How one underwater creature’s anatomy could hold the key for stronger body armor
November 2012 - Crawling across the ocean’s floor is a 4-inch-long crustacean that can move faster than a 0.22 caliber bullet. This creature is known as the mantis shrimp. With a fist-like club used to destroy shells and exoskeletons of other underwater creatures, the resilience of this club, which can withstand 50,000 high-velocity strikes during its lifespan—equivalent to 50,000 bullet impacts, has Dr. David Kisailus and fellow researchers at the Bourns College of Engineering, University of California, Riverside, contemplating its real-world applications.
“I learned of the mantis shrimp’s club in discussions with my post-doctoral researcher, Dr. James Weaver, an invertebrate zoologist,” says David Kisailus, assistant professor of chemical/environment engineering at Bourns College of Engineering. Dr. Weaver introduced Kisailus to research by Currey and Patek, “[who] did some nice initial work studying different aspects of the mantis and its club.” According to Patek’s research, the shrimp can deliver impact forces thousands of times its own weight, and Currey concludes that despite the thousands of repeated blows it delivers, the limb is rarely damaged.
But it wasn’t just the intense speed or the 200 pounds of the club’s impacting force that drew this research team to the animal, it also was its more primal characteristics. “These are highly territorial creatures and we dare not leave them in our glass tanks as they have the capability of damaging or potentially smashing through the glass,” says Kisailus.
Contemplating how easily a mantis shrimp can smash through glass, it’s not hard to believe that this sea creature’s unique anatomy could have practical applications on land. “Its club is a multi-regional composite with each region serving a highly-specific function.”
Although their research team is still hard at work exploring the armor’s possibilities they have settled on one particular focal point. “The most practical application would be for soldiers exposed to high-velocity rounds, such as in Afghanistan and Iran,” says Kisailus. “However, our intent is to address armor for both military and police.” With the help of this forceful crustacean, they hope to create body armor that one day could mirror that of the mantis shrimp’s club. Having a suit of armor that withstands the same 50,000 high-velocity strikes that the mantis shrimp experiences, could have a significant impact on how soldiers and police officers are protected during combat situations.
The first obstacle they will have to face when it comes time to create the armor is the weight. “We want and need to reduce the weight,” says Kisailus. “Second is the ability to stop projectiles, including bullets and shrapnel. We also want them to be puncture resistant, for example, against knife attacks.”
Though the main focus currently is on military and law enforcement, Kisailus admits that this truly could have applications in multiple industries, “including the automotive, aerospace and sports industries.” Imagine what a football player could do with a uniform as durable and strong as the mantis shrimp’s club.
With research still in progress, Kisailus could not comment on the specific metals used, but says “they are currently looking into multiple classes of materials, including metals, ceramics and polymers, to help shape this human armor.”
Although the team has already spent years on this endeavor, there is still more research to be conducted before they begin designing the armor. It took five years alone to determine the basic geometry and mechanics of the club, a process that Kisailus calls “long and tedious, yet exciting and rewarding.”
“Essentially my team had to uncover the different aspects of the club,” says Kisailus. “Determining material components within the club, how these components were architectured on the nanoscale, measuring its mechanical properties, using modeling to confirm our observation and finally trying to mimic its structure.”
As of now, the team is working to uncover more details about the club’s architecture and what aspects give rise to its incredible abilities. But one thing that gives the team a leg up is everyone involved is highly interdisciplinary. “Those in my lab have consisted of chemical engineers, material scientists, mechanical engineers, electrical engineers, physicists, chemists, environmental scientists, molecular biologists and invertebrate zoologists,” says Kisailus. “All of these researchers offer a new and unique perspective on a specific topic, making our weekly group meetings both challenging and exciting.”
New perspectives that hopefully with time will create a near impenetrable material that will not only protect soldiers and police officers from the dangers of combat, but also can cushion athletes from the bone-breaking blows of a tackle. MM