Fabric woven in special materials can even hear hand claps and faint sounds such as the user's heartbeat, according to the report the researchers published in Nature on March 16. It is thought that such fabrics could provide a convenient way to monitor bodily functions or aid hearing.
Acoustic fabrics have been around for perhaps hundreds of years, but are used to dampen sound, said Wei Yan, a materials scientist at Nanyang Technological University in Singapore. Yan, who worked on fabric while at MIT, said that using fabric as a microphone is a completely different concept.
Yan and colleagues developed this fabric inspired by the human eardrum. The researchers created a model, as sound waves cause vibrations in the eardrum that are converted into electrical signals by the snail, and the collagen fibers in the inner layers of the eardrum form concentric rings as they radiate from the centre. Accordingly, Yoel Fink, a materials scientist at MIT, stated that cross fibers play a role in hearing and resemble the fabrics that humans weave.
Similar to an eardrum, sound vibrates this special fabric at the nanoscale. This fabric consists of cotton fibers and threads, a somewhat stiff material called Twaron, which efficiently converts incoming sound into vibrations. It is formed by weaving together fibers containing a mixture of piezoelectric materials that produce voltage when pressed or twisted together. Twisting and bending of the fiber containing piezoelectricity creates electrical signals that can be sent via a small circuit board to a device that reads and records voltage.
This fabric microphone is sensitive to a range of noise levels, from a quiet library to heavy traffic, the researchers said. However, they stated that they continue to work on the classification or separation of the received sounds.
Reference:
https://www.sciencenews.org/article/fabric-hear-heartbeat-fiber-vibration-voltage-sound-material
