Microvortex for focusing, guiding and sorting of particles

Abstract

We report a microvortex manipulator (MVM) that is a passive, scalable system with great potential for the manipulation and separation of particulate samples in microfluidic environments. The movement of particles is determined by a unique combination of helical flow, buoyant, and gravitational forces. Helical flows are induced by topographically patterned microchannel surfaces, which have previously been used for molecular mixing in microfluidic devices. Here we exploit the behavior of particles in the generated microvortices and present a generic strategy to focus, guide and sort particles. Particles can be focused and guided along arbitrary continuous patterns in a microchannel, which can be easily scaled up to focus multiple streams of particles in parallel. We theoretically illustrate the mechanism of our technique and experimentally demonstrate its applications in passive focusing of beads and cells into parallel streams and guiding of particles and cells. We also explore the application of the unique density-selectivity of microvortex focusing and successfully sort a mixture of two bead populations whose density difference is as small as 0.1 g/cm3.

Application of Flow Cytometry in the Studies of Microparticles

“…Another method for isolating MP which is gaining interest is referred to as microfluidic immunoaffinity method [Chen et al, 2010, Hsu et al, 2008. The propagators of this procedure point out that this method is much faster in comparison to differential centrifugation or sucrose gradient filtration and that it yields higher MP recovery rates [Chen et al, 2010].…”

“…shape, determinant surface profile, etc. The principle behind this method is to selectively bind MP populations to antibody-coated surfaces [Chen et al, 2010, Hsu et al, 2008, Cheng et al, 2007 . The method utilizes a flow channel of different dimensions, depending on the initial sample volume to be processed, which surface is chemically modified in order to later coat it with appropriate antibodies.…”

A transfer function approach for predicting rare cell capture microdevice performance

“…Differences in size compared to nontarget cells enable filtration (Hsu et al 2008;Sollier et al 2014), the passive focusing of cells using microvortexwall interactions (Hsu et al 2008;Sollier et al 2014), and streamline-separation approaches (Gleghorn et al 2010;Bhagat et al 2011) or high throughput. Changes in the cell membrane composition can lead to a differential electrokinetic response (Becker et al 1995;Shim et al 2013; Huang C et al 2014).…”

Microfluidic separation of viruses from blood cells based on intrinsic transport processes

“…Biomimedic devices with bifurcation structures 11,12 or expanding channels 13,14 exploit the plasma skimming effect to separate cells from plasma, but only a small fraction of plasma can be extracted since the cell free plasma layer is usually very thin. Other hydrodynamic devices such as deterministic arrays, 15 inertial focusing channels, 16,17 and microgroove structures 18,19 have been created to sort cells, but very few of them have been optimized a) Author to whom correspondence should be addressed. Electronic mail: xuc207@lehigh.edu.…”