Controllable Water Adhesion and Anisotropic Sliding on Patterned Superhydrophobic Surface for Droplet Manipulation

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• 作者：Xiaolong Yang ; Xin Liu ; Yao Lu ; Jinlong Song ; Shuai Huang ; Shining Zhou ; Zhuji Jin ; Wenji Xu
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：April 7, 2016
• 年：2016
• 卷：120
• 期：13
• 页码：7233-7240
• 全文大小：655K
• ISSN：1932-7455

文摘

Superhydrophobic surfaces with hydrophilic patterns have wide applications in biomedical and chemical analysis domains. In this work, a rapid, simple, and top-down micromilling method was proposed for fabricating hydrophilic patterns such as micro dots, line, and circle grooves on superhydrophobic surfaces. This method could be extended to construct various linear patterns on diverse substrates on account of its mechanical material-removal mechanism. Hydrophilic micro dots, line, and circle grooves were milled on the superhydrophobic Al alloy surface. The milled micro dots demonstrate great adhesion toward water droplets without changing the contact angles, whereas the prewetted line grooves exhibit strong anisotropic water adhesion; that is, the resistance force that restricts the droplet from detaching in directions parallel and perpendicular to the grooves is significantly different due to the different stress state of the droplet on the grooves. The adhesion force perpendicular to the groove, together with the sliding resistance that is generated by the milled dot, was investigated through experiments. The results show that the relationship between the adhesion force and the droplet–pattern interfacial widths could be well described using the classical Furmidge equation. This research could possibly be employed in such biomedical and chemical analysis domains as water harvesting, droplet storage, and droplet transport.