Self-sustained Molecular Rectification without External Driving or Information

TL;DR

This paper demonstrates a molecular rectification mechanism that converts thermal noise into directed motion without external energy or information, using intrinsic kinetic asymmetry at liquid-vapor interfaces.

Contribution

It introduces a novel rectification process driven solely by molecular kinetic asymmetry, challenging traditional energy-dependent models.

Findings

Intrinsic kinetic asymmetry sustains water flux

Surface energy is harvested during condensation

Rectification occurs without external energy input

Abstract

Rectifying thermal white noise into directed motion is generally believed to require the consumption of energy or information, as exemplified by Maxwell's demon-type feedback controllers. Here we demonstrate a molecular rectification mechanism that operates without any external energy or information flow. An ion-induced asymmetry between two liquid-vapor interfaces creates unequal surface barriers, enabling the harvesting and redistribution of surface energy released during condensation. Molecular dynamics simulations show that this intrinsic kinetic asymmetry sustains a persistent net water flux. Our results suggest that asymmetric potential energy landscape alone can rectify thermal fluctuations, revising the conventional understanding of noise-driven transport.