Indistinguishable from regular clothing, all of the necessary components (microphone, lithium battery, etc) are woven into the fabric itself.

Under a contract from the Intelligence Advanced Research Projects Activity (IARPA), an expert team led by SRI research engineers Marcus Bagnell and Nicole Heidel, specialists in fiber technologies and collaborators at North Carolina State University and International Fabric Machines (IFM), a textile maker, will seek to incorporate a piezoelectric material into a fabric that acts like a microphone — a textile that can record audio. The key component will be piezoelectric threads woven into the fabric, which were demonstrated in Nature last year. The team will work to seamlessly integrate the sensor, along with its support electronics into a textile that closely resembles the ones used in off the shelf clothing.

“When sound waves strike the fabric, it stretches the piezoelectric threads, producing an electric signal like the diaphragm of a microphone,” says Bagnell, who is principal investigator. “The fabric is essentially a drum. The sound waves bend the piezoelectric threads, creating an electronic waveform that can be recorded and played back.”

Pulling on the thread

The project is known as “Smart Electrically Powered and Networked Textile Systems” — SMART ePANTS, for short. Eventually, the team hopes to fashion a whole garment — a shirt, pair of pants, socks, underwear even — that records sound. IARPA refers to these garments as primary clothing.