"In this dissertation, two dimensional and three dimensional, transient CFD simulations are conducted to investigate the active pumping and mixing in microfluidics driven by Electromagnetic/Lorentz force. Shallow disk/ring cylindrical microfluidic cell and shallow cuboid microfluidic cell with electrodes deposited on the bottom surface are modelled for mixing and pumping purposes respectively. By applying voltage across specific pair of electrodes, an ionic current is established in the weak conductive liquid present in the cell. The current interacts with an externally applied magnetic field generating a Lorentz force that causes fluid motion in the cell. Velocity vectors, electric potential distributions and ionic current lines are presented with high resolution in post-processing techniques. By switching on and off a pair of electrode, a "blinking vortex" is generated to induce the chaotic advection so as to enhance the mixing quality. Various particle trajectories based analyses using extensive post-processing of the simulation results show that the period T plays an important role in generating chaotic advection. Conducting polymer modified electrodes in microfluidics are also modeled and studied to build the bridge between the electrochemical properties of conducting polymer film and MHD flow manipulations in microfluidics. This dissertation establishes CFD simulation of MHD flow as a robust tool to study pumping and mixing in a microfluidic cell. The techniques developed in the present work are also applicable in MHD flow control in microfluidics"--Abstract, page iii.
Advisor: Isaac, Kakkattukuzhy M.
Missouri University of Science and Technology