At the beginning of this year, a revolutionary invention was presented at CES-2018 by scientists from universities in Sussex and Bristol, which, to my surprise, went almost unnoticed. The project to create a fundamentally new sound transducer is called Metasonics and is a real technological breakthrough in sound wave control.
Judging by the data of experimental studies of the British, their technology will become a real revolution for both specialized acoustic equipment and household sound reproducing systems. This is a new type of so-called. an acoustic lens created on the basis of metamaterials, which is capable of focusing sound like a lens in optics and flexibly changing the intensity in a sound field.
Unusual, from the point of view of classical ideas, the possibilities of metamaterials allowed the inventors to create 16 different types of so-called. metakirpichy, on the basis of which was developed a unique transducer of sound waves.
The device allows you to freely manipulate the acoustic field. In fact, this means the creation of local sound reproduction zones in a single space (for example, in a car or a showroom) with narrowly targeted sound radiation.
Metamaterials and application in experimental acoustics
If we talk about metamaterials in general, they are defined in the Wiki as:
“Metamaterial is a composite material, the properties of which are caused not so much by the properties of its constituent elements as by an artificially created periodic structure”
In other words, the main properties of interest to us are formed due to the special structuring of environments, and such properties cannot be found in the natural environment. In turn, acoustic metamaterials change the properties of sound due to a special structure.
If it is very rough and not quite accurate, then metamaterials are obtained by incorporating huge atoms into the structure of the original natural material. In the development process, the creator of the metamaterial has the ability to change the parameters of the structures being implemented. So the form, the size or the period can change.
One of the most demonstrative examples of the properties of such materials is a metamaterial with a “left-sided” refractive index. The video below shows a schematic representation of how light passes through such material and what happens to it.
Similar and more complex effects using metamaterials can be achieved not only with light, but also with sound waves. Thus, the idea to use metamaterials as special acoustic reflectors, lenses and original “lenses” appeared.
Experiments have shown that the use of acoustic metamaterials makes it possible to control acoustic radiation more efficiently than using other known methods.
Metasonics - the successful start of a future revolution
Despite the fact that acoustic metamaterials have been studied for a relatively long time (since the beginning of zero), tangible success was achieved only last year. A working prototype of an acoustic lens from metamaterials, capable of creating and modifying a narrowly focused acoustic field in real time, appeared thanks to scientists from the universities of Sussex and Bristol.
It should be noted that such devices that provide focusing of acoustic waves existed before, but did not use metamaterials and were therefore static and cumbersome. Some time ago I came across information about the development of the so-called. “Sound spots”, however, due to the complexity of manufacturing and low manufacturability, it was not widespread.
A group of British researchers led by a computer science professor at the University of Sussex, Sriram Subramanian, developed a mobile version of a spatial sound modulator, which was named Metasonics.
The design of the converter is based on using not one type of metamaterial, but 16 different structures, which are made in the form of bricks. They were called acoustic metamaterial brick.
At the beginning of the video below, the principle of operation of the transducer and the acoustic fields that it creates, as well as the types of “bricks” that are used to create a modulator, are demonstrated.
Acoustic levitation well demonstrates the intensity of sound waves in a localized area of space that the new transducer allows. At the same time, it is much more compact compared to the previously existing stationary analogues.
The developers of Metasonics in November last year already received a starting investment of 10,000 pounds at a competition at the University of Bristol. It is very likely that in the near future the company will receive more impressive investments. They are often compared to another British university startup, Ultrahaptics, which started in 2013 with $ 20,000 and drew 23 million by May 2017.
Application options
According to the inventors, the lens can be used almost anywhere where there is a need for separation and direction of sound streams. So the most promising developers consider using Metasonics in a car, where the driver will receive information from the navigator, the front seat passenger will listen to the radio, and the rear seats will be comfortably viewed watching a movie without walls and sound insulation.
Similarly, using the transducer, you can voice the local zone in the museum or at the exhibition (without wearable uncomfortable audio guides). Also promising are the modulator's possibilities for advertising, when several people at a short distance from each other can broadcast various audio streams or broadcast an advertising message with tracking of a focused sound beam behind the object.
Another opportunity offered by the project developers is the use of acoustic lenses in fitness bracelets, which will help in communication with the gadget owner and provide feedback during running and active exercises.
No less promising is the use of the product for audio zoning premises. In fact, this project can kill the market of home headphones or at least press out their unshakable positions as an individual means of sound reproduction.
The creators of the “brick” meta-miracle themselves are sincerely convinced that the Metasonics technology will one day become as common as an LCD screen.
Current stage
At the moment, a team of 2 universities is busy resolving the issue of dynamic restructuring of layers of material. As soon as scientists accomplish this task, several more applications will appear. Among others - compact diagnostic ultrasound scanners, as well as the possibility of acoustic damage detection and acoustic therapeutic devices.
In fact, scientists, developers have come close to the creation of fundamentally new acoustic devices that allow for the control of such phenomena as scattering, diffraction and sound refraction with minimal cost. According to the experimenters, it will be completely digital sound modulators controlled in real time.
Total
When I learned about the modulator, I was surprised at how much the device and the material on the basis of which it will be made are able to change the current understanding of acoustic devices, sound radiation. For me, it is obvious that the described technology in a couple of years will begin to gain popularity. I would appreciate your opinion on the possibilities of applying this innovation in the comments. I hope for a lively and correct discussion.