Author(s): R. Sinaasappel, K. R. Prathyusha, H. Tuazon, E. Mirzahossein, P. Illien, S. Bhamla, and A. Deblais Active filaments collect nearby particles through sweeping motions driven by body bending. The size of the resulting clusters follows a simple geometric rule set by filament length and flexibility that unifies living, robotic, and simulated systems. [Phys. Rev. X 16, 011003] Published Mon Jan 05, 2026