Scientists have created a garment that can hear the 'beating' of your heart.
One day clothes can hide on the soundtrack of our lives, all around us can catch the sound inside us. A new fiber acts as a microphone - picking up speech, the sound of leaves and the chirping of birds and converts sound signals into electricity. Woven into the fabric, the material can also be handcuffed and faint sounds like the wearer's heartbeat can be heard, the researchers reported in Nature on March 16. Such clothing can provide a comfortable, non-intrusive - even fashionable - service to monitor or help with body functions.
Acoustic fabrics have existed for thousands of years. But it is used to slow down the sound. This information was given to Wei Yan, a material scientist at Nanyang Technological University, Singapore. Yan, who works on fabric at MIT, says that fabric as a microphone is a completely different concept.
Yan was inspired by his fellow human eardrums. Sound waves produce vibrations on the eardrum. Which is converted into electrical signals by the cochlea. These eardrums are made of fiber. This is according to Joel Fink, a serial scientist at MIT. In the inner layers of the eardrum, collagen fibers are transmitted from the center. While others form central rings. Fink says that crisscrossing fibers play a role in hearing and which are similar to fabrics.
In pursuit of what is happening in the eardrum, the sound vibrates the fabric on the nanoscale. In the new fabric, cotton fibers and a slightly harder material called tavaron effectively convert incoming sound into vibration. This is a fiber woven with threads consisting of a mixture of piezoelectric materials, which produces voltage when pressed or twisted (SN: 8/22/17). The buckling and bending of the piezoelectric-containing fiber produces electrical signals that can be sent to a device reading and recording voltage through a small circuit board.
The team reports that fabric microphones are sensitive to a range of noise levels ranging from quiet libraries to heavy traffic, although they are still investigating what signal processing is needed to distinguish target sounds from ambient noise. Integrated into clothing, Yan says, this sound-sensing fabric looks like regular clothing. And it continues to work like a microphone even after washing 10 times.