The interaction of bacteria on nanopatterned surfaces has caught attention since the discovery of the bactericidal property of cicada wing surfaces. While many studies focused on the inspiration of such surfaces, nanolithography-based techniques are seldom used due to the difficulties in fabricating highly dense (number of pillars per unit area), geometrical nanostructured surfaces. Here we present a systematic modelling approach for optimising the electron beam lithography parameters in order to fabricate biomimicked nanopillars of varying patterned geometries. Monte Carlo simulation was applied to optimize the beam energy and pattern design prior to the experimental study. We optimized the processing parameters such as exposure factor, write field size, pitch, the different types and thicknesses of the PMMA resist used, and the shape of the feature (circle or a dot) for the fabrication of nanopillars to achieve the best lift-off with repeatable result. Our simulation and experimental results showed that a circle design with a voltage of 30 kV and 602 nm thickness of PMMA 495 A4 as base layers and 65 nm of PMMA 950 A2 as top layer achieves the best results. The antibacterial activity was also validated on the representative fabricated titanium nanopillar surface. The surface with a base diameter of 94.4 nm, spike diameter of 12.6 nm, height of 115.6 nm, density of 43 nm/μm2, aspect ratio of 2.16 and centre to centre distance of 165.8 nm was the optimum surface for antibacterial activity. Such a systematic design approach for fabrication of insect wing-mimicked closely packed nanopillars have not been investigated before which provides an excellent platform for biomedical Ti implants.

中文翻译：

---

使用电子束光刻技术在钛上仿生纳米图案蝉翼的系统方法

自从发现蝉翼表面的杀菌特性以来，细菌在纳米图案表面上的相互作用就引起了人们的关注。虽然许多研究都集中在这种表面的启发上，但由于难以制造高密度（每单位面积的柱数）几何纳米结构表面，因此很少使用基于纳米光刻的技术。在这里，我们提出了一种系统建模方法，用于优化电子束光刻参数，以制造具有不同图案几何形状的仿生纳米柱。在实验研究之前，应用蒙特卡罗模拟来优化光束能量和图案设计。我们优化了曝光系数、写入区域大小、间距、所用 PMMA 抗蚀剂的不同类型和厚度等工艺参数，以及用于制造纳米柱的特征的形状（圆形或点），以实现具有可重复结果的最佳剥离。我们的模拟和实验结果表明，以 30 kV 电压和 602 nm 厚度的 PMMA 495 A4 作为基础层和 65 nm 的 PMMA 950 A2 作为顶层的圆形设计达到了最佳效果。抗菌活性也在代表性制造的钛纳米柱表面上得到验证。底径为94.4 nm、穗径为12.6 nm、高度为115.6 nm、密度为43 nm/μm2、纵横比为2.16、中心距为165.8 nm的表面是抗菌活性的最佳表面。