Electrothermally modulated contact line dynamics of a binary fluid in a patterned fluidic; environment
Electrothermally modulated contact line dynamics of a binary fluid in a patterned fluidic; environment
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DOI：
10.1063/1.5044268
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发表时间：
2018-09-01
影响因子：
4.6
通讯作者：
Chakraborty, Suman
中科院分区：
文献类型：
--
作者：
Kunti, Golak;Mondal, Pranab Kumar;Chakraborty, Suman
在本文中，我们描述了两种不相容流体在微通道中的界面电热化学流体动力学。二元流体的运动由交流电热(ACET)机制设定。基于自由能相场理论的研究表明，毛细填充动力学和接触线运动是图案化肋条润湿特性和几何参数的强函数。这些参数的调制改变了肋面上的表面能，进而促进了界面张力和驱动电热力之间的相互作用。这两种力的相互作用可能会加速或减慢肋面上的流体-流体-固体接触线的运动。在肋骨的边缘，由于接触线钉扎，界面可能暂停足够长的时间。电极对之间肋条位置的改变改变了电场强度，从而改变了接触线上的整体ACET力。此外，通过适当地布置这些肋片，可以在短距离内获得各种复杂形状的液体锋面，这对于微尺度流动的形态控制具有重要意义。由AIP出版公司出版。
In this paper, we depict the interfacial electro-thermo-chemical-hydrodynamics of two immiscible fluids in a microchannel with substrates patterned by ribs. The motion of the binary fluids is set by an alternating current electrothermal (ACET) mechanism. Our investigation, based on the free-energy-based phase field formalism, reveals that the capillary filling dynamics and the contact line motion are strong functions of the wetting characteristics and geometric parameters of the patterned ribs. Modulation of these parameters alters the surface energy over the rib surface, which, in turn, facilitates the interaction between the interfacial tension and the driving electrothermal force. An interplay of these two forces may speed up or slow down the fluid-fluid-solid contact line motion over the rib surface. At the edges of the ribs, the interface can halt for a sufficiently long time owing to the contact line pinning. Alteration in the position of the ribs between the electrode pairs changes the electric field strength and thereby the bulk ACET forces across the contact line. Furthermore, by suitable arrangement of these ribs, various intricate shapes of the liquid front can be achieved over a short distance, which can have significant implications on the morphological control of microscale flow. Published by AIP Publishing.