Packing a Punch

The peacock mantis shrimp delivers one of the strongest and fastest punches in the natural world. It uses its powerful blows to fend off predators and hunt prey. Recently, scientists at Harvard University in Massachusetts decided to model the mechanism behind the shrimp’s punch. They built a tiny robot that mimics the animal’s explosive strike.

A mantis shrimp’s club-like front appendage works like a mousetrap. Small latch-like structures hold the bent limb in place, storing potential energy. When the latch releases, potential energy changes into kinetic energy—the energy of motion—and the club snaps forward. The scientists’ robot works in a similar way. When its latch is released, a spring-loaded arm whips out at 93 kilometers (60 miles) per hour—nearly the same speed as the mantis shrimp’s club.