Separation of particles using acoustic streaming and radiation forces in an open microfluidic channel
Separation of particles using acoustic streaming and radiation forces in an open microfluidic channel
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DOI：
10.1007/s10404-014-1380-4
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发表时间：
2014-11-01
影响因子：
2.8
通讯作者：
Neild, Adrian
中科院分区：
文献类型：
--
作者：
Devendran, Citsabehsan;Gralinski, Ian;Neild, Adrian
在这项研究中，展示了一种利用超声波驱动在小样本中根据大小分离颗粒的方法。这是在已经沉积在平面上的流体中实现的，并且被通道容纳，使得它具有矩形的湿润区域。该系统利用声辐射力(ARF)和声流。力场产生了两种稳定的收集位置，一个在液体悬浮介质内，一个在液-气界面上。声流有选择地将较小的颗粒从较低的位置输送到较高的位置。实验数据表明，两组直径分别为3微米和10微米的聚苯乙烯微粒能够分离到不同的稳定位置。还研究了减少较大颗粒向自由表面迁移的方法，从而使分离效率最大化。本文演示了使用手动移液器从初始颗粒混合物中提取液-气界面上的一组99%的纯颗粒。此外，计算模型表明，临界分离尺寸可以通过调节系统的尺寸来调整，以改变对于给定的颗粒尺寸，哪一种ARF和声流诱导的阻力占主导地位，从而提出了一种基于尺寸的可调颗粒分离系统的方法。
In this study, a method to separate particles, within a small sample, based on size is demonstrated using ultrasonic actuation. This is achieved in a fluid, which has been deposited on a flat surface and is contained by a channel, such that it has a rectangular wetted area. The system utilises acoustic radiation forces (ARFs) and acoustic streaming. The force field generates two types of stable collection locations, a lower one within the liquid suspension medium and an upper one at the liquid-air interface. Acoustic streaming selectively delivers smaller particles from the lower locations to the upper ones. Experimental data demonstrate the ability to separate two sets of polystyrene microparticles, with diameters of 3 and 10 mu m, into different stable locations. Methods to reduce migration of larger particles to the free surface are also investigated, thereby maximising the efficiency of the separation. Extraction of one set of 99 % pure particles at the liquid-air interface from the initial particle mixture using a manual pipette is demonstrated here. In addition, computational modelling performed suggests the critical separation size can be tuned by scaling the size of the system to alter which of ARFs and acoustic streaming-induced drag forces is dominant for given particle sizes, therefore presenting an approach to tunable particle separation system based on size.