Propagation of chemical waves across inexcitable gaps

The propagation of chemical reaction–diffusion waves across a sequence of gaps is studied experimentally using catalyst-printed membranes. We find that a wave fails to propagate across the entire reaction domain if the width W of a gap is greater than a critical value Wcr or if the spacing S between two successive gaps is less than a critical value Scr. For values of W ≪ Wcr and S ≫ Scr then successful propagation across the entire domain is highly probable, irrespective of the number of gaps. For values of W and S close to the critical values, the probability of failure increases with increasing number of gaps.