from Lisa Potter at Real Clear Science:
Skin has to be flexible enough to jump, crawl, and kick with us. It also has to be resilient enough to withstand our falls, scrapes, and cuts. Scientists have marveled at skin's strength for years without knowing why it's so durable.
Now, scientists have identified the mechanical properties that give skin its toughness. Their findings are the first to show that collagen, the most abundant protein in skin, moves to absorb stress and prevent the skin from tearing. In the future, this knowledge could help us use nature's blueprint to make better synthetic skin and improve the strength of man-made materials.
"[Skin's] tear resistance is remarkable," said the study's co-author Robert Ritchie, a professor of engineering at the University of California, Berkeley and Lawrence Berkeley Laboratory. "Quite frankly, what surprised me is that we couldn't break the stuff to begin with."
The secret weapon lies in the dermis, the thickest of the skin's three layers. This middle layer mostly consists of strong tendrils of collagen. The article, published last month in Nature Communications, described how collagen's structure allows it to efficiently distribute pressure and prevent tearing.
"What's happening is the collagen is moving in such a way to absorb energy and carry more load," said Ritchie. This happens in distinct mechanical stages.
The entire article can be read here.