Microfluidic chip for rapid and automatic extraction of plasma from whole human blood

A microfluidic chip comprising a straight microchannel and a fishbone filtration microchannel is proposed for the automatic separation of plasma from whole human blood. In the proposed device, the whole blood is introduced into the microfluidic chip by means of capillary forces and the plasma is then extracted from the whole blood via a size exclusion effect in the fishbone filtration channel. The microfluidic chip is fabricated from a single poly(dimethylsiloxane) mold and sealed with an etched glass substrate. The experimental results show that the microfluidic chip enables a whole blood sample with a volume of 10 μL to be separated within 75 s. Furthermore, it is shown that the average flow rate is equal to 0.02 μL/s and the residual cell concentration within the plasma collected at the outlet reservoir is <0.1 %. Overall, the device proposed in this study has a low cost, a straightforward operation, and a high filtration efficiency. As a result, it provides an ideal solution for the separation of plasma from whole human blood for point-of-care testing applications.