Surfaces designed to reduce the contact time of impacting droplets are potentially of great importance for fundamental science and technological applications, for example, anti-icing, self-cleaning and heating transfer applications. Previous studies have shown that the contact time can be reduced via introducing one or several crossing macroscale wires on superhydrophobic surfaces (SHSs). However, the impacts that strike far from the wires (off-center impacts) have contact times that are equal to those obtained on SHSs. Here we demonstrate that this problem can be largely solved by using macro anisotropic SHSs (macro-aniso-SHSs)—in which the wires are parallel and macroscaled. The droplet contact time depends on the spacing between the macrostripes and is remarkably reduced by 40–50% when the spacing is comparable to the droplet size. Obvious differences in the contact time are not observed for impacts that are centered on the stripe and in the groove. The impacts centered in the groove produce new hydrodynamics that are characterized by extended spreading, easy break up and bouncing in a flying-eagle configuration. The study discusses the underlying mechanisms of the impact processes. Moreover, the effect of parallel wires on the contact time is discussed by comparing the droplet impact data for grooved rice leaves and non-grooved cabbage leaves. The enhanced drop mobility associated with the macro-aniso-SHSs should be very useful in many industrial applications.

设计用于减少撞击液滴接触时间的表面对于基础科学和技术应用（例如防冰，自清洁和热传递应用）具有潜在的重要意义。先前的研究表明，通过在超疏水表面（SHSs）上引入一根或多根交叉的大尺度导线，可以减少接触时间。但是，远离电线的冲击（偏心冲击）的接触时间等于在SHS上获得的接触时间。在这里，我们证明了通过使用宏观各向异性SHS（macro-aniso-SHS），可以在很大程度上解决该问题，在宏观各向异性SHS中，导线是平行的并且是按比例缩放的。液滴的接触时间取决于大条纹之间的间距，当该间距与液滴的大小相当时，其接触时间将显着减少40–50％。对于以条纹和凹槽为中心的冲击，没有观察到明显的接触时间差异。以凹槽为中心的冲击产生了新的流体力学，其特点是扩展的伸展性，易碎的形状以及在飞鹰形态下的弹跳。该研究讨论了影响过程的潜在机制。此外，通过比较带凹槽的稻叶和不带槽的卷心菜叶的液滴冲击数据，讨论了平行线对接触时间的影响。与宏异构SHS相关的增强的墨滴流动性在许多工业应用中应该非常有用。容易分解，并以飞鹰的配置弹跳。该研究讨论了影响过程的潜在机制。此外，通过比较带凹槽的稻叶和不带槽的卷心菜叶的液滴冲击数据，讨论了平行线对接触时间的影响。与宏异构SHS相关的增强的墨滴流动性在许多工业应用中应该非常有用。容易分解，并以飞鹰的配置弹跳。该研究讨论了影响过程的潜在机制。此外，通过比较带凹槽的水稻叶和不带凹槽的卷心菜叶的液滴冲击数据，讨论了平行线对接触时间的影响。与宏异构SHS相关的增强的墨滴流动性在许多工业应用中应该非常有用。