Analytical and Numerical Investigations of Electrokinetic Micromixing in Electroosmotic Micromixers

Abstract

Improvement in mixing quality under of low Reynolds number hydrodynamic flows in microchannel devices is mandatory and essential. This paper investigates the electrokinetic effects on mixing of two miscible fluid streams (ethanol and water) in two different micromixers (i.e., circular and square micromixers) with the help of analytical, semianalytical, and numerical methods. In the analytical method, we develop a closed form solution in order to evaluate normalized electric potential distribution as a function of normalized microchannel channel width, as well as a semianalytical solution for normalized concentration distribution across the normalized microchannel width. In addition, in the context of the numerical method (based on the Finite Element Method approach), we perform a parametric study by varying the input AC voltage and compare the extent of mixing in the two proposed micromixers. Moreover, we validate the analytical and semianalytical results with obtained numerical results, and also compare them with previously published literature. A good agreement between the analytical and semianalytical results with the obtained numerical solution is observed as ±15%.