Abstract: The invention relates to an apparatus for producing a droplet assembly, which apparatus comprises: at least one droplet generator suitable for generating droplets of a viscous droplet medium; a droplet receiving region which is moveable relative to the at least one droplet generator; a temperature controller; and a control unit, which control unit is adapted to control the dispensing of droplets from the at least one droplet generator and the movement of the droplet receiving region relative to the at least one droplet generator, wherein the apparatus is adapted to produce a droplet assembly in the droplet receiving region, wherein the droplet assembly comprises a plurality of droplets, wherein each of said droplets comprises (i) a droplet medium, and (ii) an outer layer of amphipathic molecules around the surface of the droplet medium.