Capillary Flow Dynamics of Blood With Varied Hematocrit in Microfluidic Platforms

Blood is a complex fluid with non-newtonian behavior. Though the blood plasma is newtonian in nature, the Red Blood Cells (RBCs) in the blood contribute to the non-newtonian behavior. The study of the influence of the hematocrit (percentage of RBCs in the whole blood) in the capillary flow of the whole blood is highly desired to understand the non-newtonian flow of blood and change on the flow dynamics of whole blood with different concentrations of RBCs. In the capillary flow dynamics, the study of contact angle and its variations play a key role. So, in this manuscript the contact angle of the whole blood drop and the flow velocity of the whole blood with different hematocrit on the polydimethylsiloxane (PDMS) surface is studied with detailed scientific experiments. The contact angle was measured for whole blood drop with hematocrit of 35%, 40%, 45%, and 50% as 34°, 38°, 44°, and 48° respectively. Also, the flow velocity that is directly influenced by the contact angle in the capillary flow is measured with whole blood with hematocrit of 35%, 40%, 45%, and 50% as 9.23 mm/s, 8.45 mm/s, 7.32 mm/s, and 6.67 mm/s respectively. The experimental results helps to conclude that the increased hematocrit in the whole blood is increasing the contact angle and decreasing the flow velocity. Clinical Relevance - The study of the capillary flow dynamics of whole blood with different hematocrit helps the physicians to establish more accurate analysis of blood flow with different concentrations of RBCs.