On-chip high-speed sorting of micron-sized particles for high-throughput analysis

Abstract

A new design of particle sorting chip is presented. The device employs a dielectrophoretic gate that deflects particles into one of two microfluidic channels at high speed. The device operates by focussing particles into the central streamline of the main flow channel using dielectrophoretic focussing. At the sorting junction (T-or Y-junction) two sets of electrodes produce a small dielectrophoretic force that pushes the particle into one or other of the outlet channels, where they are carried under the pressure-driven fluid flow to the outlet. For a 40 mm wide and high channel, it is shown that 6 mm diameter particles can be deflected at a rate of 300/s. The principle of a fully automated sorting device is demonstrated by separating fluorescent from non-fluorescent latex beads.

Review Article: Recent advancements in optofluidic flow cytometer

“…[66][67][68][69] In order to recover the rich information ͑e.g., stochastic behavior of individual cells͒ from cell-based assays, it is essential to extract single cells from a population/subpopulation of cells. As a result of significant advances in microfabrication technologies, numerous microfluidic cell sorters exploiting various sorting actuation mechanisms ͑e.g., electro-osmotic, [70][71][72] optophoretic, 73 hydrodynamic, 24,74,75 piezoelectric, 56,61,76 etc.͒ have emerged ͑see Table I͒. Table II lists some of the benefits and detractions of these various sorting mechanisms that have been explored for use in FACS systems.…”

“…In addition to cell trapping, Holmes et al 72 achieved particle deflection by embedding a two-electrode system oriented parallel to the flow, causing DEP forces perpendicular to the fluid flow ͑Fig. 12͒.…”

Microfluidic sorting of microtissues

“…Microfluidic platforms have been utilized for several years to improve efficiency, accessibility, and flexibility of systems designed to purify small particles [15][16][17][18][19] and have been utilized more recently to purify large particles based on particle size. 20,21 In particular, a microfluidic 1 mm glass capillary sorting mechanism was developed using diode laser bars to optically trap or deflect particles up to 200 lm in diameter.…”

Digital signal processing methods for impedance microfluidic cytometry

“…Data acquisition and analysis is performed using a PC. Full details of this system have been reported previously (Gawad et al 2001(Gawad et al , 2004Cheung et al 2005;Holmes et al 2005;Morgan et al 2006Morgan et al , 2007.…”

“…Ayliffe et al (1999) developed a micro-impedance measurement device with integrated electrodes to measure the impedance of femtoliter quantities of ionic solutions and single biological cells. Following on this work, impedance micro-cytometers capable of measuring hundreds of individual cells were developed (Gawad et al 2001(Gawad et al , 2004Cheung et al 2005;Holmes et al 2005;Morgan et al 2006Morgan et al , 2007Sun et al 2007a). An example of a cytometer is shown in Fig.…”