# Information transmission and signal permutation in active flow networks

## TL;DR

This paper explores how active flow networks can transmit information differently from passive systems, revealing their potential for autonomous microfluidic devices and novel information processing capabilities.

## Contribution

It introduces a mathematical analogy with spin-ice models to analyze information transport in active flow networks, highlighting their unique properties and potential applications.

## Key findings

- Active flows preserve input information over longer distances.
- Active networks are highly sensitive to topological defects.
- Controlled permutations can be achieved through active matter dynamics.

## Abstract

Recent experiments show that both natural and artificial microswimmers in narrow channel-like geometries will self-organise to form steady, directed flows. This suggests that networks of flowing active matter could function as novel autonomous microfluidic devices. However, little is known about how information propagates through these far-from-equilibrium systems. Through a mathematical analogy with spin-ice vertex models, we investigate here the input-output characteristics of generic incompressible active flow networks (AFNs). Our analysis shows that information transport through an AFN is inherently different from conventional pressure or voltage driven networks. Active flows on hexagonal arrays preserve input information over longer distances than their passive counterparts and are highly sensitive to bulk topological defects, whose presence can be inferred from marginal input-output distributions alone. This sensitivity further allows controlled permutations on parallel inputs, revealing an unexpected link between active matter and group theory that can guide new microfluidic mixing strategies facilitated by active matter and aid the design of generic autonomous information transport networks.