Paper-thin loudspeaker developed at MIT could be used as wallpaper
Researchers at the Massachusetts Institute of Technology (MIT) have developed a paper-thin loudspeaker that can transform objects into an active audio source. The flexible film can be bonded to any surface, producing high-quality sound with minimal distortion.
Demonstrated in a YouTube video, the speaker is about the size of an adult human hand and weighs around the same amount as a dime. The film consists of a thin layer of polyvinylidene fluoride (PVDF), a piezoelectric material covered with tiny domes that are one-sixth of the thickness of human hair. When a voltage is applied to them, these domes move, shifting the air above the film to generate sound.
The speaker requires 100 mW of power per square meter of speaker area to generate around 86 dB of sound at 25 V and a frequency of 10 kHz. According to the research team, this is significantly less than a more traditional loudspeaker, which would need 1 W of power for a similar output.
The MIT researchers suggest that the ultra-thin material could be used as wallpaper in a room or on a car’s interior. Other uses for the film include active noise cancellation in areas like a cockpit by producing equal and opposite sound waves. Another suggested scenario is with smart devices, as the small amount of power required for the film would suit gadgets with limited battery life.