Activatory Coupling Among Oscillating Droplets Produced in Microfluidic Based Devices
Federico Rossi, Aymen Zenati, Sandra Ristori, Jean-Marc Noël, Valérie Cabuil, Frédéric Kanoufi and Ali Abou-Hassan
In this paper we propose an experimental model able to catch the essential features of the propagation of chemical information in networks of micro-oscillators. In particular, we investigate the dynamics of the signal transmission/reception between water compartments containing an oscillating Belousov-Zhabotinsky (BZ) reaction, surrounded by an organic medium and further embedded in a polymer aqueous solution. By means of a microfluidic device we generated emulsions (droplets) stabilized by the presence of phospholipid monolayers at the interface. The oscillating dynamics of two neighbor droplets was studied by means of Space-Time plots and phase analysis, which showed that chemical communication led the system to an in-phase oscillating regime, suggesting an activatory type of coupling. In order to support this hypothesis, we performed numerical simulations of a simple model of two spatially homogeneous droplets coupled through the autocatalytic species HBrO2 (a BZ intermediate) and we found that in-phase oscillations represent the final stable attractor of the system.
Keywords: Coupled chemical oscillators, Belousov-Zhabotinsky reaction, microfluidics, activatory coupling, emulsions, phospholipid membranes