Engineers Create Floating Pixels with Soundwaves and Force Fields

JOLED uses ultrasound to turn tiny, multi-colored spheres into pixels for floating displays.

The pixels are levitated using a series of miniature ultrasound speakers that create high-pitched and high-intensity soundwaves that are inaudible but forceful enough to hold the spheres in place. They can be spun and flipped using electric force fields. (Image courtesy of Sri Subramanian/University of Sussex.)

The pixels are levitated using a series of miniature ultrasound speakers that create high-pitched and high-intensity soundwaves that are inaudible but forceful enough to hold the spheres in place. They can be spun and flipped using electric force fields. (Image courtesy of Sri Subramanian/University of Sussex.)

Researchers at the Universities of Sussex and Bristol have used soundwaves to lift many tiny objects at once before spinning and flipping them using electric force fields.

The technology—called JOLED—effectively turns tiny, multi-colored spheres into real-life pixels, which can form into floating displays or bring computer game characters to life as physical objects.

The research opens up new possibilities for mobile and game designers, giving them a new way of representing digital information in a physical space.

“We’ve created displays in mid-air that are free-floating, where each pixel in the display can be rotated on the spot to show different colours and images,” said Sriram Subramanian, a professor in the University of Sussex’s school of engineering and informatics and head of lab behind the research. “This opens up a whole new design space, where computer and mobile displays extend into the 3D space above the screen.”

The pixels are levitated using a series of miniature ultrasound speakers that create high-pitched and high-intensity soundwaves that are inaudible but forceful enough to hold the spheres in place.

A thin coating of titanium dioxide gives the pixels an electrostatic charge, enabling them to be manipulated in mid-air by changes to an electric force field, created by tiny electrodes.

“The most exciting part of our project is that we can now demonstrate that it is possible to have a fully functioning display which is made of a large collection of small objects that are levitating in mid-air,” said Deepak Sahoo, research associate in human-computer interaction at the University of Sussex. “JOLED could be like having a floating e-ink display that can also change its shape.”

This is the first to demonstrate such a fine level of control over these levitating pixels, moving the technology closer to something that might soon be part of theme parks or galleries.

As examples, the researchers suggested that in the future, such a display could be placed in a public park to show to users the complex and changing patterns of carbon footprints of different countries or currency fluctuations in different regions of the world.

“Traditionally, we think of pixels as tiny colour-changing squares that are embedded into our screens. JOLED breaks that preconception by showing physical pixels that float in mid-air,” explained Asier Marzo, research associate in the department of mechanical engineering at the University of Bristol. “In the future we would like to see complex three-dimensional shapes made of touchable pixels that levitate in front of you.”

“In the future we plan to explore ways in which we can make the display multi-coloured and with high colour depth, so we can show more vivid colours,” Subramanian added.

“We also want to examine ways in which such a display could be used to deliver media on-demand. A screen appears in front of the user to show the media and then the objects forming the display fall to the ground when the video finishes playing.”

For more news on the future of display technology, find out why holographic displays just got a lot better with nano-magnetic pixels.