MIT engineers have created the world’s thinnest speaker

The fact that technical devices are becoming smaller and lighter is not an entirely new development. In principle, this also applies to loudspeakers. Now, however, the engineers at MIT could have made another giant leap in development. Because they have developed a new type of loudspeaker that is as thin as a sheet of paper, weighs less than a dime and also consumes less energy than the products used until now. In terms of sound quality, however, there should be no limitations. This is possible because the researchers have not only further developed the existing technology, but have opted for an entirely new approach. To understand this, let’s first see how a classic speaker works. Here it is electric currents that are passed through a coil of wire, creating a magnetic field. This causes the loudspeaker membrane to vibrate. The air that moves through it then eventually creates the sound we hear.

Image: Felice Frankel via MIT News

The ultra-thin speaker can be glued to the wall

The newly developed loudspeaker, on the other hand, relies on a film made of a specially formed piezoelectric material. If you now put a voltage on it, the desired effect is immediately created: the air is set in motion and sound is produced. So far, however, no unusual design has been used, the speaker cannot simply be placed there. Instead, the demonstration video only shows some sort of slide connected to two cables. But it is possible to stick it on a wall or the like. So far this has been more fundamental research. If the corresponding boxes are actually sold to end customers at a later date, they should look very different again. In any case, only 100 milliwatts of power are needed per square meter of speaker surface. In comparison, today’s speakers with comparable volume and sound quality sometimes require more than one watt of power. Significant progress has also been made on this point.

The sound can also be broadcast in a targeted manner

The researchers involved are also thinking one step further. For example, the loudspeakers could be equipped with ultrasound. They would then be able to recognize where a person is in the room and target them with sound. This would reduce the overall sound level without the target person hearing less. Such approaches have been worked on for several years – for example with the Soundlazer Snap. However, so far no corresponding product has been able to establish itself on the market. A transparent speaker made of iongel has also been developed at Harvard University, which can be built into windows to suppress noise. Here too, however, a wide distribution is still lacking. The basic technology now developed by the MIT researchers, in which targeted mechanical air movements are easily generated, can also be used outside loudspeakers.