The electrowetting effect can change the shape of a liquid droplet on a surface by applying a voltage across the surface and droplet. Surface tension is a kind of measure of the energy required to maintain a certain drop shape, and that energy can be both chemical and electrical. In the video above, the droplet maintains a small contact area naturally (with no voltage). It expands and flattens under an electrical charge. Varying the voltage will change the degree to which the droplet flattens, but only to a point. Electrowetting is used to control variable lenses and some types of electronic displays. The technology may be used to replace current generation LCDs. (Video credit: V. Arya/Duke University)
Electrowetting
