New systems for pattern formation studies

Abstract

Recent years have witnessed remarkable developments in the study of spatial pattern formation in reaction-diffusion systems. One of the most notable achievements has been the discovery of Turing patterns in the chlorite-iodide-malonic acid (CIMA) system. We have developed a mechanism for the chemistry of that system and from that mechanism have derived: (a) an understanding of how the Turing patterns arise; (b) a simple two-variable model, amenable to analytic study, that reproduces both the homogeneous behavior of the system and the Turing patterns; and (c) a general approach to the design of new systems that will show Turing patterns. We present experimental results of Turing patterns in the chlorine dioxide-iodine-malonic acid system, which our mechanistic analysis suggests lies at the heart of the CIMA Turing patterns. We also discuss, using the example of traveling waves in the Belousov-Zhabotinsky reaction, another experimental configuration, a sol-gel glass impregnated with key reagents, that shows great promise for the study of pattern formation and wave behavior.