What makes the diabolical ironclad beetle (the insect's actual common name) so indestructible? To find out, researchers at the University of California, Irvine and their colleagues repeatedly drove over them with their cars. Yes, the creepy crawlers survived the tire test and countless other more exacting compression tests in the laboratory. After years of research, materials scientist David Kisailus and grad student Jesus Rivera determined that its the combination of the material and structure of the beetle's exoskeleton which is different than other beetles. They reported their findings in this week's issue of the scientific journal Nature. Now, the scientists are taking inspiration from the diabolical ironclad beetle's unique exoskeleton to develop new kinds of carbon fiber-reinforced plastic fasteners that are stronger than traditional counterparts. From UC Irvine:
"The ironclad is a terrestrial beetle, so it's not lightweight and fast but built more like a little tank," said principle investigator and corresponding author David Kisailus, UCI professor of materials science & engineering. "That's its adaptation: It can't fly away, so it just stays put and lets its specially designed armor take the abuse until the predator gives up."
In its desert habitat in the U.S. Southwest, the beetle can be found under rocks and in trees, squeezed between the bark and the trunk – another reason it needs to have a durable exterior[…]
[The researchers] found that the diabolical ironclad beetle can withstand a force of about 39,000 times its body weight. A 200-pound man would have to endure the crushing weight of 7.8 million pounds to equal this feat.
Conducting a series of high-resolution microscopic and spectroscopic evaluations, Rivera and Kisailus learned that the bug's secret lies in the material makeup and architecture of its exoskeleton, specifically, its elytra. In aerial beetles, elytra are the forewing blades that open and close to safeguard the flight wings from bacteria, desiccation and other sources of harm. The ironclad's elytra have evolved to become a solid, protective shield.
image: Jesus Rivera / UCI