Guided Dielectrophoresis: A Robust Method for Continuous Particle and Cell Separation

In this paper, we report on an on-chip separation device that is based on guided dielectrophoresis (DEP). The simple design comprises a pair of electrodes and a microfluidic channel for sample delivery. Continuous separation into two distinct populations (corresponding to positive and negative DEP, respectively) in the microchannel was achieved without the need of accurate hydrodynamic focusing or multiple excitation frequencies. In this device, the sample position after separation is only determined by the geometry of the channel and the electrodes, which results in a separation process that is robust against fluctuations in separation voltage and flow caused by vibrations in the setup. The separation principle has been simulated and proven by measurements comprising polystyrene beads and two human cell lines: Jurkat (T-cell leukemia) and HeLa (cervical cancer). Automatic image processing was used to detect the particle positions at the separation channel outlet.