Simple elasticity problems inspired by biology
Serge Dmitrieff (Institut Jacques Monod)
Biological cells are physical elements under internal and external mechanical constraints. For instance, cell need to oppose exterior stress to maintain their shapes, and overcome large internal drag forces to transport cargo. I will discuss about the role of semi-flexible polymers called microtubules in these processes.
We will see that we can use simple physical notions from elasticity to address these problems : the maintenance the shape of blood cells can be understood as the buckling of a visco-elastic bundle in confinement, while some examples of intracellular transport to the cell center appears akin to Newton’s first theorem, albeit with elastic forces. Even minimal formulations of these problems are deceivingly simple, and yield interesting new physics, such as the metastability of disc-like cells, and unexpected scaling laws for centering forces.