Shark skeletons are not bones. They are plans.

Sharks have no bones. Instead, their skeletons are made of mineral cartilage, an adaptation that has helped these predators move through the oceans for over 400 million years. A new study It gets a deeper look – literally – on how this cartilage works. Using a combination of 3D 3D high -resolution and mechanical testing, a global team of scientists has mapped the internal structure of cartilage shark and found it much more complicated than it appears on the surface. The findings not only help to explain how sharks maintain their strength and flexibility, but also open the door to the development of hard, adaptable materials based on the mechanics of nature.

The survey focused on the Blacktip sharks (Carcharhinus limbatus) and participated in cooperation between Charles E. Schmidt College of Sciencethe College of Engineering and Computer Science to University of Florida AtlanticThe German electronic Synchrotron (Desy) in Germany and NOAA fishing. Blacktips are medium -sized coastal sharks that are usually found in warm, shallow waters around the world, including the Gulf of Mexico, the Caribbean and parts of Indians and Pacific Oceans. They usually grow about 5 feet (1.5 meters) in length, although some people can reach up to 8 feet (2.4 meters). It was named for the distinctive black marks on the edges of dorsal, pelvic and fins, blacktip sharks mainly eat small fish, squid and crustaceans, using rapid speed bursts to hunt the prey.

The team magnified in their cartilage using X -ray nanomy, a powerful imaging technique that can reveal details to the nanometer scale. What they found was that the cartilage was not uniform. In fact, it had two separate areas, each with its own structure and purpose. One is called “Corpus Calcareum”, the outer mineralized layer, and the other is “intermediale”, the inner core. Both are made of dense collagen and biopatite (the same mineral found in human bones). But while their chemical makeup is similar, their natural structures are not. In both areas, the cartilage was found to be full of pores and reinforced with thick bumps, which help to absorb pressure and pressure from multiple directions. This is especially important for sharks, as they are constantly in motion. Their spines must bend and bent without breaking as they swim. The cartilage, proves, acts almost like a spring. It stores the energy as the shark’s tail bends and then releases this energy to supply the next stroke. Scientists also noted the presence of tiny crystals that resemble a biopatite needle aligned with collagen strands. This alignment increases the ability of the material to resist damage. The researchers also scored structures of helical fiber in cartilage, the patterns of collagen twisting by helping to prevent cracks from spreading. These structures work together to distribute pressure and protect the skeleton from failure. This type of paved, guideline is something that human engineers have tried to imitate synthetic materials, but nature has perfected it for hundreds of millions of years.

Reckless Vivia MerkerSenior author of the study and assistant professor at FAU Department of Chemistry and Biochemistrythe fau Department of Ocean and Mechanical Engineeringand the fau DepartmentHe explained in a press release that this is a primary example of biommatism: “Nature builds remarkably powerful materials by combining minerals with biological polymers, such as collagen-a process known as biomedicalization. Swimming. Flexible, ideal for medical implants, protective tools or aerospace design.

To try how hard this cartilage is, the team put pressure on tiny pieces of shark vertebrae. In the beginning, they only saw slight deformities smaller than a micrometer. Only after the pressure was made for the second time, fractures were observed and even then the damage remained limited to a single metal layer, implying the integrated material resistance to the catastrophic failure. “After hundreds of millions of years of evolution, now we can finally see how the cartilage works in Nanokrakas – and learn from them,” said Dr. Marianne Porterco-author and Associate Professor at FAU Department. “We discover that tiny mineral structures and collagen fibers meet to create a material that is both powerful and flexible, perfectly adapted to the strong swimming of a shark.

Reckless Stella BatalamaThe Dean of the College of Engineering and Computer Science, agreed: “This research highlights the power of interdisciplinary cooperation. With the concentration of engineers, biologists and scientists, which we have revealed how nature creates powerful but flexible materials. Resistant to the impact.”

This research was supported by a grant by the National Science Foundation granted to Mck. An NSF career award, awarded to the Porter. and seed funding from Fau College of Engineering and Computer Science and Fau Sensing Institute (A-sensuality). The acquisition of an electronic transmission microscope was supported by a grant by the Ministry of Defense/Equipment of the Ministry of Defense/Equipment of the United States.