Topology and Dynamics of Active Nematic Vesicles

TL;DR

This paper explores how active nematic materials within deformable vesicles exhibit complex, dynamic behaviors driven by activity, topology, and shape changes, revealing new states and mechanisms for biomimetic material design.

Contribution

It introduces the study of active nematic vesicles with shape-changing capabilities, demonstrating novel dynamical states influenced by topological constraints and activity.

Findings

Identification of a tunable periodic defect oscillation mode

Observation of shape-changing vesicles with streaming protrusions

Demonstration of topological constraints controlling active matter dynamics

Abstract

Engineering synthetic materials that mimic the remarkable complexity of living organisms is a fundamental challenge in science and technology. We study the spatiotemporal patterns that emerge when an active nematicfilm of microtubules and molecular motors is encapsulated within a shape-changing lipid vesicle. Unlike in equilibrium systems, where defects are largely static structures, in active nematics defects move spontaneously and can be described as self-propelled particles. The combination of activity, topological constraints and vesicle deformability produces a myriad of dynamical states. We highlight two dynamical modes: a tunable periodic state that oscillates between two defect configurations, and shape-changing vesicles with streaming filopodia-like protrusions. These results demonstrate how biomimetic materials can be obtained when topological constraints are used to control the non-equilibrium dynamics of active matter.