Eggshell nanostructure protects a chick and helps it hatch
Nanoscale changes occur as a chicken egg incubates
JUST HATCHED Scientists have zoomed in on the internal structure of the chicken eggshell to figure out how it can protect developing chicks while eventually letting them break free.
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A chicken eggshell has a tricky job: It must protect a developing chick, but then ultimately let the chick break free. The secret to its success lies in its complex nanostructure — and how that structure changes as the egg incubates.
Chicken eggshells are about 95 percent calcium carbonate by mass. But they also contain hundreds of different kinds of proteins that influence how that calcium carbonate crystalizes. The interaction between the mineral crystals and the proteins yields an eggshell that’s initially crack-resistant, while making nanoscale adjustments over time that ultimately let a chick peck its way out, researchers report online March 30 in Science Advances.
Researchers used a beam of ions to cut thin cross sections in chicken eggshells. They then analyzed the shells with electron microscopy and other high-resolution imaging techniques. The team found that proteins disrupt
