Conch Shells: Toughness Helps Design Better Protective Gear

By Piyali Roy | May 29, 2017 01:53 AM EDT

Conch shells are designed very uniquely. Their architecture makes it 10 times stronger than the mother of pearl which is called nacre. The internal structure of the conch shell has three levels of hierarchy that form a unique configuration.

This provides it resilience to strong external impacts. If there is a slight crack, the damage will not be enough to break the conch shells, this is because the crack will have to pass through a zigzag matrix, almost like a maze, to break the shell.

The secret behind the resistance of conch shells has been revealed by researchers at MIT. The results of the research have been presented in the journal Advanced Materials, in a paper published by an MIT graduate and a professor, says MITNews. Since they understood that if any crack arises, it would not be easy for it to spread, they thought of replicating the structure in protective gear.

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Even after learning about the structure of conch shells in detail, it was difficult to exactly reproduce the same. Until recently, the Department of Civil and Environmental Engineering developed 3-D printing that allowed to easily replicate.

The team was able to get the same geometry and could design controlled structures from the composite materials of 3-D print. According to, they also conducted tests where they introduce small-length scale features in higher levels of hierarchy, unlike in conch shells to optimize the design.

To get a clear understanding of whether the cracks appeared, if they appeared, how far they spread or not, the researchers conducted tests in a drop tower. When the geometry was similar to the conch shell, tests proved that the crisscross feature prevented crack propagation 85 percent better than the strongest materials. The 3-D printing technology can help design helmets tailor-made for skull sizes of different people. They are trying to develop a new composite material that has a combination of different degrees of strength and flexibility.

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