Researchers
at the Army's Institute for Soldier Nanotechnologies at the Massachusetts
Institute of Technology develop an acoustic fabric being tested on the
International Space Station could be used to develop space dust telescopes and
allow astronauts to feel through their pressurized suits . Credit: Space BD /
JAXA - image composite by Juliana Cherston, MIT.
An
Army-funded smart fiber being tested on the International Space Station could be
used to develop space dust telescopes and allow astronauts to feel through
their pressurized suits.
Researchers
at the Army's Institute for Soldier Nanotechnologies at the Massachusetts
Institute of Technology developed an acoustic fabric so sensitive to vibrations
that it can detect impacts from microscopic high velocity space particles. A
more earthly application of these fabrics could be for blast detection and in
the future 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.
"This
is an exquisite example of harnessing nanoscience for technology development
that bridges the physical and digital domains," said James Burgess, ISN
program manager for the Army Research Office, an element of the U.S. Army
Combat Capabilities Development Command, now known as DEVCOM, Army Research
Laboratory. "Delivering revolutionary methodologies that result from
foundational science is always one of our main priorities, and the opportunity
to collect data from space dust using a fiber sensor as a key building block of
the system is truly exciting."
The U.S.
Army established the ISN in 2002 as an interdisciplinary research center
devoted to dramatically improving the protection, survivability, and mission
capabilities of the Soldier and Soldier-supporting platforms and systems.
The
acoustic fiber was developed through ISN projects 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," said Dr. Yoel Fink, professor of
Materials Science and Electrical Engineering at MIT. "This is a great
example of how ISN projects allow us to be highly responsive to opportunities
and meet challenges far beyond what we initially imagined."
MIT
graduate student Juliana Cherston, the project's leader, applied another piece
of ISN technology—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—to
demonstrate that the fabric system could accurately measure the impulse of
small particles traveling at hundreds of meters per second.
Scientists
are now using ISN facilities to test the sensitivity of the acoustic fabric for
impacts from micro-particles 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 worked with the Japan Aerospace Exploration
Agency and Japanese company Space BD to send a 10 cm by 10 cm sample of the
high-tech fabric to the International Space Station, where it was installed on
an exterior wall, exposed to the rigors of space. The fabric sample, unpowered
for now, 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 team
is also scheduled for an electrically powered deployment of the fabric through
sponsorship of the International Space Station U.S. National Laboratory in late
2021 or early 2022. The International Space Station U.S. National Laboratory
works in cooperative agreement with NASA to fully utilize the orbiting platform
to bring value to our nation through space-based research and enable a low
Earth orbit economy.
"Thermally
drawn multi-material fibers have been developed by our research group at MIT
for more than 20 years," said Dr. Wei Yan, postdoc in MIT's Research
Laboratory of Electronics and the Department of Materials Science and
Engineering. "What makes these acoustic fibers special is their exquisite
sensitivity to mechanical vibrations. The fabric has been shown in ground
facilities to detect and measure impact regardless of where the space dust
impacted the surface of the fabric."
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.
In one
year, these samples will 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.
"It's
easy to assume that since we're already sending these materials to space, the
technology must be very mature," Cherston said. "In reality, we are
leveraging the space environment to complement our important ground-testing
efforts. Our focus is on baselining their resiliency to the space
environment."