Three-dimensional cellular focusing utilizing negative dielectrophoretic force generated by dual-planar electrodes

The main purpose of this paper was to numerically design an insulator-based dielectrophoretic microdevice with three-dimensional focusing of biological cells. The cells were introduced into the microchannel and pre-confined hydrodynamically by the funnel-shaped insulating structures close to the inlet. The dielectrophoretic force was employed to confine the cells with a negative dielectrophoretic response. The dual-planar electrodes connected to the opposite pole were designed at the top and bottom surfaces of the microchannel. Four insulating structures, which formed an X-pattern as shown in the microchannel, were employed to squeeze the electric field in a conducting solution, thereby generating high-electric-field regions. The results of numerical simulation indicated apparently that the increase of the electric field applied significantly enhanced the performance of focusing. According to the numerical results, decreasing the inlet velocity could increase the efficiency of focusing. The transient simulation of viable cell tracks also demonstrated that the three-dimensional focusing of particles was successfully achieved. The design proposed herein has no need of complicated flow controls for focusing of cells. The microdevice is easy to operate and integrate into further biomedical applications.