Researchers from the universities of Sussex and Bristol, in England, have invested a new material capable of bending and focusing sound waves.
The super-material is the latest addition to a group of groundbreaking metamaterials — a class of materials designed to manipulate our physical reality. Scientists have previously designed invisibility cloaks using metamaterials that capture lightwaves.
Precisely shaped collections of sound waves, or sound fields, are used in a variety of technologies, including medical imaging. The new metamaterial can be used to more efficiently manipulate sound waves and create sound fields for a variety of purposes.
The super-material is made up of tiny bricks marked by a coiled interior structure. Each brick can be designed to bend, shape and focus sound waves in a different way, and the bricks can be arranged in a grid to create different sound fields. The size of the brick and the layered grid can be scaled up and down for different tasks.
A small sound field, for example, could be designed to target a tumor with ultrasound waves. A larger layered grid and larger sound field could be applied in a variety of audio technologies.
“Our metamaterial bricks can be 3D printed and then assembled together to form any sound field you can imagine,” lead researcher Gianluca Memoli, an informatics research fellow at Sussex, said in a news release. “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 detailed their invention in the journal Nature Communications.
“Our research opens the door to new acoustic devices combining diffraction, scattering and refraction, and enables the future development of fully digital spatial sound modulators, which can be controlled in real time with minimal resources,” said Sriram Subramanian, an informatics researcher and head of Sussex’s Interact Lab.