A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Science, 31 Leninsky Prospect, 119071 Moscow, Russia.
Institute of Mechanics, M. V. Lomonosov Moscow State University, 119991 Moscow, Russia.
Phys Rev E. 2017 Sep;96(3-1):033109. doi: 10.1103/PhysRevE.96.033109. Epub 2017 Sep 19.
We consider pressure-driven flows in wide microchannels, and discuss how a transverse shear, generated by misaligned superhydrophobic walls, impacts cross-sectional spreading of Brownian particles. We show that such a transverse shear can induce an advective superdiffusion, which strongly enhances dispersion of particles compared to a normal diffusion, and that maximal cross-sectional spreading corresponds to a crossover between its subballistic and superballistic regimes. This allows us to argue that an advective superdiffusion can be used for boosting dispersion of particles at smaller Péclet numbers compared to known concepts of passive microfluidic mixing. This implies that our superdiffusion scenario allows one efficient mixing of much smaller particles or using much thinner microchannels than methods, which are currently being exploited.
我们研究了宽微通道中的压力驱动流动，并讨论了由错位的超疏水壁产生的横向剪切如何影响布朗粒子的横截面扩展。我们表明，这种横向剪切可以诱导一种平流超扩散，与正常扩散相比，它强烈增强了粒子的分散，并且最大的横截面扩展对应于它的亚弹道和超弹道 regimes 之间的交叉。这使我们能够争辩说，与被动微流混合的已知概念相比，平流超扩散可用于在较小的 Peclet 数下增强粒子的分散。这意味着，与目前正在利用的方法相比，我们的超扩散方案可以有效地混合更小的粒子或使用更薄的微通道。
