Secret of the power of the mantis shrimp fist

  The “hand” of the mantis shrimp is equipped with a powerful boxing weapon. When it swings its fist, it produces a power equivalent to a bullet shot with a 0.22-inch caliber pistol. Now we know how it does this: it’s not that it has particularly developed muscles-it does not have biceps, but that its arms have natural elasticity that allows it to move at a speed of 23 meters per second. Fist-shaped appendages are swung.
  The key to generating such a strong elasticity is a saddle-shaped structure on the appendage. Its working principle is a bit similar to bows and arrows. The muscles pull the saddle-shaped structure to make it bend like a bow. When released, the energy is transferred to the fist of the appendage.
  In daily life, if the bow is too tight, it will break easily. But scientists have discovered that the saddle-shaped structure of the mantis shrimp can hold all the energy without breaking because it has a two-layer structure, with an elastic biopolymer on the top and a ceramic-like material on the bottom.
  When the mantis shrimp shrinks its fist, the top of the saddle-shaped structure is stretched and the ceramic material at the bottom is compressed. Ceramic materials can store a lot of energy (deformation energy) when they are compressed, but if only ceramic materials are used, the entire structure is prone to brittle cracks when bending and stretching (because ceramic materials are more brittle). Biopolymers are elastic and have strong adhesion, which can keep the entire structure intact. Once the taut saddle-shaped structure is released, it will drive the fist below to slam out quickly, producing a daunting impact.
  This structure of the mantis shrimp will be helpful for the development of micro-robots in the future.