Selective Concentration and Separation of Colloidal Particles By Positive Reservoir-Based Dielectrophoresis (rDEP)

Reservoir-based dielectrophoresis (rDEP) is a recently developed technique by our group that exploits the inherent electric field gradients at a reservoir-microchannel junction for particle and cell manipulations. It is based on the induced negative dielectrophoretic motion at the junction and has been demonstrated to trap and isolate particles based on size or surface charge and as well cells based on viability inside the reservoir. In this talk we present our recent experimental and numerical results for particle concentration and separation through positive rDEP. This separation is implemented by re-suspending a particle mixture into low-conductivity de-ionized water, which is compared with that in an electrolyte solution that induces negative rDEP.