Separating microparticles by material and size using dielectrophoretic chromatography with frequency modulation.

Separation of (biological) particles ([Formula: see text]) according to size or other properties is an ongoing challenge in a variety of technical relevant fields. Dielectrophoresis is one method to separate particles according to a diversity of properties, and within the last decades a pool of dielectrophoretic separation techniques has been developed. However, many of them either suffer selectivity or throughput. We use simulation and experiments to investigate retention mechanisms in a novel DEP scheme, namely, frequency-modulated DEP. Results from experiments and simulation show a good agreement for the separation of binary PS particles mixtures with respect to size and more importantly, for the challenging task of separating equally sized microparticles according to surface functionalization alone. The separation with respect to size was performed using 2 [Formula: see text]m and 3 [Formula: see text]m sized particles, whereas separation with respect to surface functionalization was performed with 2 [Formula: see text]m particles. The results from this study can be used to solve challenging separation tasks, for example to separate particles with distributed properties.