The underwater acoustic hologram seen in the image projects a sound field towards a water
surface. A paper boat is propelled and pushed along the track that is generated by the hologram.
Credit: Kai Melde
3D-printed plastic blocks can now be turned into acoustic holograms that generate 3D shapes made of sound, which could function like sonic "tractor beams," according to a new study. This could lead to innovative ways to manipulate objects in midair without touching them, the researchers said.
This finding could also help scientists develop ultrasound therapies with sound fields sculpted to destroy unhealthy tissues in the body while leaving neighboring healthy cells intact, the researchers added.
Conventional holograms are a special kind of 2D photograph that, when lit up, essentially turn into windows onto 3D scenes. The pixels making up each hologram scatter light falling onto them in very specific ways, causing these light waves to interact with each other to generate an image with the illusion of depth. [10 Futuristic Technologies 'Star Trek' Fans Would Love to See] https://www.livescience.com/56202-3d-printed-acoustic-holograms.html
