Modeling, simulation and experimentation of droplet-based microfluidic networks

The aim of this paper is to model the "macroscopic" functioning of droplet-based microfluidic networks, i.e., the speed and trajectory of droplets across a network of microfluidic elements. To this end, we first give a quick overview of microfluidic basics and main governing rules. Based on such principles, we derive mathematical models of the fundamental components of a microfluidic network and, then, we identify the set of variables that capture the dynamic state of the system. This allows us to define a simple way to simulate the "macroscopic" evolution of the microfluidic network, predicting the path followed by the droplets in the circuits. To validate the model, we compare the simulation results with the experimental outcomes we obtained from a simple but representative microfluidic circuit, which has been realized in our laboratory, and with other circuits tested in previous works. Finally, we apply our theoretical model to a more complex use-case, consisting in a microfluidic network with bus topology, and we draw some final considerations about the performance of such a network.