Journal of Northeastern University Natural Science ›› 2019, Vol. 40 ›› Issue (3): 447-451.DOI: 10.12068/j.issn.1005-3026.2019.03.027

• 物理学 • Previous Articles     Next Articles

Analysis and Modeling of Electro-osmosis Based on the Modified Poisson-Boltzmann Equation

HU Sheng, LYU Jiang-tao, SI Guang-yuan   

  1. School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao 066004, China.
  • Received:2018-01-24 Revised:2018-01-24 Online:2019-03-15 Published:2019-03-08
  • Contact: HU Sheng
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Abstract: The ion distribution for different concentrations and applied voltage is studied by modeling the ion distribution in electric double layer(EDL)based on the Poisson-Boltzmann(PB)and modified Poisson-Boltzmann(MPB)equations. The results indicate that some errors exist in the thickness of diffusion in EDL if the applied voltage is more than 0.4V and the ion concentration is less than 10-4mol/L. The simulated electro-osmotic flow by using Debye length is not in agreement with the practical observation result mainly because the Debye-Hückel equation is of linear relationship and not compatible with the calculating electro-osmotic flow under higher voltage conditions. By use of the MPB equation with non-linear characteristics, the maximal electro-osmotic flow generated by two co-planar metal electrodes with the width of 500μm and the gap of 25μm is 1034.31μm/s at ±1V potential with the frequency of 500Hz.

Key words: AC electro-osmosis, electric double layer(EDL), PB equation, MPB equation, finite element method

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