Microrheology of semiflexible filament solutions based on relaxation simulations

TL;DR

This paper introduces an efficient computational approach using relaxation simulations and the fluctuation-dissipation theorem to evaluate the viscoelastic properties of dilute semiflexible filament solutions, validated against experimental data.

Contribution

It presents a novel, low-cost simulation method for microrheology of semiflexible filaments based on relaxation dynamics and an effective medium model.

Findings

Accurately predicts complex shear modulus and viscosity from relaxation simulations.

Validates the methodology with experimental data on DNA and collagen solutions.

Shows the impact of bending energy on viscoelastic behavior.

Abstract

We present an efficient computational methodology to obtain the viscoelastic response of dilute solutions of semiflexible filaments. By considering an approach based on the fluctuation-dissipation theorem, we were able to evaluate the dynamical properties of probe particles immersed in solutions of semiflexible filaments from relaxation simulations with a relatively low computational cost and higher precision in comparison to those based on stochastic dynamics. We used a microrheological approach to obtain the complex shear modulus and the complex viscosity of the solution through its compliance which was obtained directly from the dynamical properties of a probe particle attached to an effective medium described by a mesoscopic model, i.e., an effective filament model (EFM). The relaxation simulations were applied to assess the effects of the bending energy on the viscoelasticity of semiflexible filament solutions and our methodology was validated by comparing the numerical results to experimental data on DNA and collagen solutions.