Experimental implementation of collision-based gates in Belousov–Zhabotinsky medium

We experimentally demonstrate that excitation wave-fragments in a Belousov–Zhabotinsky (BZ) medium with immobilised catalyst can be used to build elementary logical gates and circuits. Following our previous theoretical constructions [Adamatzky A. Collision-based computing in Belousov Zhabotinsky medium. Chaos, Solitons & Fractals 2004;21:1259–64] on embedding logical schemes in BZ medium, we represent True/False values of logical variables by presence/absence of wave-fragments. We show that when wave-fragments collide with each other they may annihilate, fuse, split and change their velocity vectors. Thus the values of logical variables represented by the wave-fragments change and certain logical operations are implemented. In the paper we provide examples of experimental logical gates, and present pioneer results in dynamic, architectureless computing in excitable reaction–diffusion systems.