Sickle cell disease is a genetic disorder affecting the hemoglobin of red blood cells. When the blood oxygen concentration decreases, the mutated hemoglobin deforms the red blood cell, giving it a sickle shape. This stiffening of the red blood cells weakens their membranes and can lead to vaso-occlusive attacks. The project proposes to study the deformability of sickle red blood cells in microfluidics. Microfluidic circuits mimicking the mechanical perception of red blood cells by the spleen have been produced (Rigat-Brugarolas, 2014, and Picot, 2015) and optimized versions are under development (Gambhire, 2017). Splenomimetic chips combined with rapid camera analysis allow us to dynamically evaluate, in real time, the in vitro deformation capacities of red blood cells in the context of gene therapy for sickle cell patients.