on the extent of penetration of the laser focal spot inside the resin. Truncated voxels, which are fabricated by partial overlap of the resin and the laser spot, allow for the fabrication of nano-features that are not diffraction limited, and we achieved near 100 nm feature sizes in our 3D fabricated objects. Our work is of central interest to 3D nanoprinting, since it addresses the spatial resolution of 3D printing technology, and might have potential impact for industry.
体素是二维像素的三维等效物，通过三维激光纳米打印中的单个点曝光获得，是激光打印三维微纳结构的基本构建单元，其优化对于确定打印三维物体的分辨率至关重要。在此，我们报告了一项据信是首次关于三维纳米打印中体素尺寸对激光光斑z位置依赖性的详细研究。也就是说，我们研究了在基底/树脂界面附近制造的体素的演变及其下限尺寸（直径和长度）。我们在可光聚合树脂中利用双光子吸收，并相对于盖玻片/树脂界面改变激光焦点的位置，即在纵向（z方向）上。我们发现完整体素的最小横向和纵向尺寸取决于激光焦点在树脂内部的穿透程度。通过树脂和激光光斑部分重叠制造的截断体素能够制造不受衍射限制的纳米特征，并且我们在三维制造物体中实现了接近100纳米的特征尺寸。我们的工作对于三维纳米打印至关重要，因为它解决了三维打印技术的空间分辨率问题，并且可能对工业产生潜在影响。
