DC dielectrophoretic focusing of particles in a serpentine microchannel

Abstract

Focusing particles into a tight stream is usually a necessary step prior to separating and sorting them. We present herein a proof-of-concept experiment of a novel particle focusing technique in DC electrokinetic flow through a planar serpentine microchannel. This focusing stems from the cross-stream dielectrophoretic motion induced within the channel turns. The observed particle focusing behavior is consistent with the predicted particle trajectories from a numerical modeling.

dc electrokinetic transport of cylindrical cells in straight microchannels

“…[2][3][4][5][6] The success of these electrically controlled microfluidic devices for particle transport relies on a comprehensive understanding of fluid and particle behavior in these devices. However, most existing theoretical [7][8][9][10][11] and experimental [12][13][14][15][16][17][18][19] studies on the electrokinetic transport in microfluidic devices have been performed exclusively on spherical particles. In fact, a large amount of particles used in microfluidic applications, such as biological entities 1 and synthetic nanowires, 20,21 is nonspherical.…”

“…11,15 Dielectrophoresis refers to a nonlinear electrokinetic phenomenon 30 in which a force is exerted on a dielectric particle when it is subjected to a spatially nonuniform electric field. This kind of electrokinetic phenomenon has been widely used to manipulate spherical particles in microfluidics such as particle trapping, [31][32][33][34][35] separation, 16,[35][36][37][38][39][40][41] focusing, 14,18,35 and cell discrimination. 42,43 Previous numerical and experimental studies demonstrate that the DEP effect should be taken into account to study the electrokinetic transport of spherical particles where nonuniform electric fields are present.…”

Size-Based Separation of Particles and Cells Utilizing Viscoelastic Effects in Straight Microchannels

“…[4][5][6] Microfluidic systems have been proven to be promising tools for particle/cell manipulation with higher sensitivity and accuracy than their macroscale counterparts. The last decade has seen extensive development of microfluidic approaches for particle/cell manipulation that resort to immunocapture, 7 externally applied physical fields, [8][9][10][11][12][13][14][15][16][17][18] microfiltration, 19,20 gravitational sedimentation, 21 or deterministic lateral migration. 22,23 More recently, cross-streamline migration induced by the hydrodynamic effects of carrier media, such as inertia 24,25 and viscoelasticity, 26,27 has shown its promise for effective particle/cell manipulation without need of labeling and external force fields.…”

A new approach to design an efficient micropost array for enhanced direct-current insulator-based dielectrophoretic trapping

“…Consequently, the net particle velocity along the electric field line is zero in the zone of trapping. Thus, the trapping DEP flow condition becomes as other authors reported [25][26][27][28]:…”