中文摘要：

基于直流介电泳技术,采用一种具有三维突扩、突缩截面的新型毛细管式微通道,对直径分别为8和12μm的聚苯乙烯微粒在通道中的分离进行数值模拟。分析了微粒受到的电渗力、电泳力和介电泳力对其运动轨迹的影响。数值模拟结果表明,聚苯乙烯微粒在突扩、突缩截面附近受到负介电泳力作用,运动轨迹不断向通道轴心偏移;电渗力和电泳力的作用方向相反,有效降低了微粒的运动速度,增加了介电泳力的作用时间。外加电压100 V时,可最有效地将直径为8μm微粒输运至出口内置套管外,而直径为12μm的微粒被出口内置套管接收,实现不同尺寸聚苯乙烯微粒的连续分离。

英文摘要：

Based on the direct current dielectrophoresis（DC-DEP）,using an novel capillary microchannel with the 3D abrupt convergent-divergent section,the numerical simulations of separation for polystyrene particles with diameters of 8 and12μm in the microchannel were carried out.The effects of the electroosmotic force,electrophoretic force and dielectrohoretic force on the particle trajectories were analyzed.The numerical simulation results show that polystyrene particles are driven by negative DEP force nearby the abrupt convergent-divergent section,the particle trajectory shifts gradually towards the central line of the microchannel.The electroosmotic force and electrophoretic force are in opposite directions to reduce the particle velocity effectively and increase the acting duration of the DEP force.When100 V external voltage was applied,the particles with the diameter of 8μm were perfectly transported to the outside of the inner tube at the outlet,while the particles with the diameter of 12μm were retrieved by the inner tube,and the continuous separation of polystyrene particles with different sizes was achieved.