# Transport of underdamped active particles in ratchet potentials

## TL;DR

This paper investigates how underdamped active particles move in asymmetric potentials, revealing that inertia can cause reversals in their preferred direction, enabling particle separation by tuning parameters.

## Contribution

It demonstrates that inertia induces ratchet effect reversals in active particles, allowing control over their transport direction, which was not observed in overdamped systems.

## Key findings

- Inertia causes ratchet effect reversals in active particles.
- Adjusting friction or propulsion can switch particle movement direction.
- Particles with different propulsion forces can be separated based on their transport behavior.

## Abstract

We study the rectified transport of underdamped active noninteracting particles in an asymmetric periodic potential. It is found that the ratchet effect of active noninteracting particles occurs in a single direction (along the easy direction of the substrate asymmetry) in the overdamped limit. However, when the inertia is considered, it is possible to observe reversals of the ratchet effect, where the motion is along the hard direction of the substrate asymmetry. By changing the friction coefficient or the self-propulsion force, the average velocity can change its direction several times. Therefore, by suitably tailoring the parameters, underdamped active particles with different self-propulsion forces can move in different directions and can be separated.