Special shell protects Antarctic scallop from ice build-up

Date:
March 3, 2022
Source:
Max Planck Institute for Polymer Research
Summary:
Airplane wings that don't ice up or solar cells that generate
electricity even in winter - ice-free surfaces are important
for many applications. A team of scientists has now studied an
Antarctic scallop species that opposes the icing process with
the help of its shell surface. Due to their special structure,
thin layers of ice adhere poorly and are easily washed away by
the flow. The discovery could help in the development of ice-free
bionic surfaces in the long term.



FULL STORY ========================================================================== Antarctic waters have conditions in which objects and living creatures
can freeze even under water. This is a major problem for marine travel in
polar regions. So-called supercooled water has a temperature just below
the freezing point. Due to the high salt content, water in Antarctica has
a freezing point of about -1.9 DEGC, but is about 0.05 DEGC colder. The smallest disturbances such as grains of sand or surfaces can cause this supercooled water to freeze - - with sometimes fatal consequences for
creatures that cannot survive frozen.


==========================================================================
The Antarctic scallop Adamussium colbeckiresists this, as chemist Konrad Meister knows. Meister is a professor at the University of Alaska and
heads a research group in Mischa Bonn's department at the Max Planck
Institute for Polymer Research (MPI-P) in Mainz. During an expedition in Antarctica, divers drew his attention to the scallop with the efficient
ice protection mechanism.

"Our divers reported that they had never observed large-scale ice on
the surface of this native scallop species," Meister says.

The international research team, consisting of members of several
MPI- P research groups as well as the University of Oregon, suspects
that the scallop species developed a special surface structure during
evolution that protects it from icing. While scallops in warmer regions
have disordered or smooth shell surfaces, the Antarctic species has a microscopic, very regular structure.

The microscope reveals small ridges that run in a radiating pattern
on their shell. These ridges ensure that water freezes preferentially
there. If the freezing process continues, a continuous layer of ice
forms, resting only on the ridges. Due to the low adhesion between ice
and shell, the smallest underwater flow can therefore wash off the ice
again and the scallop does not freeze.

In addition to microscope studies, the research team also conducted
icing experiments with the Antarctic and with a scallop from warmer
regions. It was found that far less force is needed to remove the ice
layer on the Antarctic scallop than for the other species.

"It is exciting how evolution has obviously given this
scallop an advantage," says Konrad Meister. "New technological
applications based on the principle of bionics are conceivable
from the knowledge of the ice-free shell. For example,
non-icing surfaces could be highly interesting for polar shipping." ========================================================================== Story Source: Materials provided by
Max_Planck_Institute_for_Polymer_Research. Note: Content may be edited
for style and length.


========================================================================== Related Multimedia:
* Surface_structure_on_the_shell ========================================================================== Journal Reference:
1. William S. Y. Wong, Lukas Hauer, Paul A. Cziko, Konrad Meister.

Cryofouling avoidance in the Antarctic scallop Adamussium colbecki.

Communications Biology, 2022; 5 (1) DOI: 10.1038/s42003-022-03023-6 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/03/220303112214.htm

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