Torino S, Iodice M, Rendina I, Coppola G, Schonbrun E
Institute for Microelectronics and Microsystems , National Research Council, Naples, Italy.
Rowland Institute at Harvard, Harvard University , 100 E. Land Blvd., Cambridge, Massachusetts 02142, USA.
Biomicrofluidics. 2015 Nov 20;9(6):064107. doi: 10.1063/1.4936260. eCollection 2015 Nov.
The flow focusing is a fundamental prior step in order to sort, analyze, and detect particles or cells. The standard hydrodynamic approach requires two fluids to be injected into the microfluidic device: one containing the sample and the other one, called the sheath fluid, allows squeezing the sample fluid into a narrow stream. The major drawback of this approach is the high complexity of the layout for microfluidic devices when parallel streams are required. In this work, we present a novel parallelized microfluidic device that enables hydrodynamic focusing in each microchannel using a single feed flow. At each of the parallel channels, a cross-filter region is present that allows removing fluid from the sample fluid. This fluid is used to create local sheath fluids that hydrodynamically pinch the sample fluid. The great advantage of the proposed device is that, since only one inlet is needed, multiple parallel micro-channels can be easily introduced into the design. In the paper, the design method is described and the numerical simulations performed to define the optimal design are summarized. Moreover, the operational functionality of devices tested by using both polystyrene beads and Acute Lymphoid Leukemia cells are shown.
为了对颗粒或细胞进行分选、分析和检测，流动聚焦是一个基本的前期步骤。标准的流体动力学方法需要将两种流体注入微流控装置：一种包含样品，另一种称为鞘液，用于将样品流体挤压成狭窄的流束。这种方法的主要缺点是，当需要平行流时，微流控装置的布局非常复杂。在这项工作中，我们提出了一种新型的并行微流控装置，该装置能够使用单一进料流在每个微通道中实现流体动力学聚焦。在每个平行通道处，都有一个交叉过滤区域，用于从样品流体中去除流体。这些流体用于创建局部鞘液，从而在流体动力学上挤压样品流体。所提出的装置的巨大优势在于，由于只需要一个入口，因此可以很容易地在设计中引入多个平行微通道。本文描述了设计方法，并总结了为确定最佳设计而进行的数值模拟。此外，还展示了使用聚苯乙烯珠和急性淋巴细胞白血病细胞对装置进行测试的操作功能。
