Medical Design Briefs - February 2021 - 22

Spiderwebs Inspire 3D
Photodectors
Researchers used some architectural
features from spiderwebs to develop
3D photodetectors for biomedical
imaging. Spiderwebs typically provide
excellent mechanical adaptability and
damage-tolerance against various mechanical loads such as storms. The
A spiderweb-inspired fractechnology uses the structural architectal design is used for
hemispherical 3D phototure of a spiderweb that exhibits a
detection to replicate the
repeating pattern.
vision system of arthroThis provides unique capabilities to
pods. (Credit: Sena Huh
distribute externally induced stress
image).
throughout the threads according to
the effective ratio of spiral and radial dimensions and provides
greater extensibility to better dissipate force under stretching.
It also can tolerate minor cuts of the threads while maintaining
overall strength and function of the entire web architecture.
The resulting 3D optoelectronic architectures are particularly attractive for photodetection systems that require a large field
of view and wide-angle antireflection, which will be useful for
many biomedical imaging purposes. The assembly technique
enables deploying 2D deformable electronics in 3D architectures, which may foreshadow new opportunities to better
advance the field of 3D electronic and optoelectronic devices.
For more information, visit www.medicaldesignbriefs.com/
roundup/0221/photodetectors.
Improved Polymer Electrode for
Electronic Skin
Scientists have improved electrical
conductivity in a polymer electrode for
e-skin applications. Their approach is
simple and cheap, but further enhancements are needed for the polyThe scientists found their
mer to become a viable alternative to
hydrothermally treated
more expensive gold electrodes.
polymer electrodes funcAmong promising alternative matetioned well in e-skin devices. (Credit: DGIST)
rials for electrodes is the polymer
PEDOT:PSS. It is biocompatible with
human skin, and it is flexible and relatively cheap. It can be
easily manufactured and made into an electrode.
The researchers found a nontoxic method that significantly
improves performance. They developed a hydrothermal treatment, involving humidity and heat, that enhanced the conductivity of PEDOT:PSS films by a factor of 250. Adding humidity
to a thin film of PEDOT:PSS separated the two types of molecules with a screen of water, while adding heat expanded the
PEDOT chains, increasing the material's overall crystallinity.
These structural changes improved the material's conductivity
from 0.495 to 125.367 Siemens per centimeter (S/cm).
For more information, visit www.medicaldesignbriefs.com/
roundup/0221/electrode.
22

Nanobiomaterial from Mites
Shows Promise
A new nanomaterial from the silk
produced by the Tetranychus lintearius mite has the ability to penetrate
human cells without damaging
them and, therefore, has promising
Nanoparticles applied to
biomedical properties.
reconstruction of one cell.
(Credit: University of La Rioja)
The interest of this new material -
which is more resistant than steel,
ultraflexible, nanosized, biodegradable, biocompatible, and has
an excellent ability to penetrate human cells without damaging
them - lies in its natural character and its size (a thousand times
smaller than human hair), which facilitates cell penetration.
These characteristics are ideal for use in pharmacology and
biomedicine since the material is biocompatible with organic
tissues (stimulates cell proliferation without producing toxicity) and, in principle, biodegradable due to its protein structure
(it does not produce residues).
The resistance of the silk produced by Tetranychus lintearius is
twice that of spider silk, a standard material used for this type
of research, and stronger than steel.
For more information, visit www.medicaldesignbriefs.com/
roundup/0221/nanomaterial.
Nanothermometers Improve
Temperature Imaging
NIST researchers are in the early stages
of a massive undertaking to design and
build a fleet of tiny ultra-sensitive thermometers. If they succeed, their system
will be the first to make real-time measA prototype nanopartiurements of temperature on the microcle for thermometry.
scopic scale in an opaque 3D volume -
(Credit: Adam Biacchi/
NIST)
which could include medical implants.
The project is called Thermal Magnetic
Imaging and Control (Thermal MagIC), and the researchers
say it could revolutionize temperature measurements in many
fields, including biology and medicine. Thermal MagIC will
work by using nanometer-sized objects whose magnetic signals
change with temperature. The objects would be incorporated
into the liquids or solids being studied - the melted plastic
that might be used as part of an artificial joint replacement, for
example. A remote sensing system would then pick up these
magnetic signals, meaning the system being studied would be
free from wires or other bulky external objects.
The final product could make temperature measurements that
are 10 times more precise than state-of-the-art techniques, acquired in one-tenth the time in a volume 10,000 times smaller.
This equates to measurements accurate to within 25 millikelvin
(thousandths of a kelvin) in as little as a tenth of a second, in a volume just a hundred microns (millionths of a meter) on a side.
For more information, visit www.medicaldesignbriefs.com/
roundup/0221/temperature.

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Medical Design Briefs, February 2021

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Medical Design Briefs - February 2021

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