Heterogeneous response and non-Markovianity in the microrheology of semisolid viscoelastic materials

TL;DR

This paper uses numerical simulations to investigate how micro-heterogeneities in semisolid viscoelastic materials influence microrheological measurements, revealing deviations from Gaussian displacement distributions and providing analytical tools for characterization.

Contribution

It introduces a non-Markovian Langevin simulation approach to analyze the impact of micro-heterogeneities on microrheology, offering new analytical methods for material characterization.

Findings

Micro-heterogeneities affect mean squared displacement and shear moduli.

Displacement distributions deviate from Gaussian behavior due to heterogeneities.

Analytical characterization of micro-heterogeneities is achieved through microrheology.

Abstract

Recent works indicate that heterogeneous response and non-Markovianity may yield recognizable hallmarks in the microrheology of semisolid viscoelastic materials. Here we perform numerical simulations using a non-Markovian overdamped Langevin approach to explore how the microrheology experienced by probe particles immersed in an effective semisolid material can be influenced by its micro-heterogeneities. Our results show that, besides affecting the mean squared displacement, the time-dependent diffusion coefficient, and the shear moduli, the micro-heterogeneities lead to displacement distributions that deviate from the usual Gaussian behavior. In addition, our study provides an analytical way to characterize the micro-heterogeneities of semisolid viscoelastic materials through their microrheology.