Robust Chemical Circuits

TL;DR

This paper presents a novel design for chemical reaction network-based digital logic circuits that are inherently robust to various perturbations, with formal proofs and modular composition properties.

Contribution

It introduces catalytically read logic gates that eliminate the need for fanout, along with formal proofs of robustness and composability of the circuits.

Findings

All combinatorial circuits are robust to perturbations.

Several sequential circuits also exhibit robustness.

The robustness property is preserved under modular composition.

Abstract

We introduce a new motif for constructing robust digital logic circuits using input/output chemical reaction networks. These chemical circuits robustly handle perturbations in input signals, initial concentrations, rate constants, and measurements. In particular, we show that all combinatorial circuits and several sequential circuits enjoy this robustness. Our results complement existing literature in the following three ways: (1) our logic gates read their inputs catalytically which make `fanout' gates unnecessary; (2) formal requirements and rigorous proofs of satisfaction are provided for each circuit; and (3) robustness of every circuit is closed under modular composition.