The diabolical ironclad beetle is practically indestructible. Now scientists know why

You can accidentally stump on a diabetic ironclad beetle and it won’t even pinch. Go one step further – drive in your car – and it won’t cause any trouble to the critic, either. Its exoskeleton is the most difficult in the animal kingdom. And scientists now believe they know why.

In a study published in the journal Nature on Wednesday, researchers have unraveled the mysteries of the surprising crush-resistance of the diabolical ironclad beetle and demonstrated how the new ultra-tough material could benefit the beetle’s biology.

At a glance, the beetle looks impressive: a dark, bumpy X os skeleton that looks like a fiery rock. But hiding beneath its humdrum exterior is one of the few structural surprises built by Evolution. Many species of beetles can fly and have a protective, tough shell inside their wings. Flying is a great protective mechanism for beetles, with which they can get rid of predators, but ironclad does not have wings and regularly plays dead, relying on its exoskeleton to keep it safe.

“Ironclad is a terrestrial beetle, so it’s not lightweight and fast but a little bit built like a tank,” said David Kisalius, a professor of materials science and engineering at the University of California, Berkeley, who co-authored the study. A publication. The exoskeletal of the beetle is very tough, it has also presented some issues for the oncologists hoping to show them – it is difficult to put a pin through the ironclad.

To study the small tank, a member of the research team, Jesus Rivera, captured the beetles and brought them back to the laboratory. First, researchers found that the beetle’s exoskeleton can withstand a force of about 150 Newtons – 39,000 times its body weight. The other three species of terrestrial beetles were only half as resilient.

But why is this particular exoskeleton so strong? The research team looked at beetles using a 3D imaging technique called microcomputed tomography, which acts like an X-ray for the whole organism. They focused on Ironclade’s Ultra.

It seems unusual to have an ultra for an iron bar. After all, it is a land-dwelling beetle that cannot fly. But it has evolved from a beetle that, at some point, can do it, and its ultra is important for its exoskeleton power. They have blended together very significantly to create winding, turning sewing.

Researchers have described it as “jigsaw puzzle pieces”. Lock the two pieces together and the probable point of failure is on the “neck” of the jigs piece. But the team did not find a catastrophic failure using Siven’s study and computer simulations under a high-powered microscope. Instead of cracking open, rather than transferring stress across the region, Siven held on. That’s important – it protects the beetle’s throat

Also, the chemical composition of Ironclad’s Eletra is slightly different from that of flying beetles. It appears to contain an excess of protein, which may increase the hardness of the insect.

Researchers went further and examined how this exoskeleton geometry could enable the development of rigid materials. They took lessons learned from beetle CVs and made some carbon fiber jigsaw pieces to test mechanical strength in real world application – fasteners used in aerospace engineering. Pieces of jiggle that mimic an iron bar perform best.

“This work shows that we will be able to migrate using powerful, brittle materials that can be both strong and tough by breaking down broken ashes,” said Pablo Zavattieri, a civil engineer at Purdue University. Study.