Department of Mechanical Engineering, University of Maryland Baltimore County, Baltimore, MD 21250, USA.
Lab Chip. 2010 Mar 21;10(6):734-40. doi: 10.1039/b918213f. Epub 2010 Jan 5.
In this paper we present a numerical and experimental investigation of a chaotic mixer in a microchannel via low frequency switching transverse electroosmotic flow. By applying a low frequency, square-wave electric field to a pair of parallel electrodes placed at the bottom of the channel, a complex 3D spatial and time-dependence flow was generated to stretch and fold the fluid. This significantly enhanced the mixing effect. The mixing mechanism was first investigated by numerical and experimental analysis. The effects of operational parameters such as flow rate, frequency, and amplitude of the applied voltage have also been investigated. It is found that the best mixing performance is achieved when the frequency is around 1 Hz, and the required mixing length is about 1.5 mm for the case of applied electric potential 5 V peak-to-peak and flow rate 75 microL h(-1). The mixing performance was significantly enhanced when the applied electric potential increased or the flow rate of fluids decreased.
本文通过低频切换横向电渗流研究了微通道中混沌混合器。通过在通道底部放置一对平行电极施加低频方波电场，产生了复杂的三维空间和时间相关的流场，从而拉伸和折叠流体。这显著增强了混合效果。首先通过数值和实验分析研究了混合机制。还研究了操作参数（如流速、施加电压的频率和幅值）的影响。结果发现，当频率约为 1 Hz 时，混合效果最佳，施加的电势能峰值为 5 V，流速为 75 μL/h(-1) 时，所需的混合长度约为 1.5mm。当施加的电势增加或流体流速降低时，混合性能得到显著增强。
