Tech Briefs Magazine - August 2021 - 29

the processes used to optimize the fiber
braiding parameters and tensile properties
of the carbon fiber/CNT yarn hybrid
tow material determine the overall im -
provement in tensile strength for resinimpregnated
fiber tows. Bundles of continuous
carbon nanotube yarns are combined
with a similar format of carbon
fiber, yielding an easily scalable process.
Advantages of the material include
reduced cost by eliminating use of
toughening agents, increased ability to
conform to highly complex geometries,
greater environmental stability compared
to aramid fiber reinforcements
such as Kevlar, and possibly decreased
density. Many hybrid reinforcements
exhibit interfacial compatibility issues,
which could lead to premature failure
via crack propagation at the polymer
matrix interface. In contrast, chemical
similarities between the CNT yarn and
carbon fiber constituents impart the
hybrid reinforcement material with
excellent interfacial compatibility.
NASA is actively seeking licensees to commercialize
this technology. Please contact
NASA's Licensing Concierge at AgencyPatent-Licensing@mail.nasa.gov
or call us
at 202-358-7432 to initiate licensing discussions.
Follow this link for more information:
https://technology.nasa.gov/patent/LEWTOPS-154.
Sound
Waves Power Advances in Smart Materials
High-frequency sound waves can be used to build new materials, make smart nanoparticles,
and even deliver drugs to the lungs for painless, needle-free vaccinations.
RMIT University, Melbourne, Australia
hile sound waves have been
part of science and medicine for
decades, the technologies have always
relied on low frequencies. Researchers
now have shown how high-frequency
sound waves could revolutionize the field
of ultrasound-driven chemistry. One of the
effects of these sound waves on materials
and cells is that molecules seem to spontaneously
order themselves after being hit
with the sonic equivalent of a semi-trailer.
W
The process can enable sustainable
production of super-porous nanomaterials
that can be used to store, separate,
release, and protect almost anything. It
also provides precise, cost-effective, and
fast exfoliation of atomically thin quantum
dots and nanosheets.
Medical applications include nebulization
technology that could deliver lifesaving
drugs and vaccines by inhalation
rather than through injections and encapsulating
drugs in special nano-coatings to
protect them from deterioration, control
their release over time, and ensure they
precisely target the right places in the
body like tumors or infections.
The research team generated high-frequency
sound waves on a microchip to
precisely manipulate fluids or materials.
Ultrasound has long been used at low frequencies
of around 10 kHz to 3 MHz to
drive chemical reactions - a field known
as sonochemistry. At these low frequencies,
sonochemical reactions are driven
by the violent implosion of air bubbles.
This process, known as cavitation, results
in huge pressures and ultra-high temperatures
- like a tiny and extremely localized
pressure cooker.
When high-frequency sound waves
were transmitted into various materials
and cells, the researchers saw behavior
that had never been observed with lowfrequency
ultrasound.
Self-ordering molecules seem to orient
themselves in the crystal along the direction
of the sound waves. The sound waveAn
acoustically created MOF, with the microchip that produced the high-frequency sound waves
used in the process.
Tech Briefs, August 2021
Cov
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ToC
lengths involved can be over 100,000
times larger than an individual molecule.
While low-frequency cavitation can
often destroy molecules and cells, they
remain mostly intact under the high-frequency
sound waves. This makes them
gentle enough to use in biomedical
devices to manipulate biomolecules and
cells without affecting their integrity.
One application is an inexpensive,
lightweight, and portable advanced nebulizer
that can precisely deliver large
molecules such as DNA and antibodies,
unlike existing nebulizers. The Respite
nebulizer uses high-frequency sound
waves to excite the surface of the fluid
29
https://technology.nasa.gov/patent/LEW-TOPS-154 http://www.techbriefs.com http://www.abpi.net/ntbpdfclicks/l.php?202108MDNAV
Tech Briefs Magazine - August 2021

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