Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA 16802, USA.
Lab Chip. 2009 Dec 7;9(23):3354-9. doi: 10.1039/b915113c. Epub 2009 Oct 12.
This work introduces a method of continuous particle separation through standing surface acoustic wave (SSAW)-induced acoustophoresis in a microfluidic channel. Using this SSAW-based method, particles in a continuous laminar flow can be separated based on their volume, density and compressibility. In this work, a mixture of particles of equal density but dissimilar volumes was injected into a microchannel through two side inlets, sandwiching a deionized water sheath flow injected through a central inlet. A one-dimensional SSAW generated by two parallel interdigital transducers (IDTs) was established across the channel, with the channel spanning a single SSAW pressure node located at the channel center. Application of the SSAW induced larger axial acoustic forces on the particles of larger volume, repositioning them closer to the wave pressure node at the center of the channel. Thus particles were laterally moved to different regions of the channel cross-section based on particle volume. The particle separation method presented here is simple and versatile, capable of separating virtually all kinds of particles (regardless of charge/polarization or optical properties) with high separation efficiency and low power consumption.
这项工作介绍了一种通过在微流道中利用驻波表面声波（SSAW）诱导声致流来实现连续粒子分离的方法。使用这种基于 SSAW 的方法，可以根据粒子的体积、密度和可压缩性对连续层流中的粒子进行分离。在这项工作中，将相等密度但不同体积的粒子混合物通过两个侧入口注入微通道，中间入口注入去离子水鞘流。通过两个平行的叉指换能器（IDT）在通道中建立了一维 SSAW，通道跨越位于通道中心的单个 SSAW 压力节点。SSAW 的应用对较大体积的粒子产生了更大的轴向声力，将它们重新定位到更接近通道中心的波压力节点。因此，根据粒子体积，粒子被横向移动到通道横截面的不同区域。这里提出的粒子分离方法简单且通用，能够以高效率和低功耗分离几乎所有种类的粒子（无论其电荷/极化或光学性质如何）。
