Membrane undulations in a structured fluid: Universal dynamics at intermediate length and time scales

TL;DR

This paper investigates the universal dynamics of membrane undulations within structured fluids, revealing a crossover from local to bulk behavior characterized by distinct power laws, relevant for various complex biological and soft matter systems.

Contribution

It introduces a generalized hydrodynamic framework for structured fluids, elucidating the crossover dynamics of membrane undulations and identifying universal power law regimes.

Findings

Universal power law behaviors in membrane dynamics within structured fluids

Identification of a crossover regime characterized by different universal power laws

Relevance of findings to biological membranes and soft matter systems

Abstract

The dynamics of membrane undulations inside a viscous solvent is governed by distinctive, anomalous, power laws. Inside a viscoelastic continuous medium these universal behaviors are modified by the specific bulk viscoelastic spectrum. Yet, in structured fluids the continuum limit is reached only beyond a characteristic correlation length. We study the crossover to this asymptotic bulk dynamics. The analysis relies on a recent generalization of the hydrodynamic interaction in structured fluids, which shows a slow spatial decay of the interaction toward the bulk limit. For membranes which are weakly coupled to the structured medium we find a wide crossover regime characterized by different, universal, dynamic power laws. We discuss various systems for which this behavior is relevant, and delineate the time regime over which it may be observed.