The sharp beak of the Humboldt squid is one of the hardest and stiffest organic materials known. Engineers, biologists, and marine scientists at the University of California, Santa Barbara, have joined forces to discover how the soft, gelatinous squid can operate its knife-like beak without tearing itself to pieces.
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The key to the squid beak lies in the gradations of stiffness. The tip is extremely stiff, yet the base is 100 times more compliant, allowing it to blend with surrounding tissue. However, this only works when the base of the beak is wet. After it dries out, the base becomes similarly stiff as the already desiccated beak tip.
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“You can imagine the problems you’d encounter if you attached a knife blade to a block of Jell-o and tried to use that blade for cutting. The blade would cut through the Jell-o at least as much as the targeted object. In the case of the squid beak, nature takes care of the problem by changing the beak composition progressively, rather than abruptly, so that its tip can pierce prey without harming the squid in the process. It’s a truly fascinating design!”
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“If we could reproduce the property gradients that we find in squid beak, it would open new possibilities for joining materials,” explained Zok. “For example, if you graded an adhesive to make its properties match one material on one side and the other material on the other side, you could potentially form a much more robust bond,” he said. “This could really revolutionize the way engineers think about attaching materials together.”