Insulator‐based dielectrophoretic separation of small particles in a sawtooth channel

Abstract

Insulator-based dielectrophoretic separation of small particles in a sawtooth channel is studied in the limit of dilute concentration. Pathlines for the movements of infinitesimal particles are constructed and the geometric changes of these pathlines are used to establish the criterion for blocking and trapping particles with different physical properties. The sharp corners of the sawtooth channel create much stronger dielectrophoretic force than channels with smooth corners for blocking particle movements. Particle blocking and trapping depend on particle properties and the geometry of the device. It is shown that once the channel geometric aspect ratios are specified, the blocking criterion depends on only a single dimensionless parameter C defined in terms of the particle mobility ratio (dielectrophoretic versus electrokinetic), the applied voltage and the spacing between the teeth. Selective blocking and trapping of particles can be realized by varying the geometry of the channel progressively. High-resolution separation can be achieved by tuning the differential in the parameter C to a desired level.

Direct current dielectrophoretic simulation of proteins using an array of circular insulating posts

“…In fact, it appears to be scale-invariant with respect to the geometry, so long as the nominal applied electric field remains constant between cases. This result is consistent with the reported experiments [6,39] showing the DEP capture of suspended proteins without requiring that they be aggregated into micron-size precipitates.…”

Tuning direct current streaming dielectrophoresis of proteins

“…Concomitantly, DEP has the potential to provide high molecular specificity. 1,2 Two major techniques are commonly used to produce electric field gradients for DEP manipulations. The first approach includes microstructured electrodes, 3 often embedded in microfluidic channels.…”

Dielectrophoretic monitoring of microorganisms in environmental applications

“…Many different approaches have been employed to apply DEP forces on particles, the most traditional manner is to use arrays of microelectrodes of a variety of geometries [34] and locations within a microchannel, from lateral electrodes [35] to threedimensional (3-D) cages [36,37] and 3-D electrodes [38]. Other novel approaches include: insulator-based DEP (iDEP) with 3-D columns or posts [39][40][41][42], oil menisci [43], glass spheres [44], microchannel with a geometry gradient [45,46], insulating hurdles [1,47], nanopipettes [19,48], spiral microchannels [49,50], and conical-pore membranes [51].…”