Tech Briefs Magazine - August 2021 - 28

Materials & Coatings
to various types of shoes, including
sneakers and winter boots, and measured
the friction produced when subjects
walked across a force plate - an
instrument that measures the forces
exerted on the ground - covered with a
1 " -thick layer of ice.
They found that with the kirigami
coatings attached, the amount of friction
generated was 20 to 35 percent
higher than the friction generated by
the shoes alone.
They are now working on determining
the best way to attach and incorporate
the kirigami surfaces. They are
considering embedding them into the
soles or designing them as a separate
element that could be attached when
needed.
For more information, contact Abby
Aba zorius at abbya@mit.edu; 617-253-2709.
High-Pressure Soft Lithography for Microtopographical
Patterning of Molded Polymers and Composites
Applications include anti-fouling and anti-contamination, aerodynamic and hydrodynamic
drag reduction, and adhesive joining of composite parts.
Langley Research Center, Hampton, Virginia
ASA Langley developed a method to
apply soft lithography to mold mi -
croscale structures into the surface of
polymer and composite parts. This technology
provides an efficient means to
fabricate microtopographical surface
patterns or features. A polydimethylsiloxane
(PDMS), or similar elastomer, would
incorporate a master pattern, which acts
as a mold through which liquid resin
material flows and hardens to create a
N
rigid, inverse replica of the mold specific
to its intended surface applications.
One application of the technology is
to create super-hydrophobic surfaces
that protect against contamination and
fouling. Another application is to im -
prove adhesion between two parts in
adhesively bonded joints, which is of particular
interest for composite parts where
sanding could expose reinforcing fibers
to degenerative environmental effects.
Another use of the technology is to create
surfaces that reduce drag in aerodynamic
and hydrodynamic applications.
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/LARTOPS-173.
Carbon
Fiber/Carbon Nanotube Yarn Hybrid Reinforcement
Applications include aerospace and automotive components, prosthetics, sporting goods,
and other uses where strength-to-weight ratio is important.
John H. Glenn Research Center, Cleveland, Ohio
istorically, polymer matrix composites
(PMCs) have provided insufficient
toughness for some aerospace
structures. Rubber toughening agents
and thermoplastics are often employed
H
to increase material toughness but such
additives increase viscosity of polymer
resins and increase processing difficulty
and cost. Other reinforcements like
aramids exist but also have inherent
(Left) A tube of NASA's carbon fiber/carbon nanotube yarn hybrid braided reinforcement; (Right)
NASA's braider used to manufacture the reinforcement.
28
Cov
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ToC
issues (e.g., Kevlar absorbs moisture,
which adds weight and is susceptible to
degradation upon UV exposure).
Innovators at NASA Glenn developed
a toughened hybrid reinforcement ma -
terial made from carbon fiber and carbon
nanotube (CNT) yarn for use in
PMCs. The new material improves
toughness and damping properties of
PMCs, enhancing impact resistance, fa -
tigue life, and structural longevity.
The new carbon fiber/CNT yarn hy -
brid material displays excellent toughness
and strength for reinforcing PMC
materials while also mitigating issues associated
with current hybrid reinforcements
like rubber, thermoplastics, and
aramids. The material is a toughened triaxial
braid made from ductile CNT yarn
hybridized with carbon fiber, which is ultimately
used as reinforcement material to
make toughened PMCs. The CNT yarn
component of the reinforcement is solely
responsible for adding toughness, while
Tech Briefs, August 2021

https://technology.nasa.gov/patent/LAR-TOPS-173 http://www.techbriefs.com http://www.abpi.net/ntbpdfclicks/l.php?202108MDNAV

Tech Briefs Magazine - August 2021

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