| The work presented in this dissertation provides a novel technique of separation and isolation of colloidal entities from a complex fluid, based on an electrokinetic phenomenon called dielectrophoresis. A model has been developed using trajectory approach to determine the path of a given particle suspended in a medium inside a channel. The dielectrophoretic force field is modelled for interdigitated microelectrode array energized by phase-shifted ac signal. The analytic solution for electric field distribution has been validated by finite element analysis. Two different systems have been modelled to study both attractive and repulsive nature of the dielectrophoretic force, namely, a water-in-oil emulsion and a latex-in-water suspension. The model predicts an enhancement in the separation efficiency for the water-in-oil emulsion in presence of attractive dielectrophoretic force. Conversely, the model predicts a reduction in membrane fouling for the latex-in-water system in presence of repulsive dielectrophoretic forces. The initial experimental results show qualitative agreement with the model predictions. |
