Deterministic Microfluidic Ratchet
Deterministic Microfluidic Ratchet
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DOI：
10.1103/physrevlett.102.045301
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发表时间：
2009-01-30
影响因子：
8.6
通讯作者：
Sturm, James C.
中科院分区：
文献类型：
--
作者：
Loutherback, Kevin;Puchalla, Jason;Sturm, James C.
我们提出了一种确定性的非热棘轮，其中当压力梯度的符号在低雷诺数下反转时，一定尺寸范围内的颗粒的轨迹是不可逆的。这种效果是通过在阵列中采用三角形而不是传统的圆形柱来产生的，选择性地移动通过阵列传输的颗粒。棘轮在与振荡流正交的方向上不可逆地移动一定尺寸范围的颗粒，而流体本身没有净位移。该棘轮的基本机制被证明与不可逆的粒子-柱相互作用以及通过三角形柱之间的间隙的不对称流体速度分布有关。扩散在此棘轮中不起任何作用，因此此处介绍的设备参数可以放大到高流速，这在分离技术中具有明显的重要性。
We present a deterministic, nonthermal ratchet where the trajectory of particles in a certain size range is not reversible when the sign of the pressure gradient is reversed at a low Reynolds number. This effect is produced by employing triangular rather than the conventional circular posts in an array that selectively displaces particles transported through the array. The ratchet irreversibly moves particles of a certain size range in a direction orthogonal to an oscillating flow, with no net displacement of the fluid itself. The underlying mechanism of this ratchet is shown to be connected to irreversible particle-post interactions and the asymmetric fluid velocity distribution through the gap between the triangular posts. Diffusion plays no role in this ratchet, and hence the device parameters presented here can be scaled up to high rates of flow, of clear importance in separation technologies.