Sibeesh, P.Amrutha, S.V.Shajahan, T.K.2026-02-062022Springer Proceedings in Complexity, 2022, Vol., , p. 1311-131722138684https://doi.org/10.1007/978-3-030-99792-2_111https://idr.nitk.ac.in/handle/123456789/29861We report the experimental results of the effects of excitability on the wave characteristics of free rotating and pinned scroll rings in the Belousov-Zhabotinsky (BZ) reaction. The experiments show that the stability of the scroll ring depends on the excitability of the medium. At low excitability, the scroll ring becomes less stable and eventually breaks up. As we increase the excitability of the medium, the time period (T) and wavelength (λ ) of the excitation wave decrease while wave velocity (v) increases. Properties of both free and pinned scroll rings change in the same way. However, at a given excitability, both the λ and v of a pinned scroll ring increase with the size of the obstacle. For the range of parameters chosen in our experiments, the excitability changes brought by varying reactant concentrations have a higher impact on the scroll ring properties than those induced by the size of the pinning obstacle. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.BZ reactionExcitabilityPinningScroll wave