Microfluidic Fluorescence-Activated Cell Sorting via Gradient Dielectrophoresis

Conventional fluorescence-activated cell sorting (FACS) systems are usually expensive and require large sample volumes. In this study, we present a compact microfluidic system based on gradient dielectrophoresis (gDEP-μFACS). The device integrates inertial self-ordering, laser-induced fluorescence detection, and programmable cell deflection on a single chip. It uses asymmetric curved microchannels to achieve uniform single-cell distribution and curved gradient electrodes to generate precise electric fields for cell sorting. Intermittent sinusoidal signals help prevent cells from sticking to the electrodes. The system can efficiently screen fluorescent microspheres and isolate human cancer cells expressing green fluorescent protein (GFP) with high viability. Its portable design enables gentle, accurate sorting of small samples, making it suitable for on-chip cytometry and point-of-care testing.