Imagine an extremely sophisticated armor, both sturdy and flexible, which is mainly composed of water, but remains strong enough to prevent mechanical penetration.
Now imagine that this armor is not only solid, but also soft and extensible, so that the wearer can easily move parts of his body, swim in the water, cross the ground or hurries to escape danger.
This description might look like a costume worn by a fiction hero from the DC Comics franchise, but it actually describes parts of a lobster's exoskeleton.
Researchers at the Massachusetts Institute of Technology and Harvard believe that the flexible membrane covering the joints and the abdomen of the animal, material as resistant as the industrial rubber used for the manufacture of car tires and hoses. Watering, could guide the development of a new type of product. Flexible bulletproof vest for the human, designed to cover the joints like knees and elbows.
The conclusions of the researchers appeared in a recent edition of the newspaper Acta Materialia.
"We believe this work could motivate the design of flexible armor," said Ming Guo, an assistant professor of career development at the MIT's mechanical engineering department of Arbeloff, at MIT News. that the lobster membrane had helped him survive more than 100 times on Earth. millions of years. "If you could make armor with this type of material, you could move your joints freely, which would make you feel more comfortable."
Bulletproof vests – commonly known as "bullet-proof vests" – are widely used by law enforcement officers and have been known to have saved thousands of handguns and ammunition rifle, according to the National Institute of Justice. But the vests also present challenges. As the Washington Post's Devlin Barrett reported in 2017, Kevlar – a tightly woven fiber board designed to prevent handgun bullets – has an expiry date and generally lasts no more than five years. According to NIJ, bullet-proof vests can also be ill-fitting, especially for female officers who sometimes need a custom fit.
Some studies have shown that bullet-proof vests can also affect the wearer's accuracy and concentration, as well as increase "the physiological cost of performing a task in use", providing both protection and increased risk, according to the National Center for Biotechnology Information.
MIT researchers believe that lobster could offer a solution to the problem of modern bulletproof vests: the more armor is mobile, the less it protects the body of the wearer.
Guo told MIT News that the idea of developing a lobster-inspired body armor had appeared while he was eating one and had noticed that the transparent membrane of the animal's belly was difficult to chew. Unlike the crustacean-like outer shell of bone, the animal's softer tissues remain a mystery, he said.
Once the researchers began dissecting these tissues, they made a surprising discovery. Large cuts in the membrane did not affect the elasticity of the material. The researchers determined that elasticity and strength are due to the unique structure of the membrane, which includes tens of thousands of layers compared to plywood. The fibers in these layers help the material dissipate energy when it is stressed, making it "damage tolerant," the researchers write.
"The knowledge gained from the lobster's soft membrane sheds light on the design of synthetic, soft and durable materials for reliable use in extreme mechanical conditions, including flexible armor that can provide complete body protection without sacrifice limb mobility, "according to the study. added.
Guo told MIT News that materials designed to replicate the strength and flexibility of lobster membranes could also be used in soft robotics and tissue engineering.