New Technology Turns Water Drops into 3-D Display

A new display “screen” made out of water droplets creates 3-D images that can be viewed without special glasses.

The new technology involves flashing images from a projector onto the display. But instead of pixels, this display is made out of layers of falling water droplets, which are precisely controlled to create 3-D images. The more layers of falling water, the higher the resolution.

“There is nothing special about the particular projector we are using,” said Srinivasa Narasimhan, a professor at Carnegie Mellon University, who helped develop the display. “Our technology controls the drop layers so that when the projector switches an image it follows the pattern of drops, lighting them up as they fall." [Read "10 Profound Innovations Ahead."]

Narasimhan developed the water-display with Takeo Kanade, also a professor at Carnegie Mellon, and Peter Barnum, a student at the university.

“Our dream is to scale this display to the size of a large room,” Narasimhan said. “Then we will have created a truly immersive visual experience for users … [like] the Holodeck in ‘Star Trek,’” Narasimhan said.

They researchers say they hope to achieve this within a decade.

Projecting light onto water

So far the team has built a prototype with a front viewing “screen” about the size of a 12-inch laptop. And while they could commercialize the device as-is, to make it a competitive home-use product the researchers need to achieve higher resolution, Narasimhan said.

To build the 3-D water-display, the researchers created a computer-controlled manifold that released each layer of drops in such a way that the drops in the front row don’t block the back rows, and vice versa. A camera tracked the position of the drops so that the projector could target each row independently.

“At each time instant, the projector shines part of each image on each layer,” Barnum said. “Because the projector switches images so fast, it appears that the projector is shining on all layers simultaneously, Barnum said.

No glasses required

And because water refracts, or bends, light and the drops are spherical, the images can be seen from any angle – unlike a computer screen, where the image is obscured from side angles and not seen from the back.

“Our display does not require any glasses and can be seen from all angles, whereas 3-D movies need glasses and not all seating positions are ideal,” Narashimhan said.

In addition to the 3-D effect, the display is also interactive. When viewers touch the water drops, they alter the image appearance.

The researchers have given the “screen” several test-drives by using it to display video images and texts, as well as simulations of fish swimming in an aquarium, and a 3-D version of the video game Tetris.

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