Lab‐on‐a‐chip (LOC) technologies can take advantage of sheath flows for particle/cell focusing before sensing or sorting. The integration of focusing with other microscale manipulation techniques (e.g., sorting) creates a trade‐off between the throughput of the device and its performance. Therefore, exploring the effective parameters for cells/particles focusing enables us to improve the desired output of LOC devices. A common configuration for sheath‐assisted focusing is Y junctions, which are parametrically studied in this paper. First, a computational model was developed and validated by comparing it with our experimental results. Using COMSOL Multiphysics modeling, the effects of multiple parameters were studied. These parameters include the sheath flow ratio (sheath flow over total flow), width ratio (width of the sheath inlet over the total width), junction angles, and particle size on the focusing width and the distribution of the particles within the focusing region. Then, the numerical data were used to develop two generalized linear models to predict the focusing width of the particles and the standard deviation of the position of the particles. The results showed that the focusing width is greatly impacted by the sheath flow rate ratio. Further, the standard deviation of the position of the particles, which represents the concentration of the particles, is mostly dependent on the flow rate ratio, width ratio, and particle size. Our results provide a better understanding of how the device geometrical and operational factors affect the position of the particles in the development of high‐performance on‐chip sensing and sorting of both cells and particles.

中文翻译：

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芯片实验室平台上的鞘辅助聚焦微粒


芯片实验室（LOC）技术可以在传感或分选之前利用鞘流进行颗粒/细胞聚焦。聚焦与其他微尺度操纵技术（例如分选）的集成在设备的吞吐量和性能之间建立了权衡。因此，探索细胞/颗粒聚焦的有效参数使我们能够提高 LOC 设备的所需输出。鞘辅助聚焦的常见配置是 Y 形连接，本文对其进行了参数研究。首先，通过与我们的实验结果进行比较，开发并验证了计算模型。使用 COMSOL Multiphysics 建模，研究了多个参数的影响。这些参数包括鞘流比（鞘流与总流量之比）、宽度比（鞘入口宽度与总宽度之比）、连接角、聚焦宽度上的颗粒尺寸以及聚焦区域内颗粒的分布。然后，利用数值数据建立两个广义线性模型来预测颗粒的聚焦宽度和颗粒位置的标准偏差。结果表明，聚焦宽度受鞘流率的影响较大。此外，代表颗粒浓度的颗粒位置的标准偏差主要取决于流量比、宽度比和颗粒尺寸。我们的结果可以更好地理解在细胞和颗粒的高性能片上传感和分选的开发中，设备的几何和操作因素如何影响颗粒的位置。