Sherbaz Ahmad, Konak Büşra M K, Pezeshkpour Pegah, Di Ventura Barbara, Rapp Bastian E
Laboratory of Process Technology, NeptunLab, Department of Microsystems Engineering (IMTEK), University of Freiburg, 79110 Freiburg im Breisgau, Germany.
Signalling Research Centres BIOSS and CIBSS, Institute of Biology II, Faculty of Biology, University of Freiburg, 79110 Freiburg im Breisgau, Germany.
Micromachines (Basel). 2022 Feb 25;13(3):365. doi: 10.3390/mi13030365.
Deterministic lateral displacement (DLD) is a well-known microfluidic technique for particle separation with high potential for integration into bioreactors for therapeutic applications. Separation is based on the interaction of suspended particles in a liquid flowing through an array of microposts under low Reynolds conditions. This technique has been used previously to separate living cells of different sizes but similar shapes. Here, we present a DLD microchip to separate rod-shaped bacterial cells up to 10 µm from submicron spherical minicells. We designed two microchips with 50 and 25 µm cylindrical posts and spacing of 15 and 2.5 µm, respectively. Soft lithography was used to fabricate polydimethylsiloxane (PDMS) chips, which were assessed at different flow rates for their separation potential. The results showed negligible shear effect on the separation efficiency for both designs. However, the higher flow rates resulted in faster separation. We optimized the geometrical parameters including the shape, size, angle and critical radii of the posts and the width and depth of the channel as well as the number of arrays to achieve separation efficiency as high as 75.5% on a single-stage separation. These results pave the way for high-throughput separation and purification modules with the potential of direct integration into bioreactors.
确定性侧向位移（DLD）是一种著名的微流控技术，用于颗粒分离，在集成到用于治疗应用的生物反应器方面具有很高的潜力。分离基于在低雷诺条件下流经微柱阵列的液体中悬浮颗粒的相互作用。该技术先前已用于分离不同大小但形状相似的活细胞。在此，我们展示了一种DLD微芯片，用于从亚微米球形微细胞中分离出长达10 µm的杆状细菌细胞。我们设计了两种微芯片，分别具有50 µm和25 µm的圆柱形柱，间距分别为15 µm和2.5 µm。采用软光刻技术制造聚二甲基硅氧烷（PDMS）芯片，并在不同流速下评估其分离潜力。结果表明，两种设计对分离效率的剪切效应均可忽略不计。然而，较高的流速导致分离速度更快。我们优化了几何参数，包括柱的形状、尺寸、角度和临界半径，以及通道的宽度和深度以及阵列数量，以在单级分离中实现高达75.5%的分离效率。这些结果为高通量分离和纯化模块铺平了道路，具有直接集成到生物反应器中的潜力。
