Hidden energy flows in strongly coupled nonequilibrium systems

TL;DR

This paper develops a thermodynamically consistent framework to quantify hidden energy flows in strongly coupled nonequilibrium nanoscale systems, aiding understanding of biological machines and their energy dynamics.

Contribution

It introduces a novel theory and phenomenological approach to measure hidden excess power in autonomous systems, validated through numerical simulations.

Findings

The theory accurately predicts hidden energy contributions.

Numerical simulations confirm the framework's validity.

Provides insights into energy flows in molecular and rotary motors.

Abstract

Quantifying the flow of energy within and through fluctuating nanoscale systems poses a significant challenge to understanding microscopic biological machines. A common approach involves coarse-graining, which allows a simplified description of such systems. This has the side effect of inducing so-called hidden contributions (due to sub-resolution dynamics) that complicate the resulting thermodynamics. Here we develop a thermodynamically consistent theory describing the nonequilibrium excess power internal to autonomous systems, and introduce a phenomenological framework to quantify the hidden excess power associated with their operation. We confirm our theoretical predictions in numerical simulations of a minimal model for both a molecular transport motor and a rotary motor.