Wetting morphologies at microstructured surfaces
Wetting morphologies at microstructured surfaces
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DOI：
10.1073/pnas.0407721102
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发表时间：
2005-02-08
影响因子：
11.1
通讯作者：
Lipowsky, R
中科院分区：
文献类型：
--
作者：
Seemann, R;Brinkmann, M;Lipowsky, R
对微结构表面的润湿进行了实验和理论研究。即使是相对简单的表面形貌，如具有矩形横截面的凹槽，也表现出多种不同的润湿形态，如通过原子力显微镜观察到的。这种多态现象是由沿着槽角形成的液体楔和沿着槽边缘的接触线钉扎引起的。一个全局形态图的推导，仅取决于两个系统参数：（i）的深宽比的凹槽的几何形状和（它）的接触角的底层基板材料。对于微流体，最有趣的形状机制涉及延伸的液体细丝，其可以在长度上生长和收缩，而其横截面基本保持恒定。因此，可以改变接触角的任何方法都可以用于切换细丝的长度，如在电润湿的上下文中所证明的。
The wetting of microstructured surfaces is studied both experimentally and theoretically. Even relatively simple surface topographies such as grooves with rectangular cross section exhibit a large variety of different wetting morphologies as observed by atomic force microscopy. This polymorphism arises from liquid wedge formation along the groove corners and from contact line pinning along the groove edges. A global morphology diagram is derived that depends only on two system parameters: (i) the aspect ratio of the groove geometry and (it) The contact angle of the underlying substrate material. For microfluidics, the most interesting shape regimes involve extended liquid filaments, which can grow and shrink in length while their cross section stays essentially constant. Thus, any method by which one can vary the contact angle can be used to switch the length of the filament, as is demonstrated in the context of electrowetting.