Dynamics of Morphological Wetting Transitions on Topographic Substrates

我们建议利用各种液体形态形成的拓扑结构的基板上操纵少量的液体在该基板上（开放式微流体）。利用电润湿效应，我们计划通过在自由液体表面的各种平衡形态之间切换，在具有适当台阶和凹槽的衬底上传输液体。形貌基底的特别优点是出现的液体形态的拉普拉斯压力的可变性，使得液体甚至可以从零压力储液器中取出。我们要研究各种参数对液体形态的影响，如施加的（交流）电压，其频率，绝缘衬底涂层的厚度，和衬底的形貌。特别强调的是由于在接触线附近的电场和外部变形，由于在一个凹槽中的限制的表面轮廓的内在变形的相互作用。使用原子力显微镜和共聚焦荧光显微镜观察液体形态。

We propose to exploit the variety of liquid morphologies forming on topographically structured substrates for manipulating small amounts of liquids on that substrate (open microfluidics). Using the electrowetting effect, we plan to transport liquids on a substrate bearing appropriate steps and grooves, by switching between various equilibrium morphologies of the free liquid surface. The particular advantage of topographic substrates is the variability in the Laplace pressure of the emerging liquid morphologies, such that liquid may be taken even from a zero pressure reservoir. We want to study the impact of a variety of parameters on the liquid morphologies, such as the applied (ac-) voltage, its frequency, the thickness of the insulating substrate coating, and the topography of the substrate. Particular emphasis will be on the interplay of the intrinsic deformation of the surface profile due to electric fields in the vicinity of the contact line and the external deformation due to the confinement in a groove. The liquid morphologies will be observed using atomic force microscopy and confocal fluorescence microscopy.