Physics of Interfaces and Nanomaterials, MESA+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands.
Langmuir. 2011 Sep 6;27(17):11238-45. doi: 10.1021/la201671w. Epub 2011 Aug 9.
The motion of droplets under the influence of lithographically created anisotropic chemically defined patterns is described and discussed. The patterns employed in our experiments consist of stripes of alternating wettability: hydrophobic stripes are created via fluorinated self-assembled monolayers, and for hydrophilic stripes, the SiO(2) substrate is used. The energy gradient required to induce the motion of the droplets is created by varying the relative widths of the stripes in such a way that the fraction of the hydrophilic area increases. The anisotropic patterns create a preferential direction for liquid spreading parallel to the stripes and confine motion to the perpendicular direction, giving rise to markedly higher velocities as compared to nonstructured surface energy gradients. Consequently, the influence of the distinct pattern features on the overall motion as well as suggestions for design improvements from an application point of view are discussed.
本文描述并讨论了在光刻产生的各向异性化学定义图案影响下液滴的运动。我们实验中采用的图案由交替润湿性的条纹组成：通过氟化自组装单层形成疏水性条纹，而对于亲水性条纹，则使用 SiO2 基底。通过改变条纹的相对宽度来产生诱导液滴运动所需的能量梯度，使得亲水区的比例增加。各向异性图案在平行于条纹的方向上产生液体扩展的优先方向，并将运动限制在垂直方向，从而产生比非结构化表面能梯度显著更高的速度。因此，本文从应用的角度讨论了不同图案特征对整体运动的影响以及设计改进的建议。
