An analytical approach to the effect of finite‐sized end reservoirs on electroosmotic transport through narrow confinements
An analytical approach to the effect of finite‐sized end reservoirs on electroosmotic transport through narrow confinements
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DOI：
10.1002/elps.201000308
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发表时间：
2011-02
期刊：
影响因子：
2.9
通讯作者：
D. Pal;S. Chakraborty
中科院分区：
文献类型：
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作者：
D. Pal;S. Chakraborty
末端储层的存在往往在很大程度上改变了电动驱动小型化装置狭窄流体范围内的电势分布。本文利用Schwarz-Christoffel保角映射分析了末端储层有限尺寸效应对相关电位分布的影响。直接作用在通道上的有效电场由一条校准曲线表示，该曲线总结了关键几何参数（水库与通道的高度和长度比）对电位分布的作用。分析模型进一步扩展，以评估通过通道的流动特性。结果表明，末端储层有限尺寸效应引起的有效电场变化对流动特性的影响比末端储层突然收缩和膨胀效应引起的轴向压力梯度对流动特性的影响更为显著。推导的结果可以进一步应用于小型流体装置的实际设计，使用方便易用的分析工具。
The presence of end reservoirs often alters the electrical potential distributions inside narrow fluidic confinements of electrokinetically actuated miniaturized devices to a significant extent. This paper examines the influence of finite size effect of the end reservoirs on the concerned potential distribution analytically, using the Schwarz–Christoffel conformal mapping. The effective electric field directly acting across the channel is accordingly represented by a calibration curve, which sums up the role of the key geometric parameters (reservoir‐to‐channel height and length ratios) on the potential distribution. The analytical model is further augmented to assess the flow characteristics through the channel. The results indicate that the alterations in the flow characteristics due to alterations in the effective electric field on account of the finite size effects of the end reservoirs can turn out to be significantly more prominent than the corresponding alterations due to the axial pressure gradients induced by the sudden contraction and expansion effects associated with the end reservoirs. The derived results can be further utilized to facilitate the practical design of miniaturized fluidic devices, using conveniently tractable analytical tools.