Electric generation and ratcheted transport of contact-charged drops
Electric generation and ratcheted transport of contact-charged drops
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DOI：
10.1103/physreve.96.043101
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发表时间：
2017-10-02
影响因子：
2.4
通讯作者：
Bishop, Kyle J. M.
中科院分区：
文献类型：
--
作者：
Cartier, Charles A.;Graybill, Jason R.;Bishop, Kyle J. M.
我们描述了一个简单的微流控系统，使稳定的生产和有效的运输的水滴只使用一个恒定的电压输入。液滴的产生是通过电流体动力学滴落机制来实现的，通过该机制，导电液滴响应于电场而生长并从接地喷嘴分离。现在充电的液滴通过接触电荷电泳沿棘轮通道向下输送，接触电荷电泳由用于液滴生成的相同电压输入供电。我们调查如何滴的大小，产生频率和运输速度取决于系统参数，如液体粘度，界面张力，施加电压，和通道尺寸。所观察到的趋势很好地解释了一系列的缩放分析，提供了深入了解的占主导地位的物理机制的基础下降的生成和棘轮运输。我们确定了实现可靠运行所需的条件，并讨论了违反这些条件时可能出现的各种故障模式。我们的研究结果表明，简单的电输入可以为日益复杂的液滴操作提供动力，这为廉价和便携式微流体系统提供了潜在的机会。
We describe a simple microfluidic system that enables the steady generation and efficient transport of aqueous drops using only a constant voltage input. Drop generation is achieved through an electrohydrodynamic dripping mechanism by which conductive drops grow and detach from a grounded nozzle in response to an electric field. The now-charged drops are transported down a ratcheted channel by contact charge electrophoresis powered by the same voltage input used for drop generation. We investigate how the drop size, generation frequency, and transport velocity depend on system parameters such as the liquid viscosity, interfacial tension, applied voltage, and channel dimensions. The observed trends are well explained by a series of scaling analyses that provide insight into the dominant physical mechanisms underlying drop generation and ratcheted transport. We identify the conditions necessary for achieving reliable operation and discuss the various modes of failure that can arise when these conditions are violated. Our results demonstrate that simple electric inputs can power increasingly complex droplet operations with potential opportunities for inexpensive and portable microfluidic systems.