Science

Conch-inspired material may find use protecting humans

Conch-inspired material may fi...
Conch shells may be pretty, but they're also tough
Conch shells may be pretty, but they're also tough
View 2 Images
Testing proved that the geometry with the conch-like, criss-crossed features (right) was substantially better at preventing crack propagation
1/2
Testing proved that the geometry with the conch-like, criss-crossed features (right) was substantially better at preventing crack propagation
Conch shells may be pretty, but they're also tough
2/2
Conch shells may be pretty, but they're also tough

Although sea shells of various types have been studied as sources of inspiration for impact-resistant manmade materials, the conch shell is known for being particularly tough. And while the reason for its toughness was already understood, it hadn't been replicated using engineered materials – until now, that is.

The conch shell is made up of three layers, with the grain running in a different direction in each one. This means that when it's subjected to an impact, cracks can't just run straight through it. Instead, they have to follow a sort of zig-zagging path, which dissipates much of their energy.

Using a 3D printer, a team at MIT has reproduced that structure out of composite materials. When subjected to drop tests (in which a weight is dropped on samples), the conch-inspired material was 85 percent better at preventing crack propagation than samples of the base material without the conch-like structure. It was also 70 percent better than a traditional fiber composite.

Testing proved that the geometry with the conch-like, criss-crossed features (right) was substantially better at preventing crack propagation
Testing proved that the geometry with the conch-like, criss-crossed features (right) was substantially better at preventing crack propagation

It is now hoped that by subtly tweaking the structure of the material, it could be optimized for applications such as lightweight body armor.

The study was conducted by MIT graduate student Grace Gu, postdoc Mahdi Takaffoli, and McAfee Professor of Engineering Markus Buehler. There's more information in the video below.

Source: MIT

Secrets of the conch shell and its toughness

1 comment
Gregg Eshelman
What's new about this? It's common practice when laying up fiber reinforced composites to run the fibers in different directions in each layer.