基于介电泳的电极阵列电场仿真研究

Simulation of Electric Field for Dielectrophoretic Electrode Arrays

介电泳方法被广泛地应用于微纳颗粒的分离和操纵中,实现介电泳操作的关键是设计满足所需电场分布的电极阵列。针对目前在微电极阵列设计中尚缺乏简单有效的电场解析方法的现状,提出一种基于格林公式的电极阵列电场的解析方法。首先介绍了传统介电泳和行波介电泳的概念和计算模型,分析了介电泳过程与电极上所施加的交变电压的频率和幅度的关系,然后在确立电极电势的边界条件的基础上,采用基于格林公式的电场解析方法,建立了非均匀电场的解析模型,得出不同条件下的电极阵列电场分布的仿真结果,最后利用FEMLAB有限元仿真软件对解析模型进行了对比仿真,验证了该解析模型的可行性。基于格林公式的电场解析求解方法能够有效地提高电极阵列设计中的针对性以及缩短电极设计的时间。

Dielectrophoretic method is widely used in separation and manipulation of micro/nano particles, and the key for realizing the dielectrophoretic manipulation is to design the proper micro electrode arrays to satisfy the required distribution of electric field. Considering the lack of analytical solution of electric filed analysis in the design of electrode arrays, the paper presents an analytical solution based on the Green＇s theorem. The conceptions and calculation models of conventional dielectrophoresis （cDEP） and travelling wave dielectrophoresis（twDEP） are intro-duced, and the relationship between the DEP process and the voltage applied on electrodes is also analyzed. After the boundary condition between electrodes is established, the analytical model of non-uniform electric field based on Green＇s theorem is built and the simulation results under different conditions are derived, and the field distributions so obtained are compared with those calculated by the finite element tool （FEMLAB）. The comparison shows the validity of the analytical solution. The solution based on Green＇s theorem is helpful to improve the pertinence of the design of electrode arrays and shorten the design time.