微通道交流电渗粒子收集位置的确定

Determination of the Accumulated Location of Microparticles Collected by AC Electroosmosis in the Microchannel

为了研究在交变电场作用下,样品中的微观粒子被收集到电极表面固定区域的作用机理,通过聚苯乙烯粒子在微通道内的收集实验,得到了粒子及流体的运动规律;基于交流电场作用机理,对电极表面的电势、通道内的电压、电场分布及流体在通道内的流动过程进行了计算,并用仿真分析进行验证。计算及仿真结果表明,粒子在微电极上的收集位置与实验结果十分吻合,即粒子收集的位置为电极上的固定位置。研究结果为交流电渗粒子收集微通道的设计及相关的粒子收集检测提供了理论与实验基础。

The polystyrene microparticle samples driven by AC electroosmosis （ACEO） in a microchannel was tested and simulated in order to study the phenomena that the microparticles have accumulated at fixed region in the electrodes in microchannels in AC field. The motion of microparticles was observed and measured with the image processing method. Based on the mechanism of AC field, the voltage at the surface of electrode, the distribution of voltage and electric field, and the velocity field of ACEO in the microchannel were calculated theoretically and verified by the simulation. The calculation and simulation results of the position of the microparticles in the microchannel show the good agreement with the experimental ones. That is, the particles are accumulated at the position of electrode surface with a certain distance to the border of the electrode. These results are beneficial to the design of microchannels for the microparticle collection caused by ACEO and the measurement of the microparticles collection technology.