Squid Beak Design
Engineers are fascinated by the composition gradient in a squid's beak. From the Eurekalert:
"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." ...
"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." ...
"'I’d always been skeptical of whether there is any real advantage to "functionally graded" materials, but the squid beak turned me into a believer,' said co-author Frank Zok, professor and associate chair of the Department of Materials at UC Santa Barbara.
"'Here you have a "cutting tool" that’s extremely hard and stiff at its tip and is attached to a material –– the muscular buccal mass –– that has the consistency of Jell-o,' said Zok.
"'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!'"