Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran.
Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran; Stem Cell and Regenerative Medicine Center, Sharif University of Technology, Tehran, Iran.
J Chromatogr A. 2024 Nov 8;1736:465397. doi: 10.1016/j.chroma.2024.465397. Epub 2024 Sep 25.
In conventional Deterministic Lateral Displacement (DLD), the migration behavior of a particle of specific size is determined by the critical diameter (D), which is predefined by the device's geometry. In contrast to the typical approach that alters the angle between the pillar array and fluid streamlines by modifying the geometrical parameters, this study introduces a novel perspective that focuses on changing the direction of the streamlines. The proposed technique offers a tunable DLD chip featuring a straightforward design that allows for easy fabrication. This chip features one completely horizontal pillar array with two bypass channels on the top and bottom of the DLD chamber. The width of these bypass channels changes linearly from their inlet to their outlet. Two design configurations are suggested for this chip, characterized by either parallel or unparallel slopes of the bypass channels. This chip is capable of generating a wide range of D values by manipulating two distinct control parameters. The first control parameter involves adjusting the flow rates in the two bypass channels. The second control parameter entails controlling the slopes of these bypass channels. Both of these parameters influence the direction of particle-carrying streamlines resulting in a change in the path-line of the particles. By changing the angle of streamlines with pillar array, the D can be tuned. Prior to determining the D for each case, an initial estimation was made using a Python script that utilized the streamline coordinates. Subsequently, through FEM modeling of the particle trajectories, precise D values were ascertained and compared with the estimated values, revealing minimal disparities. By adjusting the flow rate and slope of the bypass channels, maximum D ranges of 4-10 μm and 8-13 μm can be achieved, respectively. This innovative chip enables the attainment of D values spanning from 0.5 to 14 μm.
在传统的确定性横向位移（DLD）中，特定尺寸颗粒的迁移行为由临界直径（D）决定，而 D 由器件的几何形状预先定义。与通过改变柱状阵列和流体流线之间的角度来改变几何参数的典型方法不同，本研究提出了一种新的方法，侧重于改变流线的方向。该技术提供了一种可调谐的 DLD 芯片，其设计简单，易于制造。该芯片具有一个完全水平的柱状阵列，在 DLD 腔室的顶部和底部有两个旁路通道。这些旁路通道的宽度从入口到出口呈线性变化。该芯片有两种设计配置，其旁路通道的斜率要么是平行的，要么是不平行的。通过操纵两个不同的控制参数，该芯片可以产生广泛的 D 值范围。第一个控制参数涉及调整两个旁路通道中的流速。第二个控制参数涉及控制这些旁路通道的斜率。这两个参数都影响携带颗粒的流线的方向，从而改变颗粒的路径。通过改变流线与柱状阵列的角度，可以调整 D。在确定每种情况下的 D 之前，使用一个 Python 脚本利用流线坐标进行了初步估计。然后，通过对颗粒轨迹的有限元建模，确定了精确的 D 值，并与估计值进行了比较，发现差异很小。通过调整旁路通道的流速和斜率，可以分别达到最大 D 值范围为 4-10μm 和 8-13μm。这种创新的芯片可以实现 0.5-14μm 范围内的 D 值。
