Collision-based computing in Belousov-Zhabotinsky medium

A photosensitive sub-excitable Belousov-Zhabotinsky medium exhibits propagating wave fragments that preserve their shapes during substantial periods of time. In numerical studies we show that the medium is a computational universal architectureless system, if presence and absence of wave fragments are interpreted as truth values of Boolean variable. When two or more wave fragments collide they may annihilate, fuse, split or deviate from their original paths, thus values of the logical variables are changed and certain logical gates are realized in result of the collision. We demonstrate exact implementation of basic operations with signals and logical gates in Belousov-Zhabotinsky dynamic circuits. The findings provide a theoretical background for subsequent experimental implementation of collision-based, architectureless, dynamical computing devices in homogeneous active chemical media. (C) 2004 Published by Elsevier Ltd.