Running faster together: huge speed up of thermal ratchets due to hydrodynamic coupling

TL;DR

This study demonstrates that hydrodynamic coupling significantly enhances the speed of thermal ratchet motors, potentially impacting biological transport processes by increasing efficiency and causing aggregation.

Contribution

The paper introduces a particle-based simulation showing hydrodynamic coupling can boost thermal ratchet motor speeds by nearly two orders of magnitude.

Findings

Hydrodynamic coupling increases ratchet speed substantially.

Coupling leads to aggregate formation at longer times.

Enhanced efficiency in cargo transport due to correlated motion.

Abstract

We present simulations that reveal a surprisingly large effect of hydrodynamic coupling on the speed of thermal ratchet motors. The model that we use considers particles performing thermal ratchet motion in a hydrodynamic solvent. Using particle-based, mesoscopic simulations that maintain local momentum conservation, we analyze quantitatively how the coupling to the surrounding fluid affects ratchet motion. We find that coupling can increase the mean velocity of the moving particles by almost two orders of magnitude, precisely because ratchet motion has both a diffusive and a deterministic component. The resulting coupling also leads to the formation of aggregates at longer times. The correlated motion that we describe increases the efficiency of motor-delivered cargo transport and we speculate that the mechanism that we have uncovered may play a key role in speeding up molecular motor-driven intracellular transport.