Armored Shrimp Inspires New Military Armor

Scientists are hoping that by examining the qualities of the club-like arm of the underwater mantis shrimp, they can develop new, more efficient impact-resistant structures.

The findings could pave the way for a new approach to military armors and even aircraft frames.

The orange fist of the mantis shrimp accelerates underwater at speeds faster than a 22-caliber bullet. Through repeated blows, the mantis shrimp can break the shells of mollusks and crab, both of which have been studied before for their resistances to impact.

David Kisailus and his team at University of California, Riverside's Bourns College of Engineering were curious as to how the mantis shrimp survives up to 50,000 high-velocity strikes on prey during its lifetime. Due to the speed of these strikes, it's almost the same as surviving 50,000 bullet impacts.

"This club is stiff, yet it's light-weight and tough, making it incredibly impact tolerant and interestingly, shock resistant," Kisailus said. "That's the holy grail for materials engineers."

The study determined that the mantis shrimp's club is made up of three distinct regions that help make it tougher than many of today's engineered ceramics.

The impact region is made of a mineral similar to human bone. Inside, there are organized and rotated layers of chitin (a type of complex sugar) fibers that absorb the stress waves from the impact. The club is covered on both sides by carefully oriented chitin fibers which hold the entire thing together during impact.

Kisailus's main goal is to figure out how to implement these findings into a lighter, more durable body armor for military personnel. He would like to cut the existing body armor's weight and thickness by one-third. Currently, body armor can add up to 30 pounds of weight to a service member's load.

Kisailus previous studied other marine animals such as snails, abalone, chiton, and sea urchins.

"We have been studying these other organisms when we should have been studying this guy because he literally eats them for breakfast," Kisailus said.

The impact of the mantis shrimps blow is more than 1,000 times its own body weight, and Kisailus has to actually keep them in a special aquarium with stronger glass.