Journal of Applied Sciences1812-56541812-5662Asian Network for Scientific Information10.3923/jas.2008.1632.1641LuoW.J. ChangK.C. WangJ.S. 9200889This research demonstrates the mixing of two-dimensional, time-dependent elestro-osmotic flows in a T-shaped microchannel via the application of a rectified AC electric field at one inlet channel and a DC electric field at the other. By specifying appropriate electric field intensities at the two inlets, a momentum imbalance is induced at the interface between the two fluid streams. This imbalance prompts the formation of a periodic waveform at the interface, which propagates in the downstream direction, resulting in an enhanced mixing of the two species. The characteristics of the micromixer are investigated by performing a series of numerical simulations using the backwards-Euler time-stepping scheme. The results show that the relative proportion of the two fluid streams entering the mixing channel can be adjusted by regulating the difference in intensity of the two electric fields. For a given AC electric field, two threshold values of the DC electric field intensity are found, corresponding to fully-mixed dimensionless concentrations of zero (upper inlet fluid only) and one (lower inlet fluid only), respectively. The dimensionless concentration obtained at DC intensities between these two threshold values varies linearly with the difference in intensity of the two electric fields, but is independent of the frequency of the AC electric field. Finally, varying the width of the mixing channel has no significant effect on the mixing performance (provided that the mixing length is adequately extended) and results in no more than a minor expansion of the linear range bounded by the two DC voltage threshold values.]]>Ajdari, A.,199575755758Biddiss, E., D. Erickson and D. Li,20047632083213Branerbjerg, J., P. Gravesen, J.P. Krog and C.R. Nielsen,199659177182Chang, C.C. and R.J. Yang,200414550558Chen, J.K., W.J. Luo and R.J. Yang,20064579837990Dutta, P. and A. Beskok,20017350975102Erickson, D. and D. Li,20021818831892Hunter, R.J.,1986Lee, Y.K., J. Deval, P. Tabeling and C.M. Ho,20012001pp: 483486Lu, L.H., K.S. Ryu and C. Liu,200211462469Luo, W.J.,2004278497507Luo, W.J. and R.J. Yang,20042095105Luo, W.J., Y.J. Pan and R.J. Yang,200515463473Luo, W.J.,2006295551561Luo, W.J., K.F. Yarn and S.P. Hsu,20074616081616Luo, W.J., K.C. Chang, K.F. Yarn and M.H. Shih,2007Luo, W.J., K.F. Yarn, M.H. Shih and K.C. Yu,20082117125Mengeaud, V., J. Josserand and H.H. Girault,20027442794286Miyake, R., T.S.J. Lammerink, M. Elwenspoek and J.H.J. Fluitman,19931993pp: 248253Oddy, M.H., J.G. Santiago and J.C. Mikkelsen,20017358225832Qian, S. and H.H. Bau,20027436163625Rife, J.C., M.I. Bell, J.S. Horwitz, M.N. Kabler, R.C.Y. Kabler, R.C.Y. Auyeung and W.J. Kim,200086135140Voldman, J., M.L. Gray and M.A. Schmidt,20009295302Yang, C. and D. Li,1998143339353Yang, R.J. and W.J. Luo,200216115131Yang, R.J., C.H. Wu, T.I. Tseng and G.B. Lee,20054476347642