Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
Lab Chip. 2016 Mar 21;16(6):992-1001. doi: 10.1039/c5lc01100k. Epub 2016 Feb 8.
Inertial focusing in microfluidic channels has been extensively studied experimentally and theoretically, which has led to various applications including microfluidic separation and enrichment of cells. Inertial lift forces are strongly dependent on the flow velocity profile and the channel cross-sectional shape. However, the channel cross-sections studied have been limited to circles and rectangles. We studied inertial focusing in non-rectangular cross-section channels to manipulate the flow profile and thus the inertial focusing of microparticles. The location and number of focusing positions are analyzed with varying cross-sectional shapes and Reynolds number. We found that the broken symmetry of non-equilateral triangular channels leads to the shifting of focusing positions with varying Reynolds number. Non-rectangular channels have unique mapping of the focusing positions and the corresponding basins of attraction. By connecting channels with different cross-sectional shapes, we were able to manipulate the accessible focusing positions and achieve focusing of microparticles to a single stream with ∼99% purity.
在微流控通道中，惯性聚焦已经得到了广泛的实验和理论研究，这导致了各种应用，包括微流控分离和细胞的富集。惯性升力强烈依赖于流速分布和通道横截面形状。然而，所研究的通道横截面仅限于圆形和矩形。我们研究了非矩形横截面通道中的惯性聚焦，以操纵流型，从而实现微粒子的惯性聚焦。分析了不同横截面形状和雷诺数对聚焦位置的影响。我们发现，非等边三角形通道的非对称断裂导致了聚焦位置随雷诺数的变化而移动。非矩形通道具有独特的聚焦位置映射和相应的吸引域。通过连接具有不同横截面形状的通道，我们能够操纵可访问的聚焦位置，并实现对微粒子的聚焦，纯度达到约 99%。
