The hexagonal plates of the boxfish's carapace have been identified by engineers as a potential source of inspiration for body armour, robots and flexible electronics.
The characteristically boxy fish has a shell made up of interlocking hexagonal scales, complete with a raised star-like structure in the centre that distributes stress across the surface. After dissecting the scales, researchers discovered a flexible inner layer of interlocking collagen fibres that are tough to penetrate.
"The boxfish is small and yet it survives in the ocean where it is surrounded by bigger, aggressive fish, at a depth of 50 to 100 meters," said Wen Yang, the lead author of the paper describing the discovery. "After I touched it, I realized why it can survive – it is so strong but at the same time so flexible."
35 million years of armour
The connections between the plates offer similar advantages – on impact, the zig-zag patterns lock together and keep the carapace from breaking apart. That's notably different to armour seen elsewhere in nature, which tends to rely on overlapping scales for protection.
"We are currently investigating what mechanical advantage [this structure] might provide," said Steven Naleway, a co-author on the paper. "We know that the boxfish has survived for 35 million years with this armour, so the design has proved very successful in nature."
Image credit: Duncan Geere // CC BY-SA 3.0