Activatory coupling among oscillating droplets produced in microfluidic based devices

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.