Researchers at the KTH Royal Institute of Technology in Sweden have completely redesigned the speaker. The team has found a way to eliminate the use of permanent magnets in stereo speakers by using metallic nanoparticles in the speaker's membrane.
“This is, to our knowledge, the first reported magnetic speaker membrane,” said KTH researcher Richard Olsson.
The new method works by adding cellulose nanofibers that have ferrite nanoparticles distributed evenly throughout the membrane. This means the speaker doesn't need a permanent magnet, and researchers say the sound quality is just as good, if not better, than traditional speakers.
Other speakers use a voice coil that is wrapped around the permanent magnet, which drives the movements of the speaker cone, producing the sound. In the new design, a voice coil is still being used, but it is not wrapped around a magnet or even directly attached to the cone -- it simply produces sound from air movement.
Researchers add that this application can be used in the design of other technologies, such as different modes of transportation.
“We want to look at applications for the material that are driven by magnetic fields. It may, for example, be a form of active damping for cars and trains,” Olsson said in the press release.