We propose a micromixer for obtaining better efficiency of vortex induced electroosmotic mixing of non-Newtonian bio-fluids at a relatively higher flow rate, which finds relevance in many biomedical and biological applications. To represent the rheology of non-Newtonian fluid, we consider the Carreau model in this study, while the applied electric field drives the constituent components in the micromixer. We show that the spatial variation of the applied field, triggered by the topological change of the bounding surfaces, upon interacting with the non-uniform surface potential gives rise to efficient mixing as realized by the formation of vortices in the proposed micromixer. Also, we show that the phase-lag between surface potential leads to the formation of asymmetric vortices. This behavior offers better mixing performance following the appearance of undulation on the flow pattern. Finally, we establish that the assumption of a point charge in the paradigm of electroosmotic mixing, which is not realistic as well, under-predicts the mixing efficiency at higher amplitude of the non-uniform zeta potential. The inferences of the present analysis may guide as a design tool for micromixer where rheological properties of the fluid and flow actuation parameters can be simultaneously tuned to obtain phenomenal enhancement in mixing efficiency.

中文翻译：

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非均匀带电波浪微通道中非牛顿生物流体涡旋诱导电渗混合的数值研究：有限离子尺寸的影响

我们提出了一种微混合器，用于在相对较高的流速下获得更好的涡流诱导电渗混合非牛顿生物流体的效率，这在许多生物医学和生物学应用中具有相关性。为了表示非牛顿流体的流变学，我们在本研究中考虑了 Carreau 模型，而施加的电场驱动微混合器中的组成组件。我们表明，由边界表面的拓扑变化触发的施加场的空间变化在与非均匀表面电位相互作用时会产生有效的混合，正如在所提出的微混合器中形成涡流所实现的那样。此外，我们表明表面电位之间的相位滞后导致不对称涡旋的形成。在流动模式出现波动后，这种行为提供了更好的混合性能。最后，我们确定电渗混合范式中的点电荷假设（这也是不现实的）低估了在非均匀 zeta 电位的较高幅度下的混合效率。本分析的推论可以作为微混合器的设计工具提供指导，其中可以同时调整流体的流变特性和流动驱动参数，从而显着提高混合效率。