Enhancing solute dispersion in electrically actuated flows has always been a challenging proposition, as attributed to the inherent uniformity of the flow field in absence of surface patterns. Over the years, researchers have focused their attention towards circumventing this limitation, by employing several fluidic and geometric modulations. However, the corresponding improvements in solute dispersion often turn out to be inconsequential. Here we unveil that by exploiting the interplay between an externally imposed temperature gradient, subsequent electrical charge redistribution and ionic motion, coupled with the rheological complexities of the fluid, one can achieve up to one order of magnitude enhancement of solute dispersion in a pressure-driven flow of an electrolyte solution. Our results demonstrate that the complex coupling between thermal, electrical, hydro-dynamic and rheological parameters over small scales, responsible for such exclusive phenomenon, can be utilitarian in designing novel thermally-actuated micro and bio-microfluidic devices with favorable solute separation and dispersion characteristics.

中文翻译：

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粘弹性微流中温度梯度引起的溶质弥散的大量增加

增强电驱动流中的溶质分散一直是一个具有挑战性的命题，这归因于在没有表面图案的情况下流场的固有均匀性。多年来，研究人员通过采用几种流体和几何调制将注意力集中在规避这一限制上。然而，溶质分散方面的相应改进常常被证明是无关紧要的。在这里，我们揭示了通过利用外部施加的温度梯度、随后的电荷重新分布和离子运动之间的相互作用，再加上流体的流变复杂性，可以在压力驱动下实现溶质分散的一个数量级增强。电解质溶液的流动。我们的结果表明，热、