Forum for Science, Industry and Business

Sound-shaping super-material invented

The creation pushes the boundaries of metamaterials - a new class of finely-engineered surfaces that perform nature-defying tasks.

Scientists demonstrate a metamaterial layer made out of lots of small bricks that each coil up space. The space coiling bricks act to slow down the sound meaning that incoming sound waves can be transformed into any required sound field. The creation pushes the boundaries of metamaterials - a new class of finely-engineered surfaces that perform nature-defying tasks. (Video)

Credit: Interact Lab, University of Sussex, copyright © 2017

These materials have already shown remarkable results with light manipulation, allowing scientists to create a real-life version of Harry Potter's invisibility cloak, for example.

But a research team from the Universities of Sussex and Bristol have now shown that they also work with sound waves, which could transform medical imaging and personal audio.

Finely shaped sound fields are used in medical imaging and therapy as well as in a wide range of consumer products such as audio spotlights and ultrasonic haptics. The research published today (date) in Nature Communications shows a simple and cheap way of creating these shaped sound waves using acoustic metamaterials.

The collaborative research team assembled a metamaterial layer out of lots of small bricks that each coil up space. The space coiling bricks act to slow down the sound meaning that incoming sound waves can be transformed into any required sound field.

The new metamaterial layers could be used in many applications. Large versions could be used to direct or focus sound to a particular location and form an audio hotspot. Much smaller versions could be used to focus high intensity ultrasound to destroy tumours deep within the body. Here, a metamaterial layer could be tailor-made to fit the body of a patient and tuned to focus the ultrasound waves where they are needed most. In both cases the layer could be fitted to existing loudspeaker technology and be made rapidly and cheaply.

Dr Gianluca Memoli, from the Interact Lab at the University of Sussex who led the study, 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.

Professor Sriram Subramanian, Head of the Interact Lab at the University of Sussex, added: "We want to create acoustic devices that manipulate sound with the same ease and flexibility with which LCDs and projectors do to light. 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."

Bruce Drinkwater, Professor of Ultrasonics at the University of Bristol, explained: "In the future I think there will be many exciting applications of this technology. 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."

James Hakner | EurekAlert!

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...