Microfluidic Droplet Generator Device

In this work, two microfluidic droplet generator devices are developed and their potential applications are investigated. The first design refers to a single droplet generator and the second one refers to a multiple emulsion generator. In both cases, the diameter of the microchannels is designed to allow a continuous and homogeneous production of single droplets and double emulsions. The dimensions of the inner channels can be adjusted to precisely control droplet size and distance. By varying the flow rates, a dripping-to-jetting transition occurs and different combinations of emulsions with different applications can be created. The proposed designs are useful tools to separate droplets of different stiffness and sizes and for visualizing high-throughput samples. The single droplet generator device provides a quick way to study the effects of surfactants on droplet diameter, distance, jet length, and perturbation growth rate. The double emulsion generator device is a useful tool to study and visualize migration of crude oil droplets. It constitutes a qualitative novel method to control the configuration of compound drops by varying the flow rate. This affects the interfacial energies of multiple droplets and adjusts the value of the spreading coefficient. By varying the spreading coefficient, crude oil drops that initially are fully engulfed migrate and become partially engulfed. These devices also provide a platform to synthesize new composite materials. The droplets are polymerized by a UV-light source and later immersed in a matrix where their properties can be studied