An Integrated Lab on a CD Microfluidic Platform for High-Efficiency Blood Cell Separation and Passive Mixing

Abstract: Blood accounts for 7-8% of total body weight, with an average adult containing 4.5 to 6 quarts. It delivers oxygen and nutrients to cells, removes waste products, supports immunity, and regulates body temperature. Comprising over 4,000 components, including plasma, platelets, erythrocytes, and leukocytes, blood presents a challenge for isolating specific cell types due to its heterogeneity. In autologous therapies, target cells may be as rare as one per million background cells. This study presents the development of a compact disc (CD)-based microfluidic device for high-throughput, label-free separation of blood components. The system integrates three main modules on a single disk: cell sorting, fluid control, and cell lysis. The initial module utilizes Pinched Flow Fractionation (PFF) to separate red blood cells, white blood cells, and platelets based on size, achieving 99.99% efficiency. A capillary valve directs the sorted cells to the lysis module, where a chemical reagent is used to rupture cell membranes for downstream analysis. To enhance lysis efficiency, a micro mixer was incorporated using two zigzag geometries with internal barriers. The mixing performance of both designs was evaluated to determine optimal fluid interaction. This integrated, multifunctional CD platform offers a compact and effective solution for isolating and processing specific blood cells, with potential applications in diagnostics and personalized medicine.