Enhanced directionality of active processes in a viscoelastic bath

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 ( similar to 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.

Automated summary

Active fluctuations play an important role in the intracellular transport of passive objects, while the influence of viscoelasticity in shaping these processes is less understood. In a minimal experiment using a driven colloid in a viscoelastic bath, we found that viscoelasticity significantly increased the mean injected power to the passive object and reduced negative work fluctuations. These findings suggest an enhanced directionality in driven processes within a viscoelastic bath.