“Diabolical ironclad beetles inspire tougher joints for engineering applications”

Olivia Cevasco

Mr. Ippolito

AP Biology - C Even

30 October, 2020

Chen, Po-Yu. “Diabolical Ironclad Beetles Inspire Tougher Joints for Engineering Applications.” Nature News, Nature Publishing Group, 21 Oct. 2020, www.nature.com/articles/d41586-020-02840-1.   

                   Bugguide.net 

The article “Diabolical ironclad beetles inspire tougher joints for engineering applications” details a recent scientific study that revealed why the “diabolical ironclad beetle,” also known as Phloeodes diabolicus, is able to withstand pressure 39,000 times its weight (for reference, that’s equivalent to having 600 elephants stacked on top of you). Beetles are arthropods, so their exoskeleton has three layers: a waxy, waterproof epicuticle on the outside and two inner cuticles made of the polysaccharide α-chitin that provide structure for the beetle. The chitin is multilayered, enabling the bugs to absorb energy upon impact and tolerate damage. Compared to other insects, the inner cuticles of the diabolical beetle are much thicker and can withstand extra pressure. These beetles have forewings that are locked together and provide additional protection from predators. In order to determine how the thicker exoskeleton and locked forewings of diabolical beetles enable their strength, the scientists performed compression tests and mathematical simulations on the beetles and found that they can withstand 149 newtons, or 39,000 times their weight. They also discovered that these beetles have three types of structural support between the layers of their exoskeleton. The article’s author says that “Three types of lateral support connect the ventral cuticle [the shell on the beetle’s underside] to the elytra [the beetle’s forewings]: interdigitated, latching and free-standing. The interdigitated joints are the stiffest and strongest under compression, whereas the latching and free-standing supports allow the exoskeleton to undergo some deformation when compressed.” 

Nature.com

Furthermore, the scientists concluded that the hardness of the interdigitated support protects the beetle’s vital organs, and the latching and free-standing supports absorb energy from impact, enabling the beetle to get run over by a Toyota Camry twice [one of the scientists did this out of curiosity] and still survive. 

The diverse support structures of the diabolical ironclad beetle are currently inspiring designs for robots and vehicles that can be both rigid on the surface to protect internal components, withstand high forces and absorb the energy exerted on them. Often, the joints of machines, where metal meets metal, are weak, so scientists are also finding new ways to layer the joints and combine metals. So far, there is already an $8 million project to create metal technologies that mimic this beetle’s structure. Overall, scientists expect to make new materials and designs for future technologies based off of this beetle’s exoskeleton and joints. 

I decided to review this article because we recently learned about the polysaccharide chitin and the structure of arthropods over the summer. This article provided an extensive overview of the beetle’s anatomy but failed to provide significant numerical data from the lab report to support this finding. However, some of the language was hard to understand because the author used words like ‘helicoid’ and ‘elytra’ without defining them, so I had to look up the definitions. Including some graphs or tables from the study would have been a great addition to the diagrams of the beetle in the article.