Two-Fluid Method-Based Three-Dimensional Simulation of Blood Plasma Separation in a Complex and Elevated-Dimension Microchannel

Separating blood plasma is a critical and common task in daily laboratory analyses for diagnosing blood-related disorders and diseases. Optimizing the efficiency of blood plasma separation microdevices through numerical approaches can substantially reduce the time and expense of disease diagnosis. This work presents a numerical investigation of blood flow within a complex, elevated-dimension microchannel using a continuum-based two-fluid method. The simulations focus on two innovative passive blood-based microchannels designed for blood plasma separation applications that utilize blood’s various geometrical and hydrodynamic phenomena. The study qualitatively illustrates significant phenomena such as the Zweifach–Fung effect (bifurcation law), Fahraeus effect, Fahraeus–Lindquist effect, plasma skimming, and migration of red blood cells within the passive hydrodynamic blood plasma separation microdevice. These phenomena are crucial for achieving effective blood plasma separation within the microdevice. The qualitative analysis conducted in this study aligns with experimental observations, providing confidence in the model’s accuracy. Additionally, the study offers a quantitative analysis of local hematocrit profiles and cell-free layers at different locations within the microdevice, providing blood flow insights. The proposed continuum-based two-fluid method is a valuable tool during the initial design phase of passive blood-based microdevices, offering significant cost and time savings.