The “Diabolical Ironclad Beetle”, also known as “nosoderma diabolicum”, is a beetle of the Zopheridae family living on the western coast of the United States, and it has scientists baffled with the strength of its outer shell.
Engineers from the University of California, Irvine (UCI) have teamed up with a team from Purdue University to figure out what makes the beetle’s exoskeleton a structural marvel.
The scientists took some poor beetles in for testing and subjected them to a compressive force of 150 Newtons, which is about 39,000 times the insect’s body weight. This is the point where the first fractures appear at the outer shell, so it’s the maximum force it can take. Notably, a car tire running over the ironclad beetle exerts 100 Newtons of force, so it can’t crash it. It goes without saying that trying to do any damage to that beetle by stepping on it is impossible.
The university teams took CT scans to figure out what individual components make up the exoskeleton, as well as how exactly are the forces distributed when the plates lower down on the insect. The team even 3D printed the individual parts of the shell to further experiment without troubling more real-life insects.
What the scientists found was that there’s a complex delamination process going on for the structure that keeps the blades interconnected. The blades also lock in place when under pressure, so they won’t pull out. The most fragile point is at the neck, but force distribution channels the pressure away from there.
The value in that for engineers is that they can use some of the Diabolical Ironclad Beetle’s strategies to assemble components that are able to support huge loads as a set, and not individually.
Also, some elements in the beetle’s exoskeleton could help aerospace engineers take away fasteners from turbine designs and replace them with an artificial inter-facial suture.
Source: Purdue University
Media Credit: Jesus Rivera, Kisailus Biomimetics and Nanostructured Materials Lab, University of California, Irvine