DC-biased AC-electroosmotic and AC-electrothermal flow mixing in microchannels
DC-biased AC-electroosmotic and AC-electrothermal flow mixing in microchannels
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DOI：
10.1039/b813639d
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发表时间：
2009-01-01
期刊：
影响因子：
6.1
通讯作者：
Rodriguez, Isabel
中科院分区：
文献类型：
--
作者：
Ng, Wee Yang;Goh, Shireen;Rodriguez, Isabel
本文提出了一种在微通道中混合两种层流流的新方法。所述混合器包括沿流体通道布置的一对电极。通过用直流偏置（2.5 V）交流电压（20 V(pp)）给电极通电，产生一种垂直于待混合液体层流的流型的电动流动。因此，来流和诱导流的流线被迫交叉，可以在短的混合长度下实现非常有效的搅拌和混合。混合器可以从交流电渗透（ACEO） （sigma = 1 mS/m, f = 100 kHz）到交流电热（ACET） （sigma = 500 mS/m, f = 500 kHz）流动模式操作。ACEO模式下的混合效率为92%，混合长度为600 mm (Q = 2 μ L/min)，估计混合时间为69 ms，诱导ACEO流速为725 μ m/s。ACET的混合效率为65%，混合长度约为1200 μ m。该混合器效率高，适用于各种微流体应用中从低到高电导率的流体介质中混合试剂。
This paper presents a novel approach of mixing two laminar flowing streams in microchannels. The mixer consists of a pair of electrodes disposed along a fluidic channel. By energizing the electrodes with a DC-biased (2.5 V) AC voltage (20 V(pp)), an electrokinetic flow is induced with a flow profile perpendicular to that of the incoming laminar streams of liquids to be mixed. As a result, the flow lines of the incoming streams and the induced flow are forced to crossover and very efficient stirring and mixing at short mixing length can be achieved. The mixer can be operated from the AC-electroosmotic (ACEO) (sigma = 1 mS/m, f = 100 kHz) to the AC-electrothermal (ACET) (sigma = 500 mS/m, f = 500 kHz) flow regimes. The mixing efficiency in the ACEO regime was 92%, with a mixing length of 600 mm (Q = 2 mu L/min), an estimated mixing time of 69 ms and an induced ACEO flow velocity of similar to 725 mu m/s. The mixing efficiency in the ACET regime was 65% for a mixing length of similar to 1200 mu m. The mixer is efficient and suitable for mixing reagents in a fluid media from low to high conductivity as required in diverse microfluidic applications.