Optimization of Blood Microfluidic Co-Flow Devices for Dual Measurement

Microfluidics is a prominent field used to analyze small amounts of biological fluids. Co-Flow microfluidic devices can be used to study red blood cell aggregation in blood samples under a controlled shear rate. The purpose of this paper is to optimize the parameters of a co-flow device in order to produce a linear velocity profile in blood samples which would provide a constant shear rate. This is desired as the eventual goal is to use an ultrasonic measurement sensor with the co-flow microfluidic device to analyze red blood cell aggregates. Computational fluid dynamic simulations were performed to model a microfluidic device. The simulation results were verified by µPIV of the experimental microfluidic device. Modifications were made to the geometry and flow rate ratio of the microfluidic device to produce a more linear velocity profile. By using a flow rate ratio of 50:1 of shearing fluid to sheared fluid, we were able to achieve a velocity profile in the blood layer that is approximately linear.