On micro-bead mechanics with actin filaments

TL;DR

This paper investigates how microscopic beads can be used to probe the mechanical properties of actin solutions, revealing size-dependent regimes and unexpected crystal-like responses at small scales.

Contribution

It demonstrates that the mechanical response of actin solutions varies with probe size, showing a transition to smectic crystal-like behavior in certain regimes.

Findings

Identification of multiple mechanical regimes based on probe size

Evidence of smectic crystal-like response in some conditions

Anomalous scaling of actin mechanics with particle size

Abstract

Experiments have been performed using microscopic beads to probe the small scale mechanics of actin solutions. We show that that there are a number of regimes possible as a function of the size of the probing particle. In certain cases we argue that the quasi-static response resembles a smectic crystal rather than an isotropic solid, implying an anomalous scaling of the mechanical response of actin solutions as a function of the size of the probing particles.