Work

Particle Sweeping and Collection by Active and Living Filaments

Year: 2025

Type: article

Abstract: Biological and robotic systems often operate in confined environments where materials must be gathered without centralized control. Inspired by the effective collection strategies of aquatic worms ( and ), we investigate how active filaments autonomously aggregate dispersed non-Brownian passive particles. We study this process across four platforms: living worms, a robotic chain, Brownian dynamics simulations of active polymers, and a coarse-grained toy model. We show that aggregation emerges from repeated contact and body deformation—effectively, a sweeping or brooming motion—and demonstrate that clustering dynamics are governed by filament length and bending stiffness. Across systems, particle gathering follows a shared aggregation-fragmentation process, where the steady-state cluster size approximately follows a quadratic increase with the effective width of the path cleared by the filament W relative to the domain size D . This scaling provides a minimal geometric baseline for comparison across active filamentous systems. We find that filament flexibility modulates W , enabling more flexible filaments to sweep larger areas and collect more particles. These results establish a unifying framework for understanding how shape and flexibility influence transport and organization in active filament systems and filamentous robots.

Source: Physical Review X

DOI: 10.1103/yxp1-t43g