Adaptive machine and its thermodynamic costs

TL;DR

This paper models an adaptive machine inspired by inhomogeneous catalysis, demonstrating how it optimally adjusts to changing chemical potentials within thermodynamic constraints, resembling biological features.

Contribution

It introduces a minimal thermodynamic model for an adaptive particle transfer machine that self-tunes to maximize current under variable conditions, incorporating energy storage and structural fluctuations.

Findings

The machine can adapt to changing chemical potentials while respecting thermodynamic limits.

Stored energy (negative temperature) enables structural adaptation.

Structural fluctuations are controlled by the stored energy, affecting machine malfunction rates.

Abstract

We study the minimal thermodynamically consistent model for an adaptive machine that transfers particles from a higher chemical potential reservoir to a lower one. This model describes essentials of the inhomogeneous catalysis. It is supposed to function with the maximal current under uncertain chemical potentials: if they change, the machine tunes its own structure fitting it to the maximal current under new conditions. This adaptation is possible under two limitations. (i) The degree of freedom that controls the machine's structure has to have a stored energy (described via a negative temperature). The origin of this result is traced back to the Le Chatelier principle. (ii) The machine has to malfunction at a constant environment due to structural fluctuations, whose relative magnitude is controlled solely by the stored energy. We argue that several features of the adaptive machine are similar to those of living organisms (energy storage, aging).