A team of UK researchers has successfully demonstrated a 3D holographic display that uses ultrasound to levitate and move 3D pixels.
Holograms have been a staple of science fiction for decades, and they're usually represented by a dimensional image made of light suspended in the air. Modern display technology typically projects 3D objects onto a 2D screen, and immersive display technologies such as VR or AR headsets track the user's head position to shift perspective and trick you into thinking the object exists in 3D space.
Now researchers from Sussex have now demonstrated an entirely new type of 3D display that isn't technically a hologram but is closer to that familiar sight from science-fiction. TheMultimodal Acoustic Trap Display uses two arrays of ultrasonic transducers to create a field of standing aucoustic waves in a 3D space, then uses those standing waves to levitate and manipulate a small polystyrene ball.
A computer controls the transducers to manipulate the field and move the polystyrene ball extremely quickly, while an LED is used to illuminate it. The ball then acts as a three-dimensional pixel in space, moving rapidly to create a three dimensional image. The ultrasonic speakers could also be used to play audible sound, and theoretically to provide tactile feedback.
Source: The Guardian
