Biomicrofluidics. 2009 Nov 24;3(4):44110. doi: 10.1063/1.3267095.
Electrokinetic transport of cylindrical cells under dc electric fields in a straight microfluidic channel is experimentally and numerically investigated with emphasis on the dielectrophoretic (DEP) effect on their orientation variations. A two-dimensional multiphysics model, composed of the Navier-Stokes equations for the fluid flow and the Laplace equation for the electric potential defined in an arbitrary Lagrangian-Eulerian framework, is employed to capture the transient electrokinetic motion of cylindrical cells. The numerical predictions of the particle transport are in quantitative agreement with the obtained experimental results, suggesting that the DEP effect should be taken into account to study the electrokinetic transport of cylindrical particles even in a straight microchannel with uniform cross-sectional area. A comprehensive parametric study indicates that cylindrical particles would experience an oscillatory motion under low electric fields. However, they are aligned with their longest axis parallel to the imposed electric field under high electric fields due to the induced DEP effect.
在直微流道中直流电场下圆柱形细胞的电动输运进行了实验和数值研究,重点研究了介电泳(DEP)效应对其取向变化的影响。采用二维多物理模型,由Navier-Stokes 方程描述流体流动,由拉普拉斯方程描述任意拉格朗日-欧拉框架下定义的电势,以捕捉圆柱形细胞的瞬态电动运动。颗粒输运的数值预测与实验结果定量一致,表明即使在具有均匀横截面的直微通道中,也应考虑 DEP 效应来研究圆柱形颗粒的电动输运。全面的参数研究表明,在低电场下,圆柱形颗粒会经历振荡运动。然而,由于诱导的 DEP 效应,它们在高电场下会沿着其最长轴与施加的电场平行排列。