Interestingly, oil-free double emulsions can also be produced from water/water emulsions, either by microfluidics, or by osmose-induced reverse diffusion of water in polymer-rich droplets . For instance, a droplet made of a mix of miscible pair of PEG and dextran (both at relatively low concentration) dispersed in a continuous phase containing PEG at higher concentration induces diffusion of water from the inner droplet to the more concentrated PEG outer continuous phase. This increases the concentration of both polymers PEG and Dextran in the droplet, which further phase separate, forming a 'water (PEG)'-in-'water (Dextran)'-in-'water (PEG)' double aqueous emulsion. Higher order aqueous emulsions can also be produced by this way .