Negative Dielectrophoretic Particle Positioning in A Fluidic Flow

Abstract

In this work, we report the control of a microparticle position within fluid flow based on its size by using a repulsive force generated with negative dielectrophoresis (n-DEP). The n-DEP based fluidic channel, which was consisted of navigator and separator electrodes, was used to manipulate the particle flow in the center of channel and to control the particle position in the fluidic flow. The mixture of 10 µm-and 20 µm-diameter particles was introduced into the channel with 30 µm height at 700 µm/s. On applying an AC voltage (23 V peak-peak and 7 MHz) to the navigator electrodes on the upper and lower substrates in a n-DEP frequency region, the suspended microparticles were guided to the center of the fluidic channel and then channelled through the passage gate positioned at the center of the channel. The AC electric field was also applied to separator electrodes, resulting in a formation of flow paths with low electric fields. The separator was consisted of the five band electrodes with the different gap spaces with the adjacent band, which allow to forming the flow paths with different electric fields. The microparticles separately flow in line along the paths formed between the band electrodes, the 10 µm-diameter particles mainly flow through the narrow path and 20 µm-diameter particles through the wide path arranged at the outside from the center. These results indicated that positions of two types of microparticles in the fluidic channel were easily separated and controlled using the n-DEP. The present procedure therefore yields a procedure for the DEP based simple and miniaturized separators.

Microfluidic Separation of Blood Cells Based on the Negative Dielectrophoresis Operated by Three Dimensional Microband Electrodes

“…The cross-over frequency, where the net dielectrophoretic force becomes zero, could be found between 100–400 kHz. The DEP behavior of THP-1 cells has been investigated in previous our report [ 34 ]. Similar properties were observed for THP-1 cells with the lower shift of the cross-over frequencies.…”

“…The slanted electrodes with different length and angle were developed to separate the subpopulation multiples [ 31 , 32 ]. We also fabricated the electrode array with different gaps in the channel and applied it to control the flow position of each cell with different sizes [ 33 , 34 ].…”

Development of three-dimensional integrated microchannel-electrode system to understand the particles' movement with electrokinetics

“…16 In microfluidic systems, a pressure-driven flow by electroosmotic force is often applied to deliver the sample or cells into the target region. 17 Exploiting the resultant effect of the combination of the above electrokinetic forces was used as field-flow fractionation (FFF) 18 by Kuczenski et al, 19 Gielen et al, 20 Wang et al, 21 and Yasukawa et al 22 to manipulate the particles in two dimensional scope, while the electrokinetic forces generated from a simple two dimensional planner electrodes. The overall mechanism of these forces in 2D is straightforward.…”