Lobster’s underbelly is as tough as industrial rubber
Flip a lobster on its back, and you’ll see that the underside of its tail is split in segments connected by a translucent membrane that appears rather vulnerable when compared with the armor-like carapace that shields the rest of the crustacean. But engineers at MIT and elsewhere have found that this soft membrane is surprisingly tough, with a microscopic, layered, plywood-like structure that makes it remarkably tolerant to scrapes and cuts. This deceptively tough film protects the lobster’s belly as the animal scuttles across the rocky seafloor. The membrane is also stretchy, to a degree, which enables the lobster to whip its tail back and forth, and makes it difficult for a predator to chew through the tail or pull it apart. This flexibility may come from the fact that the membrane is a natural hydrogel, composed of 90 percent of water. Chitin, a fibrous material found in many shells and exoskeletons, makes...