An efficient cell separation system using 3D-asymmetric microelectrodes

Abstract

An efficient 3D-asymmetric microelectrode system for high-throughput was designed and fabricated to enhance sorting sensitivities to the dielectric properties-size, morphology, conductivity, and permittivity-of living cells. The principle of the present system is based on the use of the relative strengths of negative dielectrophoretic and drag forces, as in a conventional 3D-microelectrode system. Whereas the typical 3D-microelectrode system has a constant electric field magnitude due to the constant width of the microelectrodes and a fixed gap between face-to-face microelectrodes, the present 3D-asymmetric microelectrode system has electric fields of continuously varying magnitudes along the transverse direction of a channel owing to the changing widths of the electrodes in the half-circular shaped cross section of the microchannel. Thus, varying dielectric forces are generated, leading to increased sorting sensitivity through differentially induced forces to definitely distinct cell types. Numerical analysis verified the improved sensitivity of the present system for sorting living cells. The feasibility of using the newly fabricated system under experimental conditions was tested by demonstrating that a mixed population of mouse P19 embryonic carcinoma (EC) and red blood cells (RBCs) was effectively sorted to different wells depending on their respective relative physical properties.

The potential of a dielectrophoresis activated cell sorter (DACS) as a next generation cell sorter

“…DEP trapping techniques are mainly used to isolate particles within a still fluid utilizing p-DEP force [22][23][24][25]. The TwDEP force, DEP-FFF and DEP barrier techniques are realized via angled or vertical electrode pairs, and they are generally implemented with n-DEP force within the micro channel with fluidic flow [26][27][28][29][30][31][32]. The latter techniques have a striking advantage in terms of throughput since the continuous loading of target cells along the fluidic flow allows for continuous cell separation.…”

Controllable alignment of elongated microorganisms in 3D microspace using electrofluidic devices manufactured by hybrid femtosecond laser microfabrication

“…Compared with conventional electrode fabrication methods, this technique provides a simpler scheme to reliably install electrodes with flexible configurations at any position in 3D microfluidic structures. In addition to the development of the 3D continuous control of the electro-orientation of cells and particles, we expect that this technique can be extended to the fabrication of different types of electrofluidic devices for 3D dielectrophoretic manipulation of biological samples [51][52][53] , 3D electrorotation in microscale spaces 54,55 , and electrical impedance sensors 56,57 . The incorporation of photonic components, such as optical waveguides, fibers, and microlenses 38 , into the fabricated electrofluidic devices using the same fs laser would significantly enhance the performance of biochips, paving the way to 3D 'all-in-one' lab-on-a-chip devices.…”

Continuous separation of colloidal particles using dielectrophoresis

“…In a similar work, the angle of electrodes with respect to the direction of fluid flow has been varied to facilitate DEP separation of particles of varying size, starting from 250 to 12 um [68]. Other related work using concepts similar to this include trapezoidal electrode arrays for continuous separation of microparticles [69], zig-zag paired electrode arrays in silicon and glass [70], high speed switched attenuators [71], a 3D fan-shaped electrode system [72], and a piece-wise curved array [73]. An elegant application of this type of design using imposed conductivity gradients has also been demonstrated [74].…”