We are facing the fabric of the future. A team of engineers from the Massachusetts Institute of Technology (MIT) and the Rhode Island School of Design (RISD) have created a new fabric fiber engineered from a piezoelectric material that produces an electrical signal when bent, providing a shape for The shirt converts sound vibrations into electrical signals. In this way, when woven into the lining of a shirt, T-shirt or any other item of clothing, the fabric is capable of detecting the subtle characteristics of the wearer’s heartbeat. Thus, the ‘acoustic tissue’ works like a microphone , converting sound first into mechanical vibrations and then into electrical signals, somewhat emulating how our human ears hear.
As in a human eardrum, sound vibrates the nanoscale fabric. The threads are interwoven with a mixture of piezoelectric materials, which produce a voltage when pressed or bent, and are sent through a small circuit board to a device that reads and records the voltage.
“This tissue can seamlessly interact with human skin, allowing users to comfortably, continuously, real-time, and long-term monitor their heart and respiratory condition ,” explains Wei Yan of MIT and leader of the journal’s work. Nature.
This fabric could provide a comfortable, non-intrusive, even fashionable way to monitor bodily functions or help with hearing. And while acoustic fabrics have been around for quite a few years, they are used for sound dampening not as a microphone. It’s “a totally different concept,” says Yan.
All fabrics vibrate in response to audible sounds, although these vibrations are on the nanometer scale, too small to be detected normally. To pick up these imperceptible signals, the scientists created a flexible fiber that bends with traditional fabric like seaweed on the ocean surface.
What sounds can you pick up?
The fabric can capture sounds that vary in decibels, from a quiet library to heavy traffic, and determine the precise direction of sudden sounds such as applause. And if it’s laid out on a T-shirt, as we’ve noted before, the fabric can detect the subtle characteristics of the wearer’s heartbeat.
And it can also produce sound. Potentially, clothing made from this material could not only continuously monitor our heart rate or breathing in real time, but also give us the ability to answer phone calls and communicate through our clothing, and function as a kind of hearing aid. It would be ideal for people with tinnitus problems or hearing loss.
The possible applications are many. The authors also state that it could be applied to the outermost layer of a spacecraft to “listen” for space dust accumulated on it or placed on buildings to detect cracks or compromised areas of the structure.
To test the invention, the team exposed a garment woven from the special fiber to a variety of sound vibrations, such as those in a library or high-traffic area. He successfully converted the vibrations into the appropriate electrical signals.
“This shows that the performance of the fiber on the membrane is comparable to that of a handheld microphone,” said Grace Noel, co-author of the study.
Finally, the researchers reversed the fiber’s function so that it served not as a sound detector but as a loudspeaker. They recorded a series of spoken words and sent the recording to the fiber in the form of applied voltage. The fiber converted the electrical signals into audible vibrations, which a second fiber was able to detect.
Does it weigh a lot?
According to the researchers, logically the material attached to a regular shirt weighs more than a traditional shirt, such as a light jacket , but it is still light to wear.
Referencia: W. Yan et al. Single fibre enables acoustic fabrics via nanometre-scale vibrations. Nature. Published online March 16, 2022. doi: 10.1038/s41586-022-04476-9.