“What we’ve been trying to create is a method for making free-floating objects act as a display,” Sriram Subramanian, a professor in the University of Sussex’s School of Engineering and Informatics, told Digital Trends. “That could be sand, dust, or particles, which can be made to float up in the air, and either have information projected on them or be made to act as sources of visual content. The first step in that progression is proving that we can float multiple objects at the same time, and change the orientation of those objects so that they face a certain way. That’s what we’ve done here.”
The levitation process is carried out using sound waves created by miniature ultrasound speakers; inaudible to the human ear, but powerful enough to hold the tiny spherical “pixels” in place. The pixels carry an electrostatic charge, courtesy of a thin coating of titanium dioxide, which allows them to be manipulated in midair with the aid of tiny electrodes.
Subramanian said that a useful application for the floating display would be “large-scale physical installations in parks and science museums.” It will, he suggested, “be possible to have floating interactive displays capable of showing data.”
In the future, he further asserted, it is likely that similar technology will make it possible to display complex three-dimensional shapes composed of touchable pixels that levitate in front of users.
“Right now, I think it would possible to create a 4K resolution,” Subramanian said. “However, the resolution isn’t the only thing to consider; there’s also the number of pixels per inch. At present we’d struggle to beat the pixel density of current LCD displays. It’s possible to have a denser pattern of pixels with the levitation system, but that’s going to require some work — like changing the frequency the soundwaves operate at.”
