Efficient transport controlled by biharmonic frictional driving

TL;DR

This paper demonstrates that with precise control of biharmonic oscillations, dry friction-driven transport can sustain finite efficiency regardless of input energy, challenging previous assumptions about saturation effects.

Contribution

It introduces a minimal friction model explaining drift velocity dependencies and extends to efficiency estimates for various periodic excitations.

Findings

Finite transport efficiency maintained at high input energies.

Biharmonic oscillations enable controlled mass transport.

Model accurately predicts drift velocity and efficiency.

Abstract

Dry friction has been proposed as a rectifying mechanism allowing mass transport over a vibrating surface, even when vibrations are horizontal and unbiased. It has been suggested that the drift velocity will always saturate when the energy of the input oscillation increases, leading to a vanishing efficiency that would hinder the applicability of this phenomenon. Contrary to this conjecture, in this work we experimentally demonstrate that, by carefully controlling the forcing oscillations, this system can maintain a finite transport efficiency for any input energy. A minimal friction model explains the observed dependencies of the drift velocity on the signal parameters in the case of biharmonic base oscillations, which can be extended to obtain efficiency estimates for any periodic excitation.