With the help of sound waves, scientists have already managed to make foam balls, drops of liquid and even pieces of cartilage grown in the laboratory literally float in the air. Scientists from the Universities of Sussex and Bristol went even further. They created a low-resolution display where normally indistinguishable squeaks took on "flesh" like levitating balls.
This technology is called JOLED. It uses polystyrene spheres (pixels) coated with titanium dioxide, which gives them an electrostatic charge.
An acoustic transducer system, consisting predominantly of miniature speakers located above and below the display, creates oppositely directed ultrasonic waves. They are inaccessible to human hearing, but strong enough to keep light pixels in the air.
By changing the intensity of the sound waves, you can make the pixel array move in the desired direction. So, for example, the rotation of pixels occurs due to the manipulation of the electric field of force surrounding the display. If you paint the sides of the pixels with different colors, then you will be able to create different color combinations when you rotate them.
“Traditionally, we thought of pixels as tiny colored squares on our screens, ” says Asier Marceau, a researcher at the University of Bristol. “JOLED breaks this stereotype by imagining pixels as balls floating in the air. In the future, we want to create complex three-dimensional changeable shapes out of them. "
In the near future, scientists plan to significantly increase the resolution of JOLED displays and begin using them in parks and art galleries.