Fluid Networks Assembled from Endoskeletal Droplets

Anisotropic endoskeletal droplets are produced continuously in a microfluidic device. The device temperature is controlled such that droplets are formed in a fluid state and subsequently cooled to crystallize an internal network that retains an anisotropic shape. Droplets that are forced to collide after crystallizing partially coalesce to form linear droplet superstructures with tunable rigidity. Superstructure filaments can be folded into larger, three-dimensional percolating fluid networks with tunable porosity and size, which can be further controlled by temperature. The results of this work provide a means of generating hierarchical porous structures with continuous liquid interfaces on demand in a process similar to three-dimensional printing.