Effect of Fin-Shaped Electrodes on Flow Mixing and Pressure Drop in an Electroosmotic Micromixer

Production of a homogeneous solution is of great interest for Lab-on-a-Chip (LOC) applications. Since the fluid flow in microchannels is laminar, the LOC devices have low mixing efficiency in passive mixers. The present study proposes a novel electroosmotic micromixer in which the electrodes have a fin-shaped structure in the mixing chamber. In other words, the combined effect of obstacle and electro-osmosis is evaluated. The effect of various parameters such as electrode angle, electrode height, inlet velocity, alternating current, and frequency on mixing index and pressure drop is investigated. Vortices are formed around the electrodes due to the applied electric field and their fin-shaped structure. It is revealed that the mixing index is an increasing function of applied voltage. The results demonstrate that there is an optimal value for the parameters, including frequency, electrode height, inlet velocity, and electrode angle. An increase in the mixing efficiency is accompanied by an enhancement in the pressure drop. It is revealed that the maximum efficiency is achieved when the electrode height is ۵ μm and the electrode angle is ۶۰°. The coefficient of performance of the proposed micromixer is more than that of the reference mixer when the electrode height is ۲.۵ μm and the electrode angle is ۹۰°.

کلیدواژه ها:

Lab-on-a-chip ، Electroosmotic micromixer ، Mixing efficiency ، Pressure drop ، LOP