Blood plasma separation in elevated dimension T-shaped microchannel

Abstract

In recent years, microfluidic chips have proven ideal tools for biochemical analysis, which, however, demands a unique and compatible plasma separation scheme. Various research groups have established continuous flow separation methods in microfluidic devices; however, they have worked with relatively small dimension microchannels (similar to the blood cell diameter). The present work demonstrates separation of plasma by utilizing the hydrodynamic separation techniques in microchannels with size of the order of mm. The separation process exploits the phenomenon, which is very similar to that of plasma skimming explained under Zweifach-Fung bifurcation law. The present experiments demonstrates for, the first time, that applicability of the Zweifach-Fung bifurcation law can be extended to dimensions much higher than the suspended particle size. The T-microchannel device (comprising perpendicularly connected blood and plasma channels) were micro-fabricated using conventional PDMS micro-molding techniques. Three variables (feed hematocrit, main channel width, and flow rate distributions) were identified as the important parameters which define the device's efficiency for the blood plasma separation. A plasma separation efficiency of 99.7 % was achieved at a high flow ratio. Novel concepts of 2-stage or multiple plasma channel designs are also proposed to yield high separation efficiency with undiluted blood. The possible underlying principle causing plasma separation (viz. aggregation and shear thinning) are investigated in detail as part of this work. The results are significant because they show nearly 100 % separations in microchannels which are much easier to fabricate than previously designed devices.

In microfluidico: Recreating in vivo hemodynamics using miniaturized devices

“…Under these conditions, a cell-free layer is formed near the wall that is enriched in platelets and depleted of red blood cells. In fact, extreme geometries allow skimming of the cell free layer to separate plasma or platelet rich plasma [9], especially with partially-diluted blood.…”

Low-cost, disposable microfluidics device for blood plasma extraction using continuously alternating paramagnetic and diamagnetic capture modes

“…Many different types of microfluidics devices and approaches have been proposed in order to efficiently separate blood cells and blood plasma in blood. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] One of representative separation methods is to use filtration method. Crowley and Pizziconi 9 demonstrated a microfluidics device which separated blood plasma from whole blood sample using cross filtration method.…”

“…Other hydrodynamic forces such as Zweifach-Fung bifurcating effect have been used to extract blood plasma. 8,[13][14][15] Shamsi et al 15 designed and fabricated a microfluidics device with a main channel and a series of daughter channels for blood plasma separation using bifurcating effect and plasma skimming.…”

Microdevice for plasma separation from whole human blood using bio-physical and geometrical effects

“…Another issue with employing diluted blood samples in a plasma separation microdevice may be with respect to the quality of plasma extracted383940. Understandably, there is uncertainty associated with analyte detection from these diluted blood plasma samples.…”