Electrowetting-induced morphological transitions of fluid microstructures
Electrowetting-induced morphological transitions of fluid microstructures
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DOI：
10.1063/1.1643771
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发表时间：
2004-02
影响因子：
3.2
通讯作者：
A. Klingner;F. Mugele
中科院分区：
文献类型：
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作者：
A. Klingner;F. Mugele
我们研究了具有亲水条纹的疏水衬底上液滴的形态。我们没有使用化学表面图案，而是利用了电润湿效应(带有条纹电极)。这为通过改变施加的电压从外部控制接触角提供了独特的机会。随着电压的增加，液滴会沿着条纹的方向拉长。在临界体积相关电压之外，它们经历了一阶形态转变为细长的圆柱形，接触线固定在条纹的边缘。这一观察结果证实了[M.Brinkmann和R.LiPowsky，J.Appl.太棒了。92,4296(2002)]，它展示了电润湿在非均质基质润湿研究中的灵活性。最后，我们概述了形态转变在微流控器件中的可能应用
We studied the morphology of liquid droplets on hydrophobic substrates with hydrophilic stripes. Instead of using chemical surface patterning we made use of the electrowetting effect (with striped electrodes). This offers the unique opportunity to externally control the contact angle by varying the applied voltage. Upon increasing the voltage, droplets become elongated along the direction of the stripe. Beyond a critical volume-dependent voltage, they undergo a first order morphological transition to an elongated cylindrical shape with the contact line pinned along the edge of the stripe. This observation both confirms recent theoretical and numerical work by [M. Brinkmann and R. Lipowsky, J. Appl. Phys. 92, 4296 (2002)] and it demonstrates the flexibility of electrowetting for wetting studies with heterogeneous substrates. Finally, we outline possible applications of morphological transitions for microfluidic devices