V. Galon, C: Microfluidics

The mechanical properties of cells are often an indicator of disease. Red blood cells (RBCs) are easily deformable, thus its viability depends greatly on its extracellular medium. In this book, a microfluidic channel with the top wall decorated by a periodic array of rigid diagonal ridges that can sort RBCs with different stiffness is presented. It can give rise to a stiffness-dependent force, thus induce transverse separation. RBCs with extracellular media of 0.89% and 0.59% sodium chloride concentrations are separated. By bathing RBCs to various salt concentrations, its shape morphology and also its viscoelastic properties change. The total RBC count also correlated with the %salinity concentrations. These findings support observations relating salinity in blood with RBC count in physiological conditions. With a flow rate of 0.02mL/min and cell concentration of 3.2 x 1010cells/mL, the outlets of the microfluidic device were able to collect RBCs with a total retention of 78%. The analysis should help shed light to the role of physics in medicine. Microfluidics can be an approach to a powerful clinical tool for blood analysis and supplementary tool for disease detection method.