Westerhausen Christoph, Schnitzler Lukas G, Wendel Dominik, Krzysztoń Rafał, Lächelt Ulrich, Wagner Ernst, Rädler Joachim O, Wixforth Achim
Chair of Experimental Physics I, University of Augsburg, Universitätsstraße 1, 86519 Augsburg, Germany.
Nanosystems Initiative Munich, Schellingstraße 4, 80799 Munich, Germany.
Micromachines (Basel). 2016 Sep 2;7(9):150. doi: 10.3390/mi7090150.
Fifteen years ago, surface acoustic waves (SAW) were found to be able to drive fluids and numerous applications in microfluidics have been developed since. Here, we review the progress made and report on new approaches in setting-up microfluidic, continuous flow acoustic mixing. In a microchannel, chaotic advection is achieved by generation of a SAW driven fluid jet perpendicular to the mean flow direction. Using a high speed video camera and particle image velocimetry, we measure the flow velocities and show that mixing is achieved in a particularly controllable and fast way. The mixing quality is determined as a function of system parameters: SAW power, volume flux and fluid viscosity. Exploring the parameter space of mixing provides a practical guide for acoustic mixing in microchannels and allows for adopting conditions to different solvents, as e.g., required for the generation of nanoscale particles from alcoholic phases. We exemplarily demonstrate the potential of SAW based continuous flow mixing for the production of therapeutic nucleic acid nanoparticles assembled from polymer and lipid solutions.
十五年前，人们发现表面声波（SAW）能够驱动流体，自那时起便开发了众多微流体应用。在此，我们回顾已取得的进展，并报告设置微流体连续流声学混合的新方法。在微通道中，通过产生垂直于平均流动方向的SAW驱动流体射流来实现混沌平流。使用高速摄像机和粒子图像测速技术，我们测量了流速，并表明混合是以一种特别可控且快速的方式实现的。混合质量由系统参数决定：SAW功率、体积通量和流体粘度。探索混合的参数空间为微通道中的声学混合提供了实用指南，并允许针对不同溶剂采用相应条件，例如从醇相生成纳米级颗粒时所需的条件。我们示例性地展示了基于SAW的连续流混合在由聚合物和脂质溶液组装治疗性核酸纳米颗粒生产中的潜力。
