Quantifying dielectrophoretic collections of sub-micron particles on microelectrodes

This paper presents a technique for measuring and quantifying the dielectrophoretic collection of sub-micron particles on planar microelectrode arrays. Fluorescence microscopy and video recording is used to measure the number of particles collecting on an electrode as a function of time for various experimental parameters, such as applied electrode voltage and frequency. Video images are processed using analytical methods that take advantage of the geometrical properties of the electrode array to extract quantitative information which is used to characterize the dielectric properties of particles. The time-dependent collection profiles can be characterized by three parameters: the initial dielectrophoretic collection rate, the initial to pseudo-steady-state transition and the rise time. This method can be used as a general technique to characterize the dielectrophoretic properties of populations of sub-micron-scale particles.