Locomotion of Active Polymerlike Worms in Porous Media

There have been many recent advancements in understanding active matter as a framework to study microbial motility. However, most of these studies focus on the motility of rigid and point-like shapes in free environments. In nature, microorganisms tend to be elongated and flexible and live in complex and crowded environments.

We investigate the locomotion of thin, living T. Tubifex worms that behave as active polymers in model quasi-2D porous media made of an array of 3D printed pillars. These active worms spread in crowded environments with dynamics that depend on the concentration of obstacles and whether the lattice exhibit a random or an ordered phase. Our findings show that the motion of active polymers can be optimized by tuning these parameters and rationalizing using well-known reptation concepts borrowed from classical polymer dynamics. Additionally, we found that the spread of the active worm can be strongly enhanced by decreasing the worm’s activity, allowing us to passively sort the worms by activity.