EHDマイクロポンプ内流れの数値シミュレーション

抄録

In order to efficiently develop microfluidic devices using electrohydrodynamic (EHD) phenomenon, an appropriate model for the phenomenon and a numerical simulation method for EHD flow in microfluidic devices has been required. In this study, EHD flow in micropumps was modeled and a numerical simulation code based on the model was developed. The numerical simulation code was constructed utilizing an open-source CFD software package OpenFOAM. Numerical simulations were performed using the present numerical simulation code for EHD micropumps developed and experimentally tested by Kazemi, et al. (Journal of Microelectromechanical Systems, Vol.18, No.3 (2009), pp.547-554.), and the simulations were validated by comparing with the experiments. The simulated discharge pressure generated in the micropumps was proportional to both applied voltage and charge density, and the experimental discharge pressure was well reproduced by considering the change of charge density with applied voltage. The electrophoretic mobility was assumed to be constant in the present study. This assumption was discussed based on experimental electric current, and it was shown that the assumption was valid in an applied voltage range where EHD phenomenon was dominant. With increasing applied voltage, the charge density was generated when the average electric field on the electrodes exceeded a threshold, and then the charge density was proportional to the average electric field.