Ratchet effect driven by Coulomb friction: the asymmetric Rayleigh piston

TL;DR

This paper demonstrates how Coulomb friction can induce a ratchet effect in a Brownian particle, with analytical and numerical analysis showing the role of friction and lack of equipartition in generating directed motion.

Contribution

It provides an analytical expression for the average velocity of an asymmetric Rayleigh piston influenced by Coulomb friction, highlighting a novel friction-driven ratchet mechanism.

Findings

Coulomb friction induces a ratchet effect in the piston.

Analytical expression for piston velocity in the rare collision limit.

Numerical simulations support the analytical results.

Abstract

The effect of Coulomb friction is studied in the framework of collisional ratchets. It turns out that the average drift of these devices can be expressed as the combination of a term related to the lack of equipartition between the probe and the surrounding bath, and a term featuring the average frictional force. We illustrate this general result in the asymmetric Rayleigh piston, showing how Coulomb friction can induce a ratchet effect in a Brownian particle in contact with an equilibrium bath. An explicit analytical expression for the average velocity of the piston is obtained in the rare collision limit. Numerical simulations support the analytical findings.