What can we learn from mollusks about creating complex architecture?

Researchers have uncovered for the first time how mollusks build ultradurable structures with a level of symmetry that outstrips everything else in the natural world, with the exception of individual atoms. Research that could inform future high-performance nanomaterials.

“We humans, with all our access to technology, can’t make something with a nanoscale architecture as intricate as a pearl,” says Robert Hovden, an assistant professor of materials science and engineering at the University of Michigan and an author of the paper. “So we can learn a lot by studying how pearls go from disordered nothingness to this remarkably symmetrical structure.”

The analysis was done in collaboration with researchers at the Australian National University, Lawrence Berkeley National Laboratory, Western Norway University, and Cornell University.

Published in the Proceedings of the National Academy of Sciences, the study found that a pearl’s symmetry becomes more and more precise as it builds, answering centuries-old questions about how the disorder at its center becomes a sort of perfection.

Layers of nacre, the iridescent and extremely durable organic-inorganic composite that also makes up the shells of oysters and other mollusks, build on a shard of aragonite that surrounds an organic center. The layers, which make up more than 90% of a pearl’s volume, become progressively thinner and more closely matched as they build outward from the center.

“When we build something like a brick building, we can build in periodicity through careful planning and measuring and templating,” he says. “Mollusks can achieve similar results on the nanoscale by using a different strategy. So we have a lot to learn from them, and that knowledge could help us make stronger, lighter materials in the future.”