Deterministic lateral displacement (DLD) is a microfluidic technique for size fractionation of particles/cells in continuous flow with a great potential for biological and clinical applications. Growing interest of DLD devices in enabling high-throughput operation for practical applications, such as circulating tumor cell (CTC) separation, necessitates employing higher flow rates, leading to operation at moderate to high Reynolds number (Re) regimes. Recently, it has been shown that symmetric airfoil shaped pillars with neutral angle-of-attack (AoA) can be used for high-throughput design of DLD devices due to their mitigation of vortex effects and preservation of flow symmetry under high Re conditions. While high-Re operation with symmetric airfoil shaped pillars has been established, the effect of AoAs on the DLD performance has not been investigated. In this paper, we have characterized the airfoil DLD device with various AoAs. The transport behavior of microparticles has been observed and analyzed with various AoAs in realistic high-Re. Furthermore, we have modeled the flow fields and anisotropy in a representative airfoil pillar array, for both positive and negative AoA configurations. Unlike the conventional DLD device, lateral displacement has been suppressed with +5° and + 15° AoA configurations regardless of particle sizes. On the other hand, stronger lateral displacement has been seen with −5° and − 15° AoAs. This can be attributed to growing flow anisotropy as Re climbs, and significant expansion or compression of streamlines between airfoils with AoAs. The findings in this study can be utilized for the design and optimization of airfoil DLD microfluidic devices with various AoAs.

中文翻译：

---

攻角对对称翼型立柱的确定性横向位移（DLD）的影响。

确定性横向位移（DLD）是一种微流体技术，用于连续流动中的颗粒/细胞尺寸分级，具有很大的生物学和临床应用潜力。DLD设备越来越关注在实际应用中实现高通量操作（例如循环肿瘤细胞（CTC）分离）的必要性，因此必须采用更高的流速，从而可以在中等至高的雷诺数下操作（Re）制度。近来，已经证明具有中性攻角（AoA）的对称翼型柱可用于DLD设备的高通量设计，因为它们可减轻涡流效应并在高Re条件下保持流动对称性。虽然已经建立了具有对称翼型形支柱的高Re操作，但尚未研究AoA对DLD性能的影响。在本文中，我们对具有各种AoA的机翼DLD设备进行了表征。在现实的高分辨率下，已经用各种AoA观察和分析了微粒的传输行为。此外，对于正和负AoA配置，我们已经对代表性翼型柱阵列中的流场和各向异性建模。与传统的DLD设备不同，+ 5°和+ 15°AoA配置可抑制横向位移，而与颗粒大小无关。另一方面，在-5°和-15°A​​oAs下观察到更强的横向位移。这可以归因于流动各向异性的增加，因为再次爬升，以及带有AoA的机翼之间流线的显着扩展或压缩。这项研究中的发现可用于设计和优化具有各种AoA的机翼DLD微流控设备。