Active Refrigerators Powered by Inertia

TL;DR

This paper introduces a novel active refrigerator concept that leverages inertial effects in active Brownian particles to achieve significant local cooling, potentially enabling environmental toxin removal without isolating barriers.

Contribution

It proposes a new operational principle for active refrigerators based on inertial active Brownian particles and their phase behavior, a previously unexplored approach.

Findings

Achieves two orders of magnitude temperature reduction

Utilizes motility-induced phase separation in the cooling regime

Operates without isolating walls, enabling environmental applications

Abstract

We present the operational principle for a refrigerator which uses inertial effects in active Brownian particles to locally reduce their (kinetic) temperature by two orders of magnitude below the environmental temperature. This principle exploits the peculiar but so-far unknown shape of the phase diagram of inertial active Brownian particles to initiate motility-induced phase separation in the targeted cooling regime only. Remarkably, active refrigerators operate without requiring isolating walls opening the route towards using them to systematically absorb and trap, e.g., toxic substances from the environment.