(379f) Tailoring Active Matter Collective Behavior through Particle Anisotropy

Active matter studies have demonstrated that particle anisotropy can impact the collective behavior of a system. However, systems studied to date have served as one-off demonstrations of concept, rather than systematic treatments of anisotropy. Here, we computationally investigate the role of anisotropy in shape and active force director on the collective behavior of a two-dimensional active colloidal system. We find that shape and force anisotropy can combine to enable critical densities lower than those found in disks, and in some cases may actually elevate the critical density. Specifically, we find that tailoring particle anisotropy can enable more "effective" inter-particle collisions to tune the critical system density for phase separation. Additionally, we observe that the ability of clusters of anisotropic particles to stabilize rotational and translational motion results in nucleation of multiple clusters in the phase separation regime, which is not seen in systems of isotropic particles. In engineering applications for active colloidal systems, steric interactions such as those described here may offer a simple route for tailoring emergent behaviors in active materials.