Acoustic metamaterials could find their ways into headphones and other wearable audio devices following an EPSRC-funded project undertaken at Strathclyde University.
This is the aim of Dr Joseph Jackson, lecturer in electronic and electrical engineering at Strathclyde who has been awarded £422,394 to undertake the two-year project.
Acoustic metamaterials can be used to cloak objects from sound, suppress noise extremely efficiently, and otherwise manipulate sound.
These properties are made possible by the shape and geometry of the metamaterial and advanced manufacturing techniques now make it possible to build complex geometrical objects with 3D-printing at the microscale.
This presents an opportunity to 3D-print small acoustic systems that can be stacked together to create acoustic metamaterials that work at audio frequencies.
“Unfortunately, acoustic metamaterials, which promise a step change in the way materials interact with sound, are still very large for audio frequencies,” said Dr Jackson. “We will try and miniaturise acoustic materials to make sound absorbing materials that are small and lightweight while retaining good acoustic function.”
To this end, Dr Jackson said the project will use a variety of commercial and custom-made UV-curable polymer resins and use micro-stereolithography to fabricate the metamaterials.
He added that by 2024 the project will have made acoustic metamaterials that interact with sound at audio frequencies.
“Companies are working on noise cancellation technologies, but these are predominantly electroacoustic techniques: acquire signal, phase shift, play it back,” said Dr Jackson. “We are attempting to miniaturise acoustic metamaterials to enable their use in wearable devices instead of or complementary to active noise cancellation.”