(443b) Fundamentals of Dielectrophoretic Particle Trapping in Arrays of Insulating Structures

This work is focused on insulator based DEP (iDEP), a dielectrophoretic mode that uses insulating structures between two external electrodes to create electric field gradients and generate dielectrophoretic forces on particles. This study includes experimental and mathematical modeling work. COMSOL Multiphysics was used to determine the distribution of the electric field and electric field gradient within an array of insulating posts. The distribution of these parameters was studied at each constriction between the insulating posts, in order to predict the net particle velocity over different electrokinetic and dielectrophoretic regimes. Experimentation was carried out with devices made from polydimethylsiloxane (PDMS) employing standard soft lithography techniques. All experiments were performed by applying DC electric potentials across the iDEP microchannels and observing particle response. The results clearly depict how particle trapping in iDEP devices occurs in the regions where the different forces acting on the particles are balanced. The findings from this study provide a deeper understanding of particle trapping in iDEP devices.