If you had to pick the toughest animal in the sea, you’d probably go for the great white shark. Or maybe the giant squid. You probably wouldn’t pick the seahorse—a delicate, awkward little creature that clings to the seafloor. But the seahorse is exactly where armor designers are looking for new insights into building robots.
This video, from UCSD’s Jacobs School of Engineering, explains:
Specifically, the engineers are looking at the tail plates on the little sea creature. Seahorses use their tails to hold on to objects like stalks and stems on the ocean floor. The plates that line their tails have to be both flexible enough to grasp and rigid enough to defend themselves from predators. Here’s the UCSD press release:
Most of the seahorse’s predators, including sea turtles, crabs and birds, capture the animals by crushing them. Engineers wanted to see if the plates in the tail act as an armor. Researchers took segments from seahorses’ tails and compressed them from different angles. They found that the tail could be compressed by nearly 50 percent of its original width before permanent damage occurred. That’s because the connective tissue between the tail’s bony plates and the tail muscles bore most of the load from the displacement. Even when the tail was compressed by as much as 60 percent, the seahorse’s spinal column was protected from permanent damage.
The researchers didn’t start with seahorses when they tried to think of armor to study. First, they looked at armadillos, alligators and other fish. But the flexibility of the seahorse tail is what was interesting to them. Here’s how that tail comes together:
Of course, this isn’t the first unlikely animal that robot and armor designers have looked at for insight. Abalone shells are in the running, too. In fact, the same lab is looking at abalone shells to figure out how they get so hard. LiveScience reports:
Abalones create a highly ordered brick-like tiled structure for their shells that is the toughest arrangement of tiles theoretically possible, says Marc A. Meyers of the University of California, San Diego (UCSD). The tiles are comprised of calcium carbonate, or chalk, sandwiches coated top and bottom with a thin protein.
They’re not limiting themselves to sea creatures, either. The lab also wants to see if toucan beaks—extremely strong but also very light—could be useful. The lab explains:
The beak’s interior is a highly organized matrix of stiff cancellous bone fibers that looks as if it was dipped into a soapy solution and dried, generating drum-like membranes that interconnect the fibers. The result is a solid “foam” of air-tight cells that gives the beak additional rigidity.
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