The design of dielectrophoretic flow-through sorters using a figure of merit

Dielectrophoretic (DEP) forces produced by a pair of electrodes are used for such applications as particle sorting in microfluidic systems. In order to allow quantitative comparison of different DEP systems, we introduce a new figure of merit: dimensionless characteristic velocity corresponding to the maximum flow that can be used while still successfully deflecting the desired particles. This avoids the necessity of performing numerical simulations in order to compare designs and allows one to focus on general system design questions. The maximum deflection velocity is evaluated versus a characteristic length for four different sorter configurations, yielding curves that can be used as tools to design DEP sorters. Maximum flow predictions are compared with previously published theoretical and experimental results.