Electrowetting is one of most popular method to control small droplets in miniaturized systems. Application area spans lap-on-a-chip for DNA and protein analysis to variable focus lens (liquid lens) for a camera module of a cellular phone. Especially, there is a tremendous need to develop an autofocus solution for a small camera module, as a high resolution image sensor (over 2M pixels) becomes available with relatively small optical format (about 1/3”). Such a small but high resolution senor is ready to be used for a cellular phone, which attract set-maker like Nokia and Samsung electronics to make a still camera-like phone of 10mm thickness. To meet the need, lens which can adjust a focal length by electrowetting is under development. In this talk, present effort to make a reliable liquid lens at Samsung Electro-mechanics will be summarized and the basic principle of electrowetting and its various application areas will be introduced. The contents of this talk can be categorized as follows: (i) introduction to a liquid lens and autofocus; (ii) introduction to electrowetting on dielectric; (iii) how to realize a liquid lens for a camera module; (iv) what to do.