Acoustic focusing with engineered node locations for high-performance microfluidic particle separation
Acoustic focusing with engineered node locations for high-performance microfluidic particle separation
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DOI：
10.1039/c4an00034j
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发表时间：
2014-01-01
期刊：
影响因子：
4.2
通讯作者：
Shusteff, Maxim
中科院分区：
文献类型：
--
作者：
Fong, Erika J.;Johnston, Amanda C.;Shusteff, Maxim
用于操纵流体中微粒的声流控装置由于其温和且高速地分选细胞级物体的能力而对生物样品处理很有吸引力。此类装置通常限于将颗粒移向流体通道宽度的整数部分（1/2、1/4、1/6等）的位置。在这项工作中，我们引入了一种独特的声泳装置设计方法，克服了这一限制，使我们能够设计微通道内任何位置的粒子聚焦位置。这是通过制造与样品通道平行的第二流体通道来实现的，第二流体通道通过薄硅壁与其分开。两个通道中的流体参与产生超声共振，而只有一个通道处理样本，从而消除流体和声学边界的耦合。壁的布置和相邻通道的相对宽度限定了粒子聚焦位置。我们研究了一系列此类设备的操作特性，以确定能够实现有效粒子聚焦和分离的配置。结果表明，与没有壁的单个通道相比，足够薄的壁对聚焦效率和位置的影响可以忽略不计，验证了这种设计方法的成功，且不影响分离性能。利用这些原理设计和制造优化的设备配置，我们展示了微球的高效聚焦，以及从哺乳动物细胞中分离无细胞病毒。这些“透明壁”声学装置能够以 450 μL min(-1) 的流速对 10 mm 微球进行超过 90% 的提取效率，并且能够以 100 μL min(-1) 的流速将细胞（纯度为 98%）与病毒颗粒（70% 纯度）分离。
Acoustofluidic devices for manipulating microparticles in fluids are appealing for biological sample processing due to their gentle and high-speed capability of sorting cell-scale objects. Such devices are generally limited to moving particles toward locations at integer fractions of the fluid channel width (1/2, 1/4, 1/6, etc.). In this work, we introduce a unique approach to acoustophoretic device design that overcomes this constraint, allowing us to design the particle focusing location anywhere within the microchannel. This is achieved by fabricating a second fluid channel in parallel with the sample channel, separated from it by a thin silicon wall. The fluids in both channels participate to create the ultrasound resonance, while only one channel processes the sample, thus de-coupling the fluidic and acoustic boundaries. The wall placement and the relative widths of the adjacent channels define the particle focusing location. We investigate the operating characteristics of a range of these devices to determine the configurations that enable effective particle focusing and separation. The results show that a sufficiently thin wall negligibly affects focusing efficiency and location compared to a single channel without a wall, validating the success of this design approach without compromising separation performance. Using these principles to design and fabricate an optimized device configuration, we demonstrate high-efficiency focusing of microspheres, as well as separation of cell-free viruses from mammalian cells. These "transparent wall" acoustic devices are capable of over 90% extraction efficiency with 10 mm microspheres at 450 mu L min(-1), and of separating cells (98% purity), from viral particles (70% purity) at 100 mu L min(-1).