(266g) Motion of Capsules and Erythrocytes in Microfluidic Channels and Vascular Microvessels

The study of the interfacial dynamics of artificial or physiological capsules in confined geometries under Stokes flow conditions has seen an increased interest during the last few decades due to their numerous engineering and biomedical applications. Artificial capsules have wide applications in the pharmaceutical, food and cosmetic industries. In pharmaceutical processes, for example, capsules are commonly used for the transport of medical agents. In addition, the motion of red blood cells through vascular microvessels has long been recognized as a fundamental problem in physiology and biomechanics, since the main function of these cells, to exchange oxygen and carbon dioxide with the tissues, occurs in capillaries.

We emphasize that studies on the flow dynamics of small-size deformable particles still constitute a challenging problem in any type of research. To facilitate the computational study of these systems, we have developed spectral boundary element algorithms for the interfacial dynamics of three-dimensional droplets, capsules and erythrocytes in Stokes flow. Our methodologies preserve the main characteristic of the spectral methods, i.e. high accuracy and numerical stability as the number of discretization points increases, but without creating denser systems as spectral methods, used in volume discretization, do. Our method also exploits all the benefits of the boundary integral techniques, i.e. reduction of the problem dimensionality and great parallel scalability, while its element nature makes easy to incorporate complicated solid geometries.

In this talk we will present our results for the deformation and motion of capsules and erythrocytes in confined solid geometries including cylindrical, square and rectangular micro-channels. The effects of flow rate, capsule size and membrane type for several solid geometries will also be analysed.