Heng Xin, Luo Cheng
Department of Mechanical and Aerospace Engineering, University of Texas at Arlington , 500 West First Street, Woolf Hall 226, Arlington, Texas 76019, United States.
Langmuir. 2015 Mar 10;31(9):2743-8. doi: 10.1021/la504566r. Epub 2015 Feb 27.
We have recently observed an interesting phenomenon: even under gravity, a microliter-scaled silicone oil drop was still able to run upward between two nonparallel plates that were approximately vertically placed. We also saw the same phenomenon in the case of isopropyl alcohol (IPA) drops. In this work, we developed simple models to interpret this phenomenon, followed by experimental validation. We demonstrated that, by changing the locations of drops or tilt and opening angles of plates, the moving directions of silicone oil, IPA, and water drops could be controlled. In the cases of silicone oil and IPA, we also found that the speed of a drop had a linear relation with the square of the drop location when the drop was far away from the corner of two nonparallel plates and that the drop moved faster as it became closer to this corner.
即使在重力作用下，微升尺度的硅油滴仍能够在近似垂直放置的两个非平行板之间向上移动。在异丙醇（IPA）滴的情况下，我们也观察到了同样的现象。在这项工作中，我们开发了简单的模型来解释这一现象，随后进行了实验验证。我们证明，通过改变液滴的位置或平板的倾斜角度和开口角度，可以控制硅油、IPA和水滴的移动方向。在硅油和IPA的情况下，我们还发现，当液滴远离两个非平行板的角落时，液滴的速度与液滴位置的平方呈线性关系，并且液滴越靠近这个角落移动得越快。
