This talk will focus on cellular motility near surfaces. I will discuss surface motility in two very different cells, Myxococcus xanthus, a bacterial cell that performs gliding motility, and the sperm cell from the nematode Ascaris suum, which crawls. In both of these systems, I will discuss how the dynamical behavior of a crosslinked polymer network, or gel, can provide the thrust necessary to propel these cells along surfaces.
Numerical analysis of the complex, nonlinear equations that govern the gel dynamics are consistent with the forces and velocities measured for these cells.