Localized chemical wave emission and mode switching in a patterned excitable medium

Chemical waves are initiated from complex geometries in the excitable Belosouv-Zhabotinsky medium using a wet stamping technique. Because of the coupling between the system's chemical kinetics and geometry, waves are emitted only from selected locations. By varying the nature of the wave-triggering reagent (here formaldehyde or methanol), it is possible to switch between two spatially distinct modes of wave emission. The system's dynamics is studied numerically, and the results of modeling agree with experimental observations.