Effect of Cell Size for In-Flow Dielectrophoresis Cytometry-Based Dielectric Characterization

In this work, we use a microfluidic flow cytometer for the simultaneous imaging and dielectric characterization of individual biological cells within a flow. Knowledge of cell size in conjunction with dielectric properties enhance the ability to characterize individual cells. A high-speed camera is used to capture and track multiple cells in real-time as they traverse a microfluidic channel. This channel incorporates a coplanar electrode array, which produces a non-uniform electric field, thereby introducing dielectrophoretic forces, and translating to higher or lower velocity. Multiphysics electrostatic-fluid dynamics simulation is employed to establish the relationship between cell velocity, differential velocity and size and the Clausius-Mossotti factor (CMF), which is a function of the cell's dielectric properties. The system is evaluated using polystyrene microspheres (PSS) and demonstrated using Chinese hamster ovary (CHO) cells.