Vortex-free high-Reynolds deterministic lateral displacement (DLD) via airfoil pillars
Vortex-free high-Reynolds deterministic lateral displacement (DLD) via airfoil pillars
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DOI：
10.1007/s10404-018-2160-3
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发表时间：
2018-12-01
影响因子：
2.8
通讯作者：
Kim, Jong-Hoon
中科院分区：
文献类型：
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作者：
Dincau, Brian M.;Aghilinejad, Arian;Kim, Jong-Hoon
生物样品分析的一个基本步骤是在将生物流体输送到生物传感器之前对生物流体进行提纯、分离或分级。确定性横向位移(DLD)已经证明了基于大小的连续分离许多医学上相关的颗粒和生物体的潜力，例如循环中的肿瘤细胞、红细胞，甚至病毒颗粒。最近，利用更高的流速实现了高通量的DLD分离，但这也导致了随着雷诺数(Re)的增加而改变分离动力学。已观察到DLD器件的临界直径(D-c)随再爬升而减小，并从理论上推测流线压缩和涡旋涌现可能是造成这一现象的原因。然而，这种转变的精确机制很难分离出来，因为在带有圆形柱子的高Re DLD器件中，涡流涌现和流线压缩的耦合性质。为了消除这些影响，我们对具有对称翼柱的DLD设备的性能进行了表征，该设备不会产生高达Re=100的涡流。在演示Re=51时粒子轨迹完全移动的过程中，我们已经表明涡旋效应不是导致D-c移动的主要因素，因此流线演化很可能是主要机制。此外，我们将该装置的性能与具有负15度攻角的旋转柱子的类似装置进行了比较，发现当流线变得高度不对称时，分离效率下降，并且小颗粒的轨迹显示出显著的变化。
One essential step in biosample analysis is the purification, separation, or fractionation of a biofluid prior to transport to the biosensor. Deterministic lateral displacement (DLD) has demonstrated the potential for continuous size-based separation of numerous medically relevant particles and organisms, such as circulating tumor cells, red blood cells, and even viral particles. Recently, high-throughput DLD separation has been demonstrated by utilizing higher flow rates, but this also results in changing separation dynamics as the Reynolds number (Re) increases. It has been observed that the critical diameter (D-c) for a DLD device decreases as Re climbs, and theorized that both streamline compression and vortex emergence may contribute to this phenomenon. The precise mechanism for this shift has been difficult to isolate, however, due to the coupled nature of vortex emergence and streamline compression in high-Re DLD devices with circular pillars. To decouple these effects, we have characterized the performance of a DLD device with symmetric airfoil pillars that do not produce vortices up to Re=100. In demonstrating a complete particle trajectory shift at Re=51, we have shown that vortex effects are not a predominant contributor to this D-c shift, thus streamline evolution is likely to be the primary mechanism. Furthermore, we have compared the performance of this device to a similar device with rotated pillars having a negative 15 degrees angle of attack, and found that separation effectiveness declines as streamlines become highly asymmetric and small particles exhibit significant variation in their trajectories.