Chemical Instability Induced by an Electric Field

Abstract

In a quasi-one-dimensional reaction−diffusion−migration system based on the methylene blue−sulfide−oxygen oscillatory reaction in a matrix of polyacrylamide gel, almost stationary patterns are observed. A weak electrical field applied to the system induces waves which travel toward the cathode. Close to the anode, the initially observed stationary pattern remains stable. In some experiments, a lateral instability of the wave front is also observed. The spatio−temporal dynamics is analyzed by the Karhunen−Loeve decomposition technique, and entropy-like quantities are used to describe the dynamics. Numerical simulations based on a chemically realistic model confirm the experimental observations.

Spatio-temporal Pattern Formation in Chemical Reactions

“…The onset of waves occurs via a saddle-node bifurcation as was demonstrated by numerical continuation [3]. Similar behaviour has recently been observed in a chemical experiment [4].…”

Voltage-Induced Wrinkle Performance in a Hydrogel by Dielectric Elastomer Actuation

“…Yet, an electrically activated hydrogel is more favorable. Owing to the ions in hydrogel, directly applying voltage on hydrogel may cause a local chemical instability or even breakdown [15]. So in this study, we present a new actuation route for the hydrogel via the electromechanical deformation of a dielectric elastomer.…”

Applications of the Karhunen-Loève Decomposition to Quantum Dynamical Problems

“…Recently, the KL-decomposition has been applied to analyze field-induced chemical waves [4], for the modal control of spatiotemporal chaos [5,6] and in hydrodynamics [7]. In these applications, however, a real function was decomposed into empirical eigenmodes; the use of the KL-decomposition in quantum dynamics requires an extension of the method to general complex valued functions.…”