Agent-based simulation studies of dry active nematics

We study an agent-based simulation model of active nematics, represented as flexible coarse-grained filaments, to explore the role of filament properties in governing collective behavior. We examine the relationship between filament flexibility and diffusion for a single isolated self-propelled filament, and the effects of particle flexibility on motility-induced phase separation in dense systems. Next, we study a system of dry extensile active filaments confined in a channel geometry with non-slip boundary conditions. We study interaction of topological defects with confining channel walls and the resulting defect density profiles across the channel width. Surprisingly, we observe that +½ defects concentrate and travel along channel walls, with defect density profiles that differ significantly from those observed in experimental and simulation studies of wet extensile systems [1]. We consider how the absence of hydrodynamic interactions may lead to these observed differences in defect dynamics and patterning. [1] Hardouin et al Comm Phys 2019 doi:10.1038/s42005-019-0221-x