Human organs, circus animals, and even long-dead musicians have all appeared in holograms.
But now, scientists at the University of Sussex have discovered a technique to make advanced holograms that you can not only see, but also hear, and even feel – and they accomplished it by using some old technology.
On Wednesday, the researchers published a paper in the journal Nature describing their gadget, which they refer to as the Multimodal Acoustic Trap Display (MATD).
A two millimeter-wide polystyrene bead is captured and moved around by the device utilising ultrasonic waves. While red, green, and blue LEDs illuminate it, the bead draws out the shape of an item in three dimensions.
The human eye only notices the finished shape because the bead is moving so quickly, creating a convincing illusion similar to how a quick succession of still images can give the impression of movement.
Our new technique is influenced by vintage televisions, which employ a single colour beam that moves so swiftly across the screen that your brain perceives it as a single image “Ryuji Hirayama, a researcher, stated in a press statement. “Our prototype achieves the same thing by using a coloured particle that is capable of moving so swiftly throughout 3D space that a volumetric image may be seen in midair to the unaided eye.
The device uses ultrasonic waves to generate both an auditory noise and a tactile sensation.
According to the researcher Diego Martinez Plasencia, ultrasonography is still a mechanical wave that transmits energy through the air even when it is not audible to humans. “Our prototype concentrates and directs this energy, which can then excite your skin to feel good or your ears for audio.”
The gadget may eventually use many beads to produce even more intricate holograms, according to the researchers. The idea that, in contrast to many cutting-edge technologies, this one might not have too much trouble making the transition to a consumer product is arguably even more fascinating than the prototype itself.
Hirayama stated in the press announcement that “the MATD was constructed using low-cost and commercially accessible components.” We think there is lots of room to raise its potential and capacity.
