The dynamics of deformable objects, in particular biological cells, in microfludic channels isan interesting research topic, from both theoretical and practical point of view. In this project, I used COMSOL Multiphysics to simulate the trajectories of deformable cells bumping into a hard pillar inside a microfludic channel. Elevated applied pressures were tested and both nonnucleated and nucleated cells were considered.
*Nonnucleated cells (color of fluid: velocity, color of cell: von Mises stress)*
*Nucleated cells (color of fluid: velocity, color of cell: von Mises stress)*
In both cases, the cytoplasm is set to be hyperelastic with the bulk modulus of 1 MPa. The nucleus if present is also defined as a hyperelastic material with the bulk modulus of 5 MPa. Clearly, the presence of a nucleus makes the cell less deformed. At all pressure values and for both cell types, the cells were shown to be compressed against the pillar, gradually acclerate, and finally relax into original shape after passing the pillar. An interesting bouncing behavior can be observed at high pressure.