Power-Efficiency Constraint for Chemical Motors

TL;DR

This paper derives a fundamental power-efficiency constraint for chemically fueled microscopic rotary engines, revealing that maximum power efficiency is half of the quasi-static limit, aiding understanding and design of biological and synthetic chemical motors.

Contribution

It introduces a new thermodynamic constraint relation between power and efficiency for chemical motors, specifically for steady-state rotary engines like ATPase.

Findings

Efficiency at maximum power is half of the quasi-static efficiency.

Derived a power-efficiency constraint relation for chemical engines.

Insights applicable to natural and artificial microscale engines.

Abstract

Chemical gradients provide the primordial energy for biological functions by driving the mechanical movement of microscopic engines. Their thermodynamic properties remain elusive, especially concerning the dynamic change in energy demand in biological systems. In this article, we derive a constraint relation between the output power and the conversion efficiency for a chemically fueled steady-state rotary motor analogous to the $\mathrm{F}_o$ motor of ATPase. We find that the efficiency at maximum power is half of the maximum quasi static efficiency. These findings shall aid in the understanding of natural chemical engines and inspire the manual design and control of chemically fueled microscale engines.