Fig. 1. Self-organized structures and dynamics of motor-filament mixtures driven by sliding of antiparallel filaments.

(A and B) Sketches of two consecutive motor steps when filaments are oriented (A) parallel and (B) antiparallel. The initially relaxed gray motor steps toward the filament polar end, it relaxes, and it makes a second step on the other filament and relaxes again. This results in net filament motion only for antiparallel motors. (C and D) Simulation snapshots for an initially disordered nematic system. The thin black box indicates the central simulation cell. (C) Short-time band formation and (D) long-time disordered structures. Filament colors indicate their orientation, illustrated by the color axis. (E) Number of antiparallel motors as a function of the persistence length ${\mathrm{\ell }}_{\mathrm{p}}$ and the bare motor velocity, measured by $p_{\mathrm{m}}^0$. (F) Peclet number as a function of the active force ${\tilde{F}}_{\text{act}}$ in Eq. 1. The table shows the parameter combinations used in (E) and (F). In all cases, ($\mathrm{\varphi },\tilde{L}$) = (0.66, 20).