‘Floating pixels’ render digital information in a physical space

Researchers have used sound waves to lift objects simultaneously before spinning and flipping them using electric force fields, a development that could render digital information in a physical space.

Developed at the Universities of Sussex and Bristol, the so-called JOLED technology turns tiny, multi-coloured spheres into pixels that can form into floating displays or bring computer game characters to life as physical objects.

Prof Sriram Subramanian, from Sussex University’s School of Engineering and Informatics, is the head of lab behind the research.

“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,” he said. “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.

Dr Deepak Sahoo, Research Associate in Human-Computer Interaction at Sussex University, said: “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.

“JOLED could be like having a floating e-ink display that can also change its shape.”

The paper is said to be the first to demonstrate such a fine level of control over these levitating pixels, moving the technology closer to utilisation.

Asier Marzo, research associate in the Department of Mechanical Engineering at Bristol University said: “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.

“In the future we would like to see complex three-dimensional shapes made of touchable pixels that levitate in front of you.”

Prof Subramanian added: “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.

“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.”