Spiral wave dynamics controlled by a square-shaped sensory domain

Spiral waves rotating rigidly in a thin layer of the light-sensitive Belousov–Zhabotinsky (BZ) reaction are subjected to a time-dependent uniform illumination. A non-local feedback algorithm computes the illumination intensity to be proportional to the average wave activity within a square-shaped sensory domain. The investigations show a broad spectrum of dynamical responses which results in square- and cross-shaped trajectories of the spiral tip, including reflections at the virtual walls. The geometry of the sensory domain is crucial in determining size and shape of the tip trajectories. A theoretical approach is proposed to explain the observed phenomena.