Squid Beak: A Truly Fascinating Design
A new class of flexible yet tough materials may be in our future, thanks to a study of squid beaks. Scientists at University of Santa Barbara, reported National Geographic News and Science Daily, were curious how the squid anchors its tough, hard beak in soft tissue. Try anchoring a knife in Jell-o and you get a picture of the problem.
The squid’s secret is a progressive stiffening from the soft tissue where it is anchored to the beak itself. This allows the force from the beak to be gradually attenuated down the structure. “The tip is extremely stiff, yet the base is 100 times more compliant, allowing it to blend with surrounding tissue,” the article states.
If engineers could imitate this graduated stiffness technique, “This could really revolutionize the way engineers think about attaching materials together.” Ali Miserez, the lead author, noted another benefit. “Biological materials are ‘made’ by animals at the temperature of oceans and using naturally occurring chemicals,” he said. “If we can fully understand the chemistry and copy it, then that could lead to a generation of synthetic materials that are less harsh to the environment and made at a lower energetic cost.”
Frank Zok, a materials scientist at UCSB and co-author of the study, was fascinated with the squid solution to an engineering problem. “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,” he said. “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!”
The original paper in Science also used the word “design.”1 The abstract stated: “These findings may serve as a foundation for identifying design principles for attaching mechanically mismatched materials in engineering and biological applications.” Further down, another sentence said, “We found that the squid’s task is facilitated by a beak design that incorporates large gradients in mechanical properties, intricately linked with local macromolecular composition, from the hard, stiff tip to the soft, compliant base.” In a commentary on the paper in the same issue,2 Phillip Messersmith, a biomedical engineer at Northwestern U, compared human engineering to animal design:
Current synthetic biomimetic materials remain primitive in comparison to their natural counterparts. Our ability to incorporate elements of biological inspiration into the design of synthetic materials will be further enhanced through studies such as that by Miserez et al. that advance our understanding of the composition, structure, and processing of complex biological tissues.
1. Miserez, Schneberk, Sun, Zok and Waite, “The Transition from Stiff to Compliant Materials in Squid Beaks,” Science, 28 March 2008: Vol. 319. no. 5871, pp. 1816-1819, DOI: 10.1126/science.1154117.
2. Phillip B. Messersmith, “Materials Science: Multitasking in Tissues and Materials,” Science, 28 March 2008: Vol. 319. no. 5871, pp. 1767-1768, DOI: 10.1126/science.1155122.
Thank you, reporters and scientists, for sparing us any evolution talk in these reports. Fability (01/16/2007 commentary) is not a requirement for understanding – or for science-advancing inspiration.