Limitations on the scale of an electrode array for trapping particles in microfluidics by positive dielectrophoresis

Experiments were performed on dilute suspensions of polarized particles in microfluidics with electrodes of different sizes arranged parallel and perpendicular to the flow. We identified the conditions under which the interparticle electric interactions do not affect the particle trapping in the high-field strength regions. In particular, there exists a lower bound on the scale of the microelectrodes, below which the expected improvement in positioning the particles in the preselected locations cannot be attained.