Vesicle shape transformations driven by confined active filaments

Matthew S E Peterson,Aparna Baskaran,Michael F Hagan

doi:10.1038/s41467-021-27310-8

Matthew S E Peterson, Aparna Baskaran + Show 1 more

Open Access

https://doi.org/10.1038/s41467-021-27310-8

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Journal: Nature Communications	Publication Date: Dec 1, 2021
Citations: 27	License type: open-access

Affiliation: Brandeis University

Abstract

In active matter systems, deformable boundaries provide a mechanism to organize internal active stresses. 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.

Highlights

IntroductionDeformable boundaries provide a mechanism to organize internal active stresses
In active matter systems, deformable boundaries provide a mechanism to organize internal active stresses
From a technological perspective, harnessing active stresses to drive particular emergent behaviors could enable a new class of materials with life-like properties that would be impossible in traditional equilibrium materials

Summary

Introduction

Deformable boundaries provide a mechanism to organize internal active stresses. The field of active matter has identified two key mechanisms that provide control over active stress organization: (1) anisotropic interactions between active components that realign forces, and (2) confining boundaries. These mechanisms fundamentally differ from the effects of internal stresses and boundaries in equilibrium systems[17]. More closely related to our work are simulation studies of droplets containing active material that show tantalizingly life-like behaviors such as motility and division[51–54] These elegant studies highlight the importance of understanding the types of emergent behaviors that arise when active matter and deformable boundaries are combined. The continuum hydrodynamic theories employed in these works require key assumptions about the nature of particle organization and particle-membrane interactions

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