Separation of mixtures of particles in a multipart microdevice employing insulator‐based dielectrophoresis

Abstract

Dielectrophoresis is the electrokinetic movement of particles due to polarization effects in the presence of non-uniform electric fields. In insulator-based dielectrophoresis (iDEP) regions of low and high electric field intensity, i.e. non-uniformity of electric field, are produced when the cross-sectional area of a microchannel is decreased by the presence of electrical insulating structures between two electrodes. This technique is increasingly being studied for the manipulation of a wide variety of particles, and novel designs are continuously developed. Despite significant advances in the area, complex mixture separation and sample fractionation continue to be the most important challenges. In this work, a microchannel design is presented for carrying out direct current (DC)-iDEP for the separation of a mixture of particles. The device comprises a main channel, two side channels and two sections of cylindrical posts with different diameters, which will generate different non-uniformities in the electric field on the main channel, designed for the discrimination and separation of particles of two different sizes. By applying an electric potential of 1000 V, a mixture of 1 and 4 μm polystyrene microspheres were dielectrophoretically separated and concentrated at the same time and then redirected to different outlets. The results obtained here demonstrate that, by carefully designing the device geometry and selecting operating conditions, effective sorting of particle mixtures can be achieved in this type of multi-section DC-iDEP devices.

Dielectrophoretic differentiation of mouse ovarian surface epithelial cells, macrophages, and fibroblasts using contactless dielectrophoresis

“…In iDEP, insulating structures are straddled between two electrodes to cause regions of high and low electric field intensity, resulting in non-uniformity of the electric field. 29 Such systems were proposed by Cummings and Singh 29 and have been applied successfully for manipulation of DNA, 30 separation of live and dead cells, 32,33 and separation of different species of cells. 34 Contactless dielectrophoresis (cDEP) is a new technique for manipulating cells which eliminates direct contact between the sample and electrodes.…”

Modelling of electrokinetic phenomena for capture of PEGylated ribonuclease A in a microdevice with insulating structures

“…Moreover, previous works exhibit a trend in the values assigned to the correction factor, i.e., the smaller the particle, the higher the correction factor. [33][34][35] For example, for polystyrene beads with diameters of 1 and 4 lm, correction factors of 600 and 100 were required, respectively, to predict DEP trapping. 33 The slope of a correction factor versus particle diameter plot for that work would have a value of À166.667 Â 10 6 (1/m).…”

“…[33][34][35] For example, for polystyrene beads with diameters of 1 and 4 lm, correction factors of 600 and 100 were required, respectively, to predict DEP trapping. 33 The slope of a correction factor versus particle diameter plot for that work would have a value of À166.667 Â 10 6 (1/m). Assuming the ideal case in which the correction factor is a linear function of particle diameter, the correction factor required to predict protein particle trapping would have a value in the 750-800 range.…”

Particle Manipulation in Insulator Based Dielectrophoretic Devices1

“…Experimental work was carried out in microdevices made from PDMS using conventional soft lithography techniques [24]. Channels and insulating structures were defined in SU-8 3050 (MicroChem, Newton, MA) on a Si wafer (Silicon Inc, Boise, ID).…”