Fabrication of Janus droplets by evaporation driven liquid-liquid phase separation

We present a universal and scalable method to fabricate Janus droplets based on evaporation driven liquid-liquid phase separation. In this work, the morphologies and chemical properties of separate parts of the Janus droplets can be flexibly regulated, and more complex Janus droplets (such as core-shell Janus droplets, ternary Janus droplets, and multiple Janus droplets) can be constructed easily. Janus droplets with complex compositions and morphologies were fabricated by co-solvent evaporation driven liquid-liquid phase separation.