Lea Laetitia Pontani (INSP) - The many faces of emulsion droplets

Emulsions are a model system for jammed matter but can also be used for the synthesis of adhesive and patchy particles. For example the interactions between the droplets are tuned through depletion to sample different packing configurations and build a statistical mechanics framework for jammed matter. Additionally we can mimic the manifold interactions found in living systems and mediate particle-particle interactions with biological molecules. To this aim we produce bio-inspired emulsions where the droplets reproduce specific cellular functions such as lipid domain formation, cell-cell adhesion or even hemifusion. For example, immiscible lipids on the surface of emulsion droplets create stable domain patterns, which provides a route for patchy particle synthesis. Functionalizing the patches with binders would thus allow the droplets to aggregate with a given geometry. In addition to this we use DNA binders to introduce reversible adhesion between the droplets, which is a prerequisite for the self-assembly of mesoscopic structures with well defined optical or mechanical properties. In particular we control the number of binders in this system in order to assemble linear chains of thermal droplets or compact structures with higher valency. Bio-inspired emulsions are therefore a useful system to answer questions from a biophysics perspective, but also provide a new class of tunable liquid particles for self-assembly.