Chemical Engineering January 2023 - 8

Wireless device detects coronavirus - no batteries required
A
collaborative research group in Japan has engineered
a self-sustaining device that can detect
the presence of COVID-19
particles or droplets in air. The
device, which requires no batteries, employs
a magnetostrictive clad plate composed
of iron, cobalt and nickel, generating
power via alternative magnetization
caused by vibration. The vibration resonance
frequency of the Fe-Co/Ni plates,
which are coated with the receptor protein
coronaviruses use to enter our cells,
changes when the virus is absorbed, providing
an indication that COVID-19 particles
are in the air.
" We know that resonance frequency
changes when the weight of a magnetostrictive
material changes, but we set out
to answer whether this is also the case
when a virus is absorbed and if this absorption
is detectable, " says Fumio Narita,
co-author of the study - published
in Sensors and Actuators A: Physical -
and professor at Tohoku University's (Sendai, Miyagi,
Japan; www.tohoku.ac.jp) Graduate School of Environmental
Studies.
The researchers modified a 0.2-mm thick Fe-Co/Ni
M
icr oor -
ganisms
populate
nearly any
plate with a rectifier/storage circuit that harvests bending
vibration energy and enables the wireless transmission
of information. The plate transmits
signals with the power obtained from
bending vibration at 115 or 116 Hz. A
change in clad plate weight affected the
resonance frequency and altered the
transmission intervals, meaning it could
detect any substances that adhered
to the clad plate. Next, the group created
the bio-recognition layer, choosing
to focus on human coronavirus 229E
(HCoV-229E) - one of the seven types
of coronavirus that affects humans. They
immersed the clad plate in a CD13 protein
solution and performed sensing experiments.
When the coated clad plate
was subjected to bending vibration,
the resonance frequency decreased
after HCoV-229 was absorbed, verifying
whether the charged power could
transmit virus detection as a signal.
The device could be used on other
Tohoku University
pathogens with modifications to the bio-recognition
layer. " In the future, we hope to further develop our
device and see if it applies to other viruses, such as
MERS, SARS and COVID-19, " says Narita.
A new tool to capture 'microbial dark matter'
Institute for Biological Interfaces
habitat, no matter
how hostile it is. Their
great variety of survival
strategies is of
huge potential in biotechnology.
However,
most of these organisms
are unknown,
because they cannot
be cultivated. To make better use of this " microbial dark
matter " (MDM), a team of researchers from Karlsruhe
Institute of Technology (KIT; Germany; www.kit.edu)
has developed a " sponge " made of porous, formable
silicone. Embedded in a chip, the material sucks up microorganisms
in the surroundings, which can then be
applied for further research.
" It is quite surprising that nobody ever thought of
using medical silicone for the settlement of bacteria, "
says Christof Niemeyer, professor for Chemical Biology
at KIT's Institute for Biological Interfaces-1. The special
polymer - used for breast implants, for example -
does not interact with its environment. It can be modified
easily, is long-lived and inexpensive. " The material
can take up microorganisms from the environment, no
matter how moist or dry it is. For this purpose, the
silicone had to be processed to a porous, sponge-like
structure, " he explains. The porosity was introduced
into the polymer by adding sodium chloride, which was
8
then dissolved, resulting
in the sponge-like
material. Modified
and unmodified silicone
were then combined
to form " chips "
(photo), as described
in a recent issue of
Applied Materials &
Interfaces.
Experiments revealed
that this silicone
sponge captures
a very large range of microorganisms in its pores.
In the dry air of a poultry farm, the team identified
Actinobacteriota species. These microorganisms are
needed for the production of antibiotics. Moreover,
they can be applied to produce substances to treat
certain cancer diseases. " With the sponge, we can
catch new bacteria that might benefit biomedicine, "
Niemeyer believes.
When the silicone sponge was immersed into a pool
to cultivate pikeperch, researchers found many bacteria
belonging to the Candidate Phyla Radiation group - far
more than in conventional, commercially available material.
" These microorganisms account for about 70% of
the microbial dark matter, as they have not been cultivable
so far, " says professor Anne-Kristin Kaster from the
KIT Institute for Biological Interfaces-5. She and her team
analyzed the captured microorganisms using the latest
sequencing technology.
A patent application has been filed for the silicone chip.
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
JANUARY 2023
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Chemical Engineering January 2023

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