Person holding two lobsters with their underbellies facing up.

The tough, flexible tissue covering a lobster’s underbelly serves as a model for a new synthetic substance. Credit: D. Lada/Alamy


Material mimicking lobster belly cracks the code for toughness

Who needs a shell? Crustacean’s lower surface spawns a synthetic substance that could lead to flexible armour.

A lobster’s underbelly is protected by a membrane that is strong but flexible, allowing the animal to manoeuvre. Now, that membrane has inspired a strong, flexible synthetic material ― work that could help pave the way for protective fabrics.

Xuanhe Zhao at the Massachusetts Institute of Technology in Cambridge and his colleagues constructed their material as the lobster does: from a hydrogel, a network of water-loving polymer chains. To better mimic the biological version, the researchers welded their polymer threads together with water and partially crystallized them with heat, creating small, scattered crystals inside the fibres, to add structural complexity.

Tearing apart the resulting film requires more than ten times the energy needed to rip up an uncrystallized control sample. Further improvement came when the team stacked layers of polymer in the same manner as the sheets of chitin fibres in the lobster’s soft armour: with each layer at an angle to the one underneath it, like a twisted stack of playing cards.

The researchers shot microscopic steel particles at the material to test its impact resistance, and say it shows promise for making flexible body armour.