Abstract
Synchronization is the process when two interacting periodic rhythms adopt the same\r frequency. This can be determined by the strength of the interactions between the rhythms in\r what is known as coupling. The type of coupling and its strength can determine the ratio of\r frequencies between the two interacting rhythms or oscillators, which can be a ratio of\r integers. Synchronization is widely found in nature. For instance, it can be found in neural net\r communication and in the generation of heart beats. These natural systems can be mimicked\r by synthetic systems. One example is self-oscillating gels, which are polymer networks with a\r metal catalyst covalently bonded into the polymer chain. This catalyst can participate in a\r chemical reaction. In doing so, these gels, arranged spatially nearby one another, can have the\r capability of communicating with each other through the diffusion of chemical species. Thus,\r these gels can synchronize their oscillations and produce different oscillating patterns\r depending on the coupling strength. In groups of self-oscillating gels participating in the\r v\r Belousov-Zhabotinsky (BZ) reaction, it has been found that the gel volume, inter-gel distance,\r and the concentration of the metal catalyst dictate which gel acts as the pacemaker or leading\r gel of an oscillatory cycle. This work seeks to understand which of these factors prevail in\r leading the oscillatory cycle when all factors are present simultaneously and if perturbations\r using light can cause changes in the synchronization of these gels. For this purpose, we\r synthesized and prepared cubic self-oscillating BZ gels with a ruthenium (II/III) complex catalyst,\r and immersed them into a solution of BZ reactants. Here, four gels were arranged spatially at\r the corners of a square and oscillation patterns were observed. In some experiments, the\r perturbation of the four gel synchronization was induced by irradiating the gels with high\r intensity light. Our results show that in conditions of strong coupling, the group of gels\r oscillates almost simultaneously. We also found that the inter-gel distance factor prevails over\r the tendency of the smallest gel to behave as the leading oscillator. In symmetric\r configurations, where volumes and inter-gel distances are equal to one another, anti-clockwise\r oscillation patterns can be observed. When light is used to perturb the system, we find that it\r induces a change in the frequency ratio of the oscillators and can ‘reset’ oscillation patterns. In\r short, it can change the preexisting oscillation patterns.