Guillaume Duclos Abstract

Active matter describes out-of-equilibrium materials composed of motile building blocks that convert free energy into mechanical work. The continuous input of energy at the particle scale often leads to collective behaviors not found in passive materials. While motile cells use both molecular motors and non-equilibrium turnover to generate forces, the latter remains a largely unexplored mechanism to power reconstituted active systems. In this talk, I will describe our recent efforts to build simple active systems composed of treadmilling actin filaments. Micron-scale beads covered with an actin nucleating protein self-propel when immersed in a solution of actin monomers and actin-binding proteins, mimicking the motility of small parasites such as listeria. Preliminary data demonstrate rich emergent dynamical phases at multiple length scales. The coupling between reaction/diffusion-mediated pattern formation and actin polymerization mimics fundamental features of morphogenesis not observed in motor-based active matter. In this talk, I will present how to leverage this underexplored stress-generating mechanism to identify generic emergent behaviors in active matter.