Tech Briefs Magazine - February 2023 - 29

the designated information to be accessed
by the user.
Daniel Salas demonstrates how the hidden magnetic tag can store a cache of information within an
item. (Image: Texas A&M Engineering)
The team's custom three-axis magnetic
sensor is capable of mapping the
surface and revealing the regions where
an embedded magnetic tag is accessible.
The team is implementing metal
additive manufacturing techniques to
accomplish its goal of successfully embedding
readable magnetic tags into
metal parts without compromising on
performance or longevity. Researchers
used 3D printing to embed these magnetic
tags below the surface into nonmagnetic
steel hardware.
Other applications for this method include
traceability, quality control and
more, largely depending on the industry
in which it is used.
Once embedded into a nonmagnetic
item, the magnetic tag is readable using
a magnetic sensor device - such as a
smartphone - by scanning near the correct
location on the product, allowing
While other methods exist for imprinting
information, they primarily require
sophisticated and costly equipment that
introduces a barrier to real-world implementation.
This is the first time that magnetic
properties of the material are being
used in this way to introduce information
within a nonmagnetic part, specifically
for the 3D printing of metals.
To map the magnetic reading of the
part, the team created a custom
three-axis magnetic sensor capable of
mapping the surface and revealing the
regions where the embedded magnetic
tag was accessible. While the system is
more secure than a physical tag or code
located on the exterior of an item, the
team is still working to improve the
complexity of the method's security.
According to the team, as the project
continues, the next steps include developing
a more secure method of reading the
information, possibly through the implementation
of a physical " dual-authentication "
requiring the user to apply a specific
treatment or stimulus to unlock access to
the magnetic tag.
For more information, contact Amy
Halbert at ahalbert@tamu.edu; 979-4584243.
3D-Printed
Sensors May Lead to Better Weather Research
These digitally manufactured plasma sensors could help scientists combat climate change.
Massachusetts Institute of Technology, Cambridge, MA
A
team of MIT scientists has created
the first completely digitally manufactured
plasma sensors - also known as
retarding potential analyzers (RPAs) -
for orbiting spacecraft. The sensors are
used by satellites to determine the chemical
composition and ion energy distribution
of the atmosphere.
The 3D-printed, laser-cut hardware
performed on par with expensive, stateof-the-art
semiconductor plasma sensors
that were manufactured in a cleanroom.
By contrast, the 3D-printed sensors can
be produced for tens of dollars in a matter
of days.
Their low cost and speedy production
make the sensors ideal for CubeSats, and
they're often used for communication
and environmental monitoring in
Earth's upper atmosphere.
The researchers developed RPAs using a
glass-ceramic material more durable than
Tech Briefs, February 2023
MIT researchers have demonstrated a 3D-printed plasma sensor for orbiting spacecraft that works just
as well as much more expensive semiconductor sensors. (Image: MIT researchers, edited by MIT News)
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Tech Briefs Magazine - February 2023

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