Abstract Functional surfaces have gained a lot of interest due to enhancement in water repellency for advanced engineering applications. In the present era, single and multi-level texturing is usually carried out on surfaces for inducing complete water repellency. The role of a hierarchical textured surface for enhancing the contact angle (CA), however, has not been extensively studied and understood. In the present work, the physical interpretation of water droplet activity on a hierarchical textured surface has been studied by the development of a mathematical model taking into account different forces responsible for inducing water repellency. Subsequently, hierarchical textured surface i.e., arrays of major pillars with rectangular sub-micron minor pillars over its top surface, were fabricated with high precision by using a diamond turn machining (DTM) process. The fabricated hierarchical textured surfaced was investigated based on the structural dimension and static CA. Also, the effects of variation of spacing between major pillars (p), the ratio of spacing between minor pillars to the minor pillar width ( k = p s w t ) and ratio of minor pillar to major pillar width ( v = w t w ) with CA were studied. The developed mathematical model was able to predict the water CA with dimensions similar to experimentally fabricated hierarchical textured surface with an error of 6.67%. The model is capable of designing and optimizing the hierarchical textured surface of various sizes, which enables their manufacturing in a cost-effective way.

中文翻译：

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用于诱导拒水性的金刚石车削分层纹理表面：分析模型和实验研究

摘要 由于在高级工程应用中增强了拒水性，功能性表面引起了人们的广泛关注。在当今时代，通常在表面上进行单级和多级纹理化以诱导完全防水。然而，分级纹理表面在提高接触角 (CA) 方面的作用尚未得到广泛研究和理解。在目前的工作中，已经通过数学模型的发展研究了分层纹理表面上水滴活动的物理解释，同时考虑了导致拒水性的不同​​力。随后，分层纹理表面，即在其顶表面上具有矩形亚微米次要支柱的主要支柱阵列，通过使用金刚石车削加工 (DTM) 工艺以高精度制造。基于结构尺寸和静态 CA 研究了制造的分层纹理表面。此外，还研究了主柱间距（p）、小柱间距与小柱宽度比（ k = pswt ）和小柱与主柱宽度比（ v = wtw ）对CA的影响。 . 开发的数学模型能够预测具有与实验制造的分层纹理表面相似的尺寸的水 CA，误差为 6.67%。该模型能够设计和优化各种尺寸的分层纹理表面，从而能够以具有成本效益的方式进行制造。基于结构尺寸和静态 CA 研究了制造的分层纹理表面。此外，还研究了主柱间距（p）、小柱间距与小柱宽度比（ k = pswt ）和小柱与主柱宽度比（ v = wtw ）对CA的影响。 . 开发的数学模型能够预测具有与实验制造的分层纹理表面相似的尺寸的水 CA，误差为 6.67%。该模型能够设计和优化各种尺寸的分层纹理表面，从而能够以具有成本效益的方式进行制造。基于结构尺寸和静态 CA 研究了制造的分层纹理表面。此外，还研究了主柱间距（p）、小柱间距与小柱宽度比（ k = pswt ）和小柱与主柱宽度比（ v = wtw ）对CA的影响。 . 开发的数学模型能够预测具有与实验制造的分层纹理表面相似的尺寸的水 CA，误差为 6.67%。该模型能够设计和优化各种尺寸的分层纹理表面，从而能够以具有成本效益的方式进行制造。用CA研究了小柱间距与小柱宽度之比（k=pswt）和小柱与大柱宽度之比（v=wtw）。开发的数学模型能够预测具有与实验制造的分层纹理表面相似的尺寸的水 CA，误差为 6.67%。该模型能够设计和优化各种尺寸的分层纹理表面，从而能够以具有成本效益的方式进行制造。用CA研究了小柱间距与小柱宽度之比（k=pswt）和小柱与大柱宽度之比（v=wtw）。开发的数学模型能够预测具有与实验制造的分层纹理表面相似的尺寸的水 CA，误差为 6.67%。该模型能够设计和优化各种尺寸的分层纹理表面，从而能够以具有成本效益的方式进行制造。