Effects of geometry and electric field on non-Newtonian fluid mixing in induced charge electrokinetic micromixers

This study presents a numerical simulation of the mixing behavior of non-Newtonian fluids in a T-shaped micromixer, focusing on the influence of geometric and electrical parameters through induced charge electrokinetics. The simulation explores how a conductive link within the micromixer generates micro-vortices under an applied electric field, thereby enhancing mixing. Key parameters such as link length, position, shape, and orientation angle are systematically examined, with fluid rheology described using the power law model. Results show that pseudoplastic fluids (n < 1) achieve superior mixing compared to dilatant fluids (n > 1) due to larger recirculation zones. The applied electric field significantly impacts mixing performance, with the dimensionless vortex length increasing by 1.8 times and maximum induced velocity rising by 200 % as the electric field increases from 20 to 100 V/cm. Longer conductive links and angled orientations further enhance mixing. For a pseudoplastic fluid (n = 0.8), adjusting the orientation of multiple conductive links at 5 degrees improves mixing efficiency from 76 % to 97 % by promoting micro-vortex formation across fluid interference layers. These findings provide valuable insights into optimizing flow dynamics, contributing to the design of more efficient lab-on-chip devices for research and diagnostic applications.