‘Invisibility cloak’ material bends and shapes sound
27 Feb 2017
Scientists at the universities of Bristol and Sussex have created a metamaterial that bends, shapes and focuses the sound waves that are passed through it.
Metamaterials are designed to perform “nature-defying” tasks. In 2015 scientists created “a real-life invisibility cloak” which completely hides small objects.
The material created by the Bristol and Sussex team could be used to transform medical imaging and personal audio equipment, the researchers said.
It consists of layers of “small bricks” that each coil up space, which acts to slow down sound, meaning that incoming sound waves could be transformed into any required sound field, the team added.
Gianluca Memoli, from the Interact Lab at the University of Sussex, said: "Our metamaterial bricks can be 3D-printed and then assembled together to form any sound field you can imagine.
“We also showed how this can be achieved with only a small number of different bricks. You can think of a box of our metamaterial bricks as a do-it-yourself acoustics kit.”
The researchers said there could be “many exciting” applications of this technology in the future.
Bruce Drinkwater, professor of ultrasonics at the University of Bristol, said: "We are now working on making the metamaterial layers dynamically reconfigurable. This will mean we can make cheap imaging systems which could be used either for medical diagnostics or crack detection."
A full account of the research has been published in the journal Nature Communications.
