Producing a vesicle, comprises: (a) providing a fluid (1), which comprises at least one amphiphilic substance and (b) generating a flow of the fluid in at least one flow chamber (19), where the flow comprises at least an extensional flow proportion at least in a partial area of the flow chamber that causes the formation of vesicle from the fluid. An independent claim is also included for a device for producing the vesicle by the above method and/or dispersing, de-agglomerating, mixing and/or emulsifying the fluid, comprising at least one pair of rotating rollers (21), respectively with a cylindrical shell-shaped rolling surface, where the flow chamber is formed for the fluid between the rollers, and at least one of the rollers exhibits a cavity, where the rolling surface of this roller exhibits at least one inlet opening, through which the fluid of the flow chamber flows into the cavity.
