How would you feel if you could turn all the walls of your house into one giant speaker;
Researchers at MIT constructed a new type of loudspeaker on thin paper that is light and durable enough to fit all types of surfaces.
It sounds amazing but we should mention that all new technologies do not mean much if they are too complicated and expensive to commercialize. But the MIT researchers' new speaker promises the opposite: the paper speaker can be made in a three-step process that's seemingly simpler than construction of traditional speakers.
The material described in the MIT paper is not new: the speakers use a polyvinylidene fluoride (PVDF) film, which has piezoelectric properties and has been used for speakers since at least the 70s.
PVDF speakers had numerous design challenges that hampered their commercial viability, such as their problematic durability and limited frequency response.
The main innovation of MIT seems to be the reinforcement of the material with its remodeling. A perforated layer of plastic PET is applied to the PVDF sheet, which when subjected to vacuum heat treatment causes the PVDF to compress and pass through the perforations, creating myriad of tiny domes.
So instead of vibrating the entire PVDF sheet, vibration domes are used. Meanwhile, the PET layers surrounding the domes add the necessary structural integrity so that the material can bend and adhere to surfaces without interfering with sound reproduction.
Manufacturers can modify the acoustic properties of the material by changing the size and rearrangement of the canopies. The domes could be adjusted to focus the sound on specific locations in a room, used in ultrasound imaging, or even "provide a new method of stirring chemicals."
The weight and flexibility of the new material also means that it could be used as wallpaper. The ability to cover large areas and adjust the sound means that you could theoretically turn your walls into noise canceling surfaces that prevent outside noise.