A waterfall display developed by Carnegie Mellon University presents multi-layered images on sheets of cascading water droplets.
Each screen is formed by water droplets falling from 50 stainless-steel needles. The needles release their droplets in unison, with 60 such lines created every second. A camera tracks their position and feeds the information to a projector, which illuminates them with pulses of light. The human eye integrates the information from several pulses to create the illusion of images moving on a floating screen.
Take a look at this very nicely prepared presentation video, explaining how the waterfall display works and showing some great sequences of water droplet display technology.
(Water droplet display video)
The display was created by Peter Barnum, Srinivasa Narasimhan and Takeo Kanade, all of CMU.
"A single projector, by quickly switching between images, can display on different layers at different times," says Barnum. "Anything you can have with a computer, like images, text, movies, or anything interactive, you can have on the drop display."
Technovelgy readers may recall some other refreshing displays created from water; take a dip in these links: