RT - Journal Article T1 - Analytical study of cross stream diffusion for combined electroosmotic and Poiseuille flows in rectangular microchannels: inclusion of EDL effect JF - mdrsjrns YR - 2015 JO - mdrsjrns VO - 15 IS - 4 UR - http://mme.modares.ac.ir/article-15-8079-en.html SP - 167 EP - 176 K1 - Electrokinetics K1 - Micromixer K1 - Mixing Intensity K1 - Scaling Analysis K1 - mass transfer AB - Dissemination of an analyte under the laminar flows plays a major role in measuring and assessment of biological fluids such as sample preparation in the context of microfluidic systems. Due to the development of manufacturing technology in the Lab-on-a-chip devices, the production of rectangular microchannels with finite aspect ratios and micron and submicron sizes has been provided by which the effect of electrokinetic phenomena on concentration distribution will be magnified in these systems. Since the recent researches in this field have overlooked such effects, the present work will be conducted analytically to study the effect of electric double layer on cross stream diffusion of the analyte in the combined electroosmotic and pressure driven flows. Three flow scenarios, the favorable, adverse and zero pressure gradients are analyzed. The results demonstrate that the width of the diffusion region near the top and bottom walls of the microchannel becomes broader with the increase in the Debye length. Also, the results of the scaling analysis reveal the decrease in mixing intensity with increasing the Péclet number based on Helmholtz-Smoluchowski velocity and dimensionless Debye–Hückel parameter. As well, the average scaling exponent of this criterion is a descending function with respect to the thickness of the electric double layer. LA eng UL http://mme.modares.ac.ir/article-15-8079-en.html M3 ER -