A universal scaling law for active diffusion in complex media

Résumé fourni par la source

Understanding how active particles transport in structurally heterogeneous environments is a fundamental and challenging problem, with relevance to biological and synthetic microswimmers in tissues and porous media. Here, using granular experiments and computer simulations, we investigate the long-time diffusion of active tracers in quasi-two-dimensional heterogeneous media. We show that diffusion-structure relations established for passive systems fail to describe active transport across different activity levels. To resolve this, we formulate a modified diffusion-structure relation by incorporating the dimensionless persistence length Q = vdτr/dt, which captures the activity-induced extension of the effective interaction range. The proposed relation yields a consistent collapse within both experimental and simulation datasets across active and passive tracers, diverse environmental structures, and propulsion mechanisms. Our results thus provide a universal predictive framework for transport in non-equilibrium heterogeneous systems. Active particles often navigate complex, heterogeneous environments, which is crucial for understanding their transport in biological and synthetic systems. This study establishes a universal scaling law for active diffusion by introducing a modified diffusion-structure relation that incorporates a dimensionless persistence length, successfully unifying the behavior of active and passive tracers across various environments and propulsion mechanisms.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.