Perturbing dynamics of active emulsions and their collectives

Controlling fluidic flows in active droplets is crucial in developing intelligent models to understand and mimic single-celled microorganisms. Typically, these fluidic flows are affected by the interfacial dynamics of chemical agents. We found that these flows can be reconfigured by the mere presence of an anisotropic solid boundary embedded within active droplets. Spontaneous fluidic flows dynamically orient an embedded magnetic cluster, and the magnetic cluster, when realigned, causes these flows to reorient, thus providing control over the propulsion dynamics of chemotactic emulsions. When continuously perturbed, achiral emulsions exhibit emergent chiral motion with rotating fluidic flows. Such solid-fluid interactions occur in a number of self-propelling oil droplet systems, thereby enabling control over the emergent collective behaviors of chemically distinct active droplets.