Fujifilm presented a new electroacoustic film which can be used as a speaker into the next generation flexible devices. It is engineered so that the sound is not distorted when bended. The trick to achieve this was to change the elasticity of the material according to the frequency it vibrates at. (!!!).
This film is normally soft, but it becomes hard in the audio frequency range. That's because it's designed so that, when the ceramic vibrates in the audio range, from 20 Hz to 20 kHz, the vibrational energy is transmitted to the entire film.
The performance of the diaphragm in a speaker is usually expressed in terms of acoustic velocity and internal loss. The higher those are, the better. Currently, the diaphragms used in speakers are often paper cones. In the audio range, compared with a paper cone, our film has the same acoustic velocity and 2-3 times the internal loss. So, the film itself isn't prone to producing sound, which means it delivers very high audio quality.
So, what's next?:
In the future, it might be possible to make a retractable, thin, flexible display, by using this film in combination with an OLED display