Vesicle shape transformations driven by confined active filaments

TL;DR

This study uses particle-based simulations to explore how active filaments inside elastic vesicles cause diverse shape transformations and dynamic behaviors, revealing new organizational states and design principles for active materials.

Contribution

It introduces a minimal model of active filaments within elastic vesicles, uncovering novel filament organizations and shape transformations driven by active stresses and deformability.

Findings

Discovery of new filament organizations like rings and caps

Dramatic, tunable vesicle shape transformations

Scaling models explaining emergent behaviors

Abstract

In active matter systems, deformable boundaries provide a mechanism to organize internal active stresses and perform work on the external environment. To study a minimal model of such a system, we perform particle-based simulations of an elastic vesicle containing a collection of polar active filaments. The interplay between the active stress organization due to interparticle interactions and that due to the deformability of the confinement leads to a variety of filament spatiotemporal organizations that have not been observed in bulk systems or under rigid confinement, including highly-aligned rings and caps. In turn, these filament assemblies drive dramatic and tunable transformations of the vesicle shape and its dynamics. We present simple scaling models that reveal the mechanisms underlying these emergent behaviors and yield design principles for engineering active materials with targeted shape dynamics.