Small mantis shrimp hunt their prey, piercing their shells with special breast appendages. They are not very strong, but evolution has provided these creatures with a shock mechanism that develops a speed of up to 23 m / s. The kinetic energy generated by this is comparable to that of a 22-gauge bullet, which is incredibly powerful for such small animals. And recently scientists figured out how they succeed.
The pectoral appendages of mantis crayfish are similar in design to a loaded crossbow with a bolt - the muscles pull the hard striking part to the body, and when released, it strikes the target with force. The problem is that the experimentally recorded impact force would have to destroy the animal's appendages, which never happens. The whole thing turned out to be in the two-layer structure of the striking part of the appendage - and this was a discovery.
Its upper part consists of a hard material similar to chitin or ceramics, the lower one is plastic biopolymers. The strong upper shrinks when preparing the appendage for impact, which it tolerates much better than bends and twists. The elastic bottom, on the other hand, stretches and realizes its strengths. This allows the entire structure to accumulate a colossal amount of energy without deforming the elements. But scientists have found that specific points of application of efforts are also important - a computer model and experiments with the reconstruction of the impact mechanism have shown how difficult it is to replicate this system.
What is the value of this discovery? Imagine an analogue of a powerful spring, in which there are no voids, so it is three times lighter and takes up ten times less space, but it can accumulate the same amount of energy. This is the key to creating mobile systems for the microrobots of the future, which can do without the usual chassis, jump very far and even literally punch their way through obstacles.