Using velocimetry to extract DEP mobility from electrokinetic particles

In this report, Weiss et al. use a streak-based velocimetry technique to determine the electrokinetic properties of polystyrene particles. This can be a useful manner of characterizing suspended particles without manual tracking.

Abstract
Insulator-based dielectrophoresis (iDEP) is a powerful tool for separating and characterizing particles, yet it is limited by a lack of quantitative characterizations. Here, this limitation is addressed by employing a method capable of quantifying the DEP mobility of particles. Using streak-based velocimetry the particle properties are deduced from their motion in a microfluidic channel with a constant electric field gradient. From this approach, the DEP mobility of 1 μm polystyrene particles was found to be −2±0.4 10⁻⁸ cm⁴/(V² s). In the future, such quantitative treatment will allow for the elucidation of unique insights and rational design of devices.

Weiss N. G., Jones P. V., Mahanti P., Chen K. P., Taylor T. J. and Hayes M. A., Dielectrophoretic mobility determination in DC insulator-based dielectrophoresis. Electrophoresis. 2011, 32 (page numbers undetermined as of 8/23/11). [Link]