Factors affecting particle collection by electro-osmosis in microfluidic systems
Factors affecting particle collection by electro-osmosis in microfluidic systems
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DOI：
10.1002/elps.201300420
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发表时间：
2014-02-01
期刊：
影响因子：
2.9
通讯作者：
Hughes, Michael P.
中科院分区：
文献类型：
--
作者：
Mohtar, Mohd Nazim;Hoettges, Kai F.;Hughes, Michael P.
交流电渗透是一种由于双电层和切向电场之间的相互作用而产生的流体传输现象，已被用于诱导流体运动和浓缩悬浮在流体中的颗粒。与用于捕获粒子的其他现象相比，这提供了许多优点，例如将粒子放置在电极中心而不是边缘；规模优势，数百微米宽的电极可以以相同的速率将分子中的颗粒捕获到细胞中；以及受涡流高度限制的捕集体积，这种现象迄今尚未研究。在本文中，检查了由交流电渗透驱动收集引起的颗粒收集的一系列颗粒浓度、电极间间隙宽度、室高度以及介质粘度和密度。描述了收集行为的模型，其中随着时间的推移颗粒收集由两个过程控制，一个由涡流驱动，另一个由沉降驱动，允许确定涡流驱动收集的最大高度，但也表明捕获如何受到高颗粒浓度和流体速度的限制。结果还表明，粘度而不是密度是决定颗粒捕获行为的重要控制因素。
Alternating-current electro-osmosis, a phenomenon of fluid transport due to the interaction between an electrical double layer and a tangential electric field, has been used both for inducing fluid movement and for the concentration of particles suspended in the fluid. This offers many advantages over other phenomena used to trap particles, such as placing particles at an electrode centre rather than an edge; benefits of scale, where electrodes hundreds of micrometers across can trap particles from the molecules to cells at the same rate; and a trapping volume limited by the vortex height, a phenomenon thus far unstudied. In this paper, the collection of particles due to alternating-current electro-osmosis driven collection is examined for a range of particle concentrations, inter-electrode gap widths, chamber heights and media viscosity and density. A model of collection behaviour is described where particle collection over time is governed by two processes, one driven by the vortices and the other by sedimentation, allowing the determination of the maximum height of vortex-driven collection, but also indicates how trapping is limited by high particle concentrations and fluid velocities. The results also indicate that viscosity, rather than density, is a significant governing factor in determining the trapping behaviour of particles.