Bazant Martin Z, Squires Todd M
Department of Mathematics and Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Phys Rev Lett. 2004 Feb 13;92(6):066101. doi: 10.1103/PhysRevLett.92.066101. Epub 2004 Feb 10.
We give a general, physical description of "induced-charge electro-osmosis" (ICEO), the nonlinear electrokinetic slip at a polarizable surface, in the context of some new techniques for microfluidic pumping and mixing. ICEO generalizes "ac electro-osmosis" at microelectrode arrays to various di-electric and conducting structures in weak dc or ac electric fields. The basic effect produces microvortices to enhance mixing in microfluidic devices, while various broken symmetries--controlled potential, irregular shape, nonuniform surface properties, and field gradients--can be exploited to produce streaming flows. Although we emphasize the qualitative picture of ICEO, we also briefly describe the mathematical theory (for thin double layers and weak fields) and apply it to a metal cylinder with a dielectric coating in a suddenly applied dc field.
我们结合一些微流控泵送和混合的新技术，对“感应电荷电渗”（ICEO）——可极化表面的非线性电动滑移进行了一般性的物理描述。ICEO将微电极阵列处的“交流电渗”推广到弱直流或交流电场中的各种介电和导电结构。其基本效应会产生微涡旋以增强微流控装置中的混合，同时可以利用各种破缺对称性——可控电势、不规则形状、表面性质不均匀以及场梯度——来产生流动。尽管我们着重于ICEO的定性描述，但我们也简要介绍了数学理论（适用于薄双电层和弱场），并将其应用于在突然施加的直流电场中带有介电涂层的金属圆柱体。
