The metamaterial device is set up for testing in front of a sound-absorbing wall so that
reflecting sound waves do not affect the experiments.
Credit: Duke University
3D-printed bricks that look like Lego pieces could provide a simple, low-cost way of creating acoustic holograms — 3D shapes and structures made of sound — for applications as varied as entertainment, medicine or wireless charging, according to a recent study.
Anyone who's watched "Star Wars" will be familiar with the concept of an optical hologram — a 3D image that floats in midair — though real-life technology is significantly less advanced than what was portrayed on-screen.
Holograms are effectively a recording of a 3D light field that can project a reproduction of the original object when lit properly. (The term hologram can refer to both the recording medium and the resulting projection.) The hologram concept can be applied to sound waves to create acoustic holograms, though this field of research is still very new, according to the scientists who developed this new method. [10 Futuristic Technologies 'Star Trek' Fans Would Love to See] https://www.livescience.com/56735-3d-printed-bricks-create-acoustic-holograms.html
