The devil’s sturgeon beetle rarely breaks. You can hit it, step on it, or run around in a car.
Now scientists know why this beetle’s outer wing case, known as the beetle, is so tough. It consists of a series of puzzle parts that fit seamlessly. The geometry and internal structure of this “jigsaw” design increases the strength of the beetle armor.
Sturgeon beetle (Phloeodes Devil) It is about 0.6 to 1 inch (15 to 25 mm) long and is found in forest habitats in western North America and lives under tree bark. Their ancestors were able to fly, but the sturgeon beetles long ago lost their ability to fly, and the elytra wings fuse together to form a shock-resistant shield.
Entomologists are so accustomed to the strength of these barriers. Efforts to secure sturgeon beetle specimens for mounting, display, and storage often end up with unpunched insects and a pile of bent steel pins, scientists wrote in a new study published online in the journal today (October 21). . nature.
Researchers performed compression tests on the beetles to see how much force they can withstand before the shield breaks. They found that the “iron” beetle could resist up to 149 Newtons or 33 pounds of continuous force. (15 kilograms). This was about 39,000 times the weight of the beetle and more than twice the strength of other species of land beetles.
Microscopic analysis of the exoskeleton section revealed a lateral support structure that evenly distributes the weight of the beetle’s back and protects the organs by making some parts of the beetles stiffer than others. And more reinforcement was made at the seams where the scab wings were joined.
In the flying relatives of the irony beetle, the elytra wing notches are “tongue and groove design”, allowing the lower wing to gently open, close and release for flight, researchers report. However, in sturgeon beetles, fused elytra wings fit together like pieces of a jigsaw puzzle along the length of the abdomen of the insect. The protruding parts of these mating parts, called blades, distribute the stress to the exoskeleton to prevent cracking.
When the researchers 3D printed the sample to test the strength of the puzzle connection, they found that the five-bladed suture was the stiffest and could withstand the heaviest loads. Scientists have also detected a layered microstructure in the cross section of the blade that dissipates more stress from the most vulnerable parts, protecting the narrow “necks” of the puzzle pieces that fit together from fractures, and actually making the pieces more secure.
Uncovering the biological structures that make the sturgeon beetle exoskeleton virtually unbreakable could help engineers design structures that are more impact resistant, and the researchers tested them with their own 3D-printed designs.
Scientists write in the study, “We demonstrate this by making peristaltic sutures from biomimetic composites that have a significant increase in toughness compared to commonly used engineering joints.”
Originally published in Live Science.