Department of Bio and Brain Engineering, College of Life Science and Bioengineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
J Chromatogr A. 2011 Jul 8;1218(27):4138-43. doi: 10.1016/j.chroma.2010.11.081. Epub 2010 Dec 5.
We report a contraction-expansion array (CEA) microchannel that allows inertial size separation by a force balance between inertial lift and Dean drag forces in fluid regimes in which inertial fluid effects become significant. An abrupt change of the cross-sectional area of the channel curves fluid streams and produces a similar effect compared to Dean flows in a curved microchannel of constant cross-section, thereby inducing Dean drag forces acting on particles. In addition, the particles are influenced by inertial lift forces throughout the contraction regions. These two forces act in opposite directions each other throughout the CEA microchannel, and their force balancing determines whether the particles cross the channel, following Dean flows. Here we describe the physics and design of the CEA microfluidic device, and demonstrate complete separation of microparticles (polystyrene beads of 4 and 10 μm in diameter) and efficient exchange of the carrier medium while retaining 10 μm beads.
我们报告了一种收缩-扩张阵列（CEA）微通道，该通道允许通过惯性升力和Dean 曳力之间的力平衡进行惯性尺寸分离，在惯性流体效应变得显著的流体状态下。通道的横截面面积的突然变化使流体流弯曲，并产生与具有恒定横截面的弯曲微通道中的 Dean 流相似的效果，从而诱导作用在颗粒上的 Dean 曳力。此外，颗粒在收缩区域受到惯性升力的影响。这两个力在整个 CEA 微通道中彼此反向作用，它们的力平衡决定了颗粒是否沿 Dean 流穿过通道。在这里，我们描述了 CEA 微流控装置的物理原理和设计，并展示了完全分离微颗粒（直径为 4 和 10 μm 的聚苯乙烯珠）和有效交换载流介质，同时保留 10 μm 珠。
