Our skin is remarkably resistant to tearing, and now researchers have figured out why. They used X-ray beams and electron microscopes to look at the micro-scale mechanisms at play when rabbit skin is cut and then stretched. A notch in skin does not lead to a full split, as it does in bone, because the initial tear induces structural changes in the collagen fibrils found in the top layer of skin to dissipate the stress at the tip of the cut. Usually collagen fibrils are curvy and arranged in a ramshackle way (pictured), much like a bowl of spaghetti. But in response to a tear they rearrange themselves into alignment with the direction in which the skin is being stretched. They straighten, slide, and stretch to take the strain. Such insights could help researchers to develop better artificial skin for burns victims and more robust flexible electronics for biomedical use.
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
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