Microfluidic chips integrated with negative dielectrophoresis (nDEP) and electrochemical impedance spectroscopy have wide applications in cell sensing. Accurate analysis of the kinematics and dynamics of cells in the nDEP process is crucial to improve the positioning accuracy and electric cell-substrate impedance sensing (ECIS) performance. This paper reports employing the three-dimensional (3D) finite element model to analyze the coupling effects of electrokinetic flows (EF) such as alternating current electroosmosis (ACEO) and the electrothermal flow (ETF) on the nDEP positionings. On the quadrupole ECIS microfluid chip, three typical nDEP results are observed in the frequency range of 100 Hz-25 MHz and the amplitude range of 1-20 V_p-p. Simulations Based on the 3D hybrid model provide abundant kinematic information and show clear dynamic processes. Based on the discussion, the mechanisms of nDEP localizations and phase-tuning manipulations are proposed. It is found that the drag force could affect the particle's movement through the vortex of the flow field induced by ACEO and ETF, while the nDEP forces dominate the particles' locations on the substrate. Thus, the 3D dynamic-coupling analyses could help design the quadrupole-electrode microfluid chip and optimize the manipulation parameters in the experiment.

集成了负介电电泳（nDEP）和电化学阻抗谱的微流控芯片在细胞传感中具有广泛的应用。在nDEP过程中，对电池的运动学和动力学进行准确的分析对于提高定位精度和电池-基板阻抗感测（ECIS）电性能至关重要。本文报告使用三维（3D）有限元模型来分析电动流（EF）的耦合效应，例如交流电渗（ACEO）和电热流（ETF）对nDEP位置的影响。在四极ECIS微流体芯片上，在100 Hz-25 MHz的频率范围和1-20 V _p-p的幅度范围内观察到三个典型的nDEP结果。基于3D混合模型的仿真可提供丰富的运动信息，并显示清晰的动态过程。在此基础上，提出了nDEP定位和相位调整操作的机制。发现拖曳力可能会影响粒子通过ACEO和ETF诱导的流场涡流的运动，而nDEP力则控制粒子在基质上的位置。因此，3D动态耦合分析可以帮助设计四极电极微流体芯片并优化实验中的操纵参数。