Engineers have created a paper-thin speaker

Engineers from the Massachusetts Institute of Technology developed ultra-thin audio speakers with which any surface can be turned into a sound source.

These film speakers reproduce sound with minimal distortion while consuming only a fraction of the power required to run a traditional speaker. The team showed off a palm-sized speaker that weighs like a coin and can produce high-quality sound no matter what surface it's glued to.

Traditional speakers, used in headphones and speakers, use an electrical current that passes through through a coil of wire that creates a magnetic field, moving the speaker membrane and the air above it, which creates sound. Engineers have simplified the design of the speaker by using a thin film of piezoelectric material that moves when voltage is applied, which also moves the air above it and generates sound.

But this also means that such a film cannot be glued to another surface: this will deprive the film of the ability to vibrate - and therefore reproduce sound. To solve this problem, the design was rethought. Instead of making the entire material vibrate, the sound is emitted by many independent micro-domes (each only 15 km high). They are protected from above and below by lining layers, which also increase the strength of the structure during prolonged use.

It is noted that the manufacturing technology is simple and consists of only three stages. It can be used to produce ultra-thin speakers, large enough to cover a car interior or a room with them - just like ordinary wallpaper.

Film speakers can also provide active noise cancellation in noisy environments, such as in an airplane cockpit, by producing sound of the same amplitude but in opposite phase. Noise canceling headphones work on the same principle.

The development can also be used for immersive entertainment to create a surround sound effect in a theater or children's attraction. Given that the film is lightweight and requires a minimum amount of energy to operate, it is ideal for connecting to battery-powered mobile equipment.

The team believes that this technology can be further developed and used in sound sources and microphones.