Continuous inertial microparticle and blood cell separation in straight channels with local microstructures

Abstract

Fluid inertia which has conventionally been neglected in microfluidics has been gaining much attention for particle and cell manipulation because inertia-based methods inherently provide simple, passive, precise and high-throughput characteristics. Particularly, the inertial approach has been applied to blood separation for various biomedical research studies mainly using spiral microchannels. For higher throughput, parallelization is essential; however, it is difficult to realize using spiral channels because of their large two dimensional layouts. In this work, we present a novel inertial platform for continuous sheathless particle and blood cell separation in straight microchannels containing microstructures. Microstructures within straight channels exert secondary flows to manipulate particle positions similar to Dean flow in curved channels but with higher controllability. Through a balance between inertial lift force and microstructure-induced secondary flow, we deterministically position microspheres and cells based on their sizes to be separated downstream. Using our inertial platform, we successfully sorted microparticles and fractionized blood cells with high separation efficiencies, high purities and high throughputs. The inertial separation platform developed here can be operated to process diluted blood with a throughput of 10.8 mL min(-1)via radially arrayed single channels with one inlet and two rings of outlets.

Inertial Microfluidic Cell Stretcher (iMCS): Fully Automated, High‐Throughput, and Near Real‐Time Cell Mechanotyping

“…In brief, as shown in Figure 1b, cells flow in a low aspect ratio straight channel interspersed with a series of elevational obstacles arranged orthogonally. Along with inertial lift forces, each obstacle induces a pair of helical secondary flows [19] that direct cells into a single equilibrium position (Movie S1). This inertial cell focusing process is an extremely important step because cells positioned in a single imaging plane are critical for high quality imaging.…”

Microfluidic co-flow of Newtonian and viscoelastic fluids for high-resolution separation of microparticles

“…Coupled with the secondary flows induced in structured [14][15][16][17] or curved 18-21 microchannels, inertial microfluidics has been intensively used for enrichment, separation, and stretching measurement of cells and microparticles. In comparison with inertial microfluidics generally using Newtonian fluids as the carrier medium, viscoelastic microfluidics relies on the elasticity by adding synthetic or biological polymers into the carrier medium.…”

Deterministic Migration‐Based Separation of White Blood Cells

“…Alternatively, WBCs can be sorted from RBCs based on their intrinsic physical differences in magnetic susceptibility, dielectric properties, size, and rheological properties . Microfluidic devices have proven effective for such application, by providing precise cell control over fluidic and separation forces as well as a simple separation setup .…”

“…The devices can be classified into two major categories: dilute‐blood separators which require blood dilution prior to separation, and whole‐blood separators which enable the separation of WBCs from undiluted whole blood. In dilute‐blood approaches, WBCs can be isolated from RBCs upon the application of a magnetic field, an electric field or inertial effects . The limitation of the approaches is that numerous blood cells (≈4 to 6 million cells per μL) in whole blood and their interactions can complicate the separation processes typically designed for single cells, resulting in significant blood dilution and low separation throughput.…”

“…Peripheral WBCs consist of several subpopulations such as lymphocytes, monocytes, and polymorphonuclear cells. [ 1 ] In many human diseases, susceptibility, [ 6 ] dielectric properties, [ 7 ] size, [8][9][10][11][12][13][14] and rheological properties. [15][16][17] Microfl uidic devices have proven effective for such application, by providing precise cell control over fl uidic and separation forces as well as a simple separation setup.…”