Dielectrophoresis‐based microfluidic devices for field‐flow fractionation

Abstract

AbstractIn this communication, dynamic model for analysing micro‐objects’ path in dielectrophoresis (DEP)‐based microfluidic devices for executing field‐flow fractionation is formulated and subsequently employed for parametric study. Electrodes of finite length, that pass along the full width of the microchannel, are placed on the microchannel's upper and lower walls; each upper electrode and electrode gap aligns with a lower electrode gap and electrode, respectively. The model accounts for forces associated with inertia, sedimentation, DEP, drag and virtual mass. The model indicates that micro‐objects’ trajectory depends on actuation voltage, volumetric flow rate, micro‐object radius, electrode and gap dimensions, and microchannel height. The steady‐state levitation height is found to be independent of radius of micro‐object and volumetric flow rate while being dependent on electrode and gap dimensions, microchannel height and actuation voltage. The model predicts that there exists an optimal value of electrode and gap dimensions for which the steady‐state levitation height is maximum when all other parameters are kept constant. The efficacy of the device is demonstrated by separating a heterogeneous mixture of silica and polystyrene microparticles into homogeneous samples.