Dynamics of active filaments in porous media
Dr. Zahra Mokhtari (University of Goettingen)

With the aim of contributing to the understanding of the motion of biological agents in porous media, we consider a minimal model fo active elongated particles and show that the motion of such active filaments in a porous medium depends critically on flexibility, activity and degree of polymerization. For given Peclet number, we observe a transition from localisation to diffusion as the stiffness of the chains is increased. Whereas stiff chains move almost unhindered through the porous medium, flexible ones spiral and get stuck. Their motion can be accounted for by the model of a continuous time random walk with a renewal process corresponding to unspiraling. The waiting time distribution is shown to develop heavy tails for decreasing stiffness, resulting in subdiffusive and ultimately caged behaviour.