Researchers have developed an acoustic fabric so sensitive to vibrations that it can detect impacts from microscopic high-velocity space particles. A terrestrial application of these fabrics could be for blast detection and in the future, to act as sensitive microphones for directional gunshot detection.
The fabric system contains thermally drawn vibration-sensitive fibers that are capable of converting mechanical vibration energy into electric energy. When micrometeoroids or space debris hit the fabric, the fabric vibrates and the acoustic fiber generates an electrical signal.
The acoustic fiber was aimed at building next-generation fibers and fabrics for soldier uniforms and battle gear that could detect a variety of physiological parameters such as heart rate and respiration as well as external sounds like gunshots and explosions. Traditional telescopes use light to learn about distant objects; this fabric uses space dust analysis to learn about space.
The Laser-induced Particle Impact Test array — which uses lasers to accelerate tiny particles to supersonic or even hypersonic speeds and allows researchers to image and analyze their impact on target materials — was used to demonstrate that the fabric system could accurately measure the impulse of small particles traveling at hundreds of meters per second.
Scientists are now testing the sensitivity of the acoustic fabric for impacts from microparticles with similar kinematics as certain types of high-velocity space dust. Simultaneously, researchers are baselining the fiber sensor’s resiliency to the harsh environment of low Earth orbit on the International Space Station.
For this initial launch, the research team sent a 10 × 10-cm sample of the fabric to the International Space Station where it was installed on an exterior wall, exposed to the rigors of space. The fabric sample will remain on the orbiting laboratory for one year in order to determine how well these materials survive the harsh environment of low Earth orbit.
The white surface of the International Space Station is actually a protective fabric material called Beta cloth, a Teflon-impregnated fiberglass designed to shield spacecraft and spacesuits from the severity of the elements more than 250 miles above the Earth’s surface.
The research team believes the acoustic fabric could lead to large-area fabrics that accurately measure the impulse on spacecraft of micrometeoroids and space debris traveling at kilometers per second. The smart fabrics may also help provide astronauts with a sense of touch through their pressurized suits by providing sensory data from the exterior of the suit and then mapping that data to haptic actuators on the wearer’s skin.
When the samples return to Earth for post-flight analysis, the researchers will measure any erosion from atomic oxygen, discoloration from ultraviolet radiation, and changes to fiber sensor performance after one year of thermal cycling.