Enhanced directionality of active processes in a viscoelastic bath

TL;DR

This study demonstrates that viscoelastic environments significantly enhance the directionality and power of active processes, reducing negative work fluctuations, as shown through experiments with driven colloids in a viscoelastic bath.

Contribution

It provides experimental evidence that viscoelasticity increases injected power and reduces fluctuations, revealing new insights into active transport in complex environments.

Findings

Viscoelasticity increases mean injected power by ~50%.

Negative work fluctuations are notably reduced.

Enhanced directionality in driven processes within viscoelastic media.

Abstract

Active fluctuations are known to play a significant role in the intracellular transport of passive objects. However, the effect of viscoelasticity of the environment in shaping such processes is relatively less understood. Here, with a minimal experiment using a driven colloid in a viscoelastic bath, we show that viscoelasticity significantly increases the mean injected power to the passive object ($\sim 50\%$ compared to a viscous medium), for the same strength of the external driving. Additionally, we observe a notable reduction in negative work fluctuations across a wide range of driving amplitudes. These findings collectively suggest an enhanced directionality in driven processes within a viscoelastic bath, which we attribute to the emergence of interactions between the colloid and the viscoelastic medium.