"The first liquid camera lens with no moving parts, and that can switch between two levels of magnification, has been designed by a German research team. The work is an important step towards liquid zoom lenses that can sweep through a range of magnifications.Smaller and cheaper than conventional lenses, they have yet to achieve the zoom magnification of traditional lenses. However, Samsung has been using liquid lenses in some of their cellphones since 2004.
Liquid lenses bend light using the curved boundary between watery and oily liquids. When the two liquids are held in the right container, the boundary between them can be made to curve in a way that focuses light simply by applying a voltage."