Effect of concentration gradient on spiral wave dynamics in the Belousov–Zhabotinsky reaction system†

The oscillatory Belousov–Zhabotinsky (BZ) reaction is often used for the study of rotating spiral waves that are responsible for life-threatening cardiac arrhythmia. In this work, we explore the influence of a concentration gradient on the dynamics of spiral waves in the BZ-reaction system. Using ion-exchange resin beads, we introduce a gradient of hydrogen ions in a thin layer of BZ gel hosting a spiral wave. By monitoring the drift of the spiral tips from their initial position, we show that a gradient of hydrogen-ions can manoeuvre the position of the spiral. The magnitude of the drift is found to depend on the gradient strength and relative position of the spiral from the resin beads. Our experimental study is supported with numerical simulations carried out on a modified Oregonator model that we have developed from the Field, Körös, Noyes mechanism of the BZ.