Modeling of Droplet Speed Shift Keying in Microfluidic Communications

Droplet microfluidics is a research area rapidly evolving due to its vast range of potential applications in several fields ranging from medicine to biodefense, and drug administration. In this context, it is crucial to identify efficient and effective methods for communicating by means of droplets. Various techniques have been proposed in the past to encode data by exploiting droplets, such as utilizing droplet size, droplet composition, or the presence/absence of droplets. Nevertheless, these methods are plagued by propagation delays within the channel, resulting in the impossibility to rapidly deliver information at the receiver. To address this issue, this paper introduces a novel methodology for encoding information. The proposed approach involves the instantaneous manipulation of a train of dye drops within a continuous oil phase to induce variations in flow properties. By capitalizing on the stable and laminar flow of the drops, our objective is to encode data instantaneously by altering the dye-oil pressure pairs. To better predict and explain the microfluidic dynamics in the channel, we develop a model of the proposed scheme.