Tech Briefs Magazine - August 2024 - 23

Self-Cleaning Coatings for Space or Earth
Transparent electrodynamic dust shields usable for solar cells.
Kennedy Space Center, Merritt Island, FL
R
educing dust accumulation on any surface
is key for lunar missions as dust can
damage or impair the performance of everything
from deployable systems to solar
cells on the Moon's surface. Electrodynamic
dust shields (EDSs) are a key method to
actively clean surfaces by running high voltages
(but low currents) through electrodes
on the surface. The forces generated by the
voltage efficiently remove built up, electrically
charged dust particles. Innovators at
the NASA Kennedy Space Center have developed
a new transparent EDS for removing
dust from space and lunar solar cells
among other transparent surfaces.
The new coatings operate at half the
voltage of existing EDSs while being 90 percent
thinner. These capabilities are enabled
by an innovative combination of electrode
patterning and a thin silica protective
layer. The reduced thickness and lower
voltage operation expands possibilities for
integrating EDSs onto transparent surfaces
across industries.
The new transparent EDS technology
is lighter, easier to manufacture, and operates
at a lower voltage than current
transparent EDS technologies. The coating
combines an optimized electrode
pattern with a vapor deposited protective
coating of SiO2 on top of the electrodes,
which replaces either polymer
layers or manually adhered cover glass
(see figure on the right). It has been
shown to achieve similar performances
A
B
Examples of the EDS actively removing the dust from glass surfaces under vacuum when dust is
placed by (A) a brush and (B) by a vacuum dust deposition system. (Image: NASA)
(i.e., over 90 percent dust clearing efficiency)
to previous technologies while
being operated at half the voltage.
The key improvement of the new EDS
coating comes from an innovative method
to successfully deposit a protective layer
of SiO2 that is much thinner than typical
cover glass. Using vapor deposition
enables the new EDS to scale more successfully
than other technologies that
may require more manual manufacturing
methods. The EDS here has been proven
to reduce dust buildup well under vacuum
and may be adapted for terrestrial
uses where cleaning is done manually.
The coatings could provide a significant
improvement for dust removal of solar cells
in regions (e.g., deserts) where dust buildup
is inevitable, but water access is limited.
The EDS may also be applicable for any
transparent surface that must remain transparent
in a harsh or dirty environment.
NASA is actively seeking licensees to
commercialize this technology. Please
contact NASA's Licensing Concierge at
Agency-Patent-Licensing@mail.nasa.gov
or call at 202-358-7432 to initiate licensing
discussions. For more information,
visit https://technology.nasa.gov/
patent/KSC-TOPS-99.
VaCNT Makes Up a Promising Membrane Material
Vertically aligned carbon nanotubes (VaCNT) may benefit ultra- and nanofiltration
processes controlled by nanopores.
Karlsruhe Institute of Technology, Karlsruhe, Germany
M
embranes of vertically aligned carbon
nanotubes (VaCNT) can be
used to clean or desalinate water at high
flow rate and low pressure. Recently, researchers
of Karlsruhe Institute of Technology
(KIT) and partners carried out
steroid hormone adsorption experiments
to study the interplay of forces in
the small pores. They found that VaCNT
of specific pore geometry and pore surface
structure are suited for use as highly
selective membranes. The research was
published in Nature Communications.
Tech Briefs, August 2024
Clean drinking water is of vital importance
to all people worldwide. Membranes
are used to efficiently remove
micropollutants, such as
steroid hormones
that are harmful to health and
the environment. A very promising
membrane material is made of vertically
aligned carbon nanotubes (VaCNT).
" This material is amazing - with
small pores of 1.7 to 3.3 nanometers in
diameter, a nearly perfect cylindrical
shape, and small torsion, " said Professor
Andrea Iris Schäfer. " The nanotubes
www.techbriefs.com
should have a highly adsorbing effect
but have a very low friction only. "
Currently, pores are too large for effective
retention, but smaller pores are
not yet feasible technically.
In experiments with steroid micropollutants,
IAMT researchers studied why
VaCNT membranes are perfect water
filters. They used membranes produced
by the Lawrence Livermore National
Laboratory (LLNL). The finding: The
low adsorption of VaCNT, i.e. deposition
on the surface, is desirable for
23

https://technology.nasa.gov/patent/KSC-TOPS-99 https://www.techbriefs.com

Tech Briefs Magazine - August 2024

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