Evolution of avalanche conducting states in electrorheological liquids

TL;DR

This study investigates how charge transport and self-organization in electrorheological fluids lead to stable conducting chains, revealing avalanche dynamics and a critical transition to a stable pattern.

Contribution

It introduces an experimental analysis of avalanche behavior and proposes a simple evolution model based on maximum power principles in electrorheological liquids.

Findings

Avalanche size and duration follow a power-law distribution.

A sharp transition occurs at maximum power dissipation.

Self-organized criticality is observed in the system.

Abstract

Charge transport in electrorheological fluids is studied experimentally under strongly nonequlibrium conditions. By injecting an electrical current into a suspension of conducting nanoparticles we are able to initiate a process of self-organization which leads, in certain cases, to formation of a stable pattern which consists of continuous conducting chains of particles. The evolution of the dissipative state in such system is a complex process. It starts as an avalanche process characterized by nucleation, growth, and thermal destruction of such dissipative elements as continuous conducting chains of particles as well as electroconvective vortices. A power-law distribution of avalanche sizes and durations, observed at this stage of the evolution, indicates that the system is in a self-organized critical state. A sharp transition into an avalanche-free state with a stable pattern of conducting chains is observed when the power dissipated in the fluid reaches its maximum. We propose a simple evolution model which obeys the maximum power condition and also shows a power-law distribution of the avalanche sizes.