Hybrid immersed interface-immersed boundary methods for AC dielectrophoresis
Hybrid immersed interface-immersed boundary methods for AC dielectrophoresis
复制标题
DOI：
10.1016/j.jcp.2014.04.012
复制
发表时间：
2014-08-01
影响因子：
4.1
通讯作者：
Duttaa, Prashanta
中科院分区：
文献类型：
--
作者：
Hossana, Mohammad Robiul;Dillonc, Robert;Duttaa, Prashanta
介电泳是一种非线性电动传输机制，已在许多工程应用中变得流行，包括生物材料、颗粒和生物细胞的操纵、表征和驱动。在本文中，我们提出了一种混合浸入界面-浸入边界方法来研究交流介电泳，其中开发了一种算法来使用实变量公式求解复杂的泊松方程。采用浸入界面法来获得含有悬浮颗粒的流体介质中的交流电场，并采用浸入边界法来计算流体方程和颗粒输运。提出了所提出算法的收敛性以及混合方案与实验结果的验证。本文在计算域中考虑粒子的物理效应，采用麦克斯韦应力张量来计算作用于粒子的介电泳力。因此，本研究消除了点偶极子方法中用于计算介电泳力的近似值。提出了计算介电泳力时麦克斯韦应力张量和点偶极子方法的比较研究。混合方法用于研究使用交流电场的微流体装置中介电泳的物理原理。数值结果表明，通过适当的设计和适当选择施加的电位和频率，可以获得全局电场最小值，以利用负介电泳机制促进多个粒子捕获。我们的数值结果还表明，当施加交流电场时，电中性粒子会形成平行于所施加电场的链，而不管它们的初始方向如何。这种提出的混合数值方案将有助于更好地理解介电泳以及设计和优化微流体装置。 (C) 2014 Elsevier Inc. 保留所有权利。
Dielectrophoresis, a nonlinear electrokinetic transport mechanism, has become popular in many engineering applications including manipulation, characterization and actuation of biomaterials, particles and biological cells. In this paper, we present a hybrid immersed interface-immersed boundary method to study AC dielectrophoresis where an algorithm is developed to solve the complex Poisson equation using a real variable formulation. An immersed interface method is employed to obtain the AC electric field in a fluid media with suspended particles and an immersed boundary method is used for the fluid equations and particle transport. The convergence of the proposed algorithm as well as validation of the hybrid scheme with experimental results is presented. In this paper, the Maxwell stress tensor is used to calculate the dielectrophoretic force acting on particles by considering the physical effect of particles in the computational domain. Thus, this study eliminates the approximations used in point dipole methods for calculating dielectrophoretic force. A comparative study between Maxwell stress tensor and point dipole methods for computing dielectrophoretic forces are presented. The hybrid method is used to investigate the physics of dielectrophoresis in microfluidic devices using an AC electric field. The numerical results show that with proper design and appropriate selection of applied potential and frequency, global electric field minima can be obtained to facilitate multiple particle trapping by exploiting the mechanism of negative dielectrophoresis. Our numerical results also show that electrically neutral particles form a chain parallel to the applied electric field irrespective of their initial orientation when an AC electric field is applied. This proposed hybrid numerical scheme will help to better understand dielectrophoresis and to design and optimize microfluidic devices. (C) 2014 Elsevier Inc. All rights reserved.