In the search for the next groundbreaking tough material, scientists like David Kisalus from the University of California, Riverside are looking to nature for inspiration, including under the sea where one little crustacean packs a walloping punch - the peacock mantis shrimp. "Science Behind the News” is produced in partnership with the National Science Foundation.
Science Behind the News - Bio-Inspired Materials
ANNE THOMPSON, reporting:
On the road, in the air and especially on the battlefield, engineers need materials that are lightweight, strong, and durable. In the search for the next groundbreaking tough material, scientists are looking to nature for inspiration, including under the sea where one little crustacean packs a walloping punch - the peacock mantis shrimp.
DAVID KISAILUS (UC, Riverside): Fisherman call them thumb splitters for a reason, because they can actually break your finger if you put your hand in there.
THOMPSON: David Kisailus, an NSF-funded assistant professor of chemical and environmental engineering at the University of California-Riverside, first heard about the peacock mantis shrimp from one of his students. What fascinated Kisailus is the creature's dactyl club, a tiny appendage that it uses to smash through the shells of its prey with the force of a .22-caliber bullet.
KISAILUS: Oh! Did you get that? She cracked it. This crustacean, it's a crustacean not a shrimp, can actually smash with 200 pounds of force and it's only four inches long. And, you know, as a material scientist and chemical engineer, of course I’m curious to know what is this fist made of?
THOMPSON: The club can sustain up to 50,000 blows before it molts and generates a new one. To understand the club's ability to deliver a powerful blow, yet tolerate the force of repeated impacts without cracking, Kisailus and his team examined a cross-section of the club using a scanning electron microscope to find out what it was composed of and how it was arranged. What they discovered was a unique type of composite material with a distinct structure.
KISAILUS: Having something that's hard and though is actually very difficult to achieve in an engineering sense, and yet biology can do this based on architecting these multi-sectional composites.
THOMPOSN: The club is made up of three regions. The outermost region is called the impact region which is composed of calcium-phosphate, a mineral also found in human bone, with crystals arranged perpendicular to the surface it strikes.
KISAILUS: When the club impacts its prey, the stress from that impact is distributed evenly across the club and it doesn’t fracture.
THOMPSON: Behind the impact region is the periodic region, which has a spiral-like structure made up of different fibers called a helicoid.
KISAILUS: A helicoid, all that is are fibers that are in one layer and then there is another layer of fibers that’s stacked on top of that at a certain angle, and another layer on top that's also off set by another angle and continues to basically be stacked on top of each other until they go around.
THOMPSON: The arrangement of these fibers offers immense energy absorption as the club strikes its prey. The third region, called the striated region, is composed of fibers that wrap around the entire club to keep it compressed, similar to how a boxer wraps his fists with tape.
KISAILUS: The mantis shrimp has managed to evolve in a way to wrap these fibers around its own fists, so it itself won't fail.
THOMPSON: Kisailus is studying the multi-sectional structure of the club in the hopes of producing a new material that could one day be used for stronger, lighter body armor for soldiers. His lab, which has tanks full of remarkable sea life, is an example of a field of study called biomimetics, which looks at biological structures such as this California red abalone shell as a model for constructing improved man-made materials.
KISAILUS: Our goal is to understand biology, specifically bio-materials, how they're made, how they're architected, and use the strategies done by biology or achieved by biology to make new engineering materials.
THOMPSON: By looking to nature and the impressive wallop of this tiny crustacean, Kasailus hopes to have a big impact on soldiers answering the call of duty.
The silk of the humble spider has some pretty impressive properties. It’s one of the sturdiest materials found in nature, stronger than steel and tougher than Kevlar. It can be stretched several times its length before it breaks. For these reasons, replicating spider silk in the lab has been a bit of an obsession among materials scientists for decades.
Science Behind the News, Biomimetics, Bioinspired, Materials, Body Armor, Crustacean, Peacock Mantis Shrimp, Nature, Inspiration, Composite, Engineering, Engineer, Military, Soldiers, Strong, Tough, Club, Fist, Molt, Molting, Prey, Structure, Architecture, Calcuim-Phosphate, Mineral, Crystal, Bone, Impact, Helicoid, Layers, Fibers, Biology, California Red Abalone, Professor, David Kisailus, University of California, Riverside