A novel, compact and efficient microchannel arrangement with multiple hydrodynamic effects for blood plasma separation

Separating plasma from blood using a microfluidic platform is favored and beneficial in point-of-care diagnostics. This paper presents a microdevice enabling blood plasma separation. In the present work, the microfluidic channel was innovatively designed in such a way that a combination of effects such as Fahraeus effect, bifurcation law, cell-free region, centrifugal action, and constriction-expansion is utilized together for skimming plasma from human blood. Microdevices were designed and fabricated using PDMS (poly-di-methyl siloxane), which is a bio-compatible material. The results obtained are extremely encouraging in terms of separation efficiency. Separation efficiency of almost 100 % has been achieved at moderate hematocrit contents of around 20 %. The separation efficiency for undiluted blood (hematocrit of 45 %) is around 80 %. This microdevice is free from clogging issues that are usually encountered in blood plasma separation devices.