High Velocity Dielectrophoretic Cell Separation Using Continuously Extended Sidewall Electrode Featuring Undercut Profile

Dielectrophoresis (DEP) as a label free technique has been widely accepted as one of the most effective tool for cell separation once integrated with microfluidic platform. Advanced DEP activated cell separators target for low-cost and fast cell separation with high separation efficiency. Recently microfluidic platforms incorporating microelectrodes made of conducting polymers leverage dielectrophoretic cell separation through replica molded volumetric electrodes that inherit the merit of 3D electrodes to generated highly effective DEP force field throughout the channel depth, and meanwhile allow cost-effective fabrication. Yet, such electrodes have limited way of configuration, being discretely embedded within fluidic sidewalls, which leads to compromised cell velocity for sufficient time of cell deflection under DEP force. This work for the first time presents long-range sidewall electrode made of conducting PDMS extending the full channel length and achieves continuous-flow dielectrophoretic separation of mammalian cells traveling at high velocity of 23.5 mm/s. We demonstrate the unique design and fabrication process of the long-range electrode featuring sidewall undercut and the DEP response of mammalian cells with distinctive dielectric property. We also carried out parametric study regarding the device capability of high velocity cell separation at varying voltage and cell loading density.