MONDAY, 15 JANUARY 2024Beetles may be small but some are much tougher than they look. The spooky-looking diabolical ironclad beetle can even survive being run over by a car. These impressive insects are part of the sub-family of beetles known as Zopherinae and their distinctive wing casings, called elytra, can resist up to 149 Newtons of force. Their strength has even influenced the ways we humans create materials and engineer joints in complex structures.
The sutures of these beetles are of particular interest. Sutures are found on the inner edges of both wing cases and shaped like stamp perforations which interlock to join the two elytra together. These sutures dissipate any external pressure across the wing casings, so that no region of the elytra is particularly prone to stress. The wing casings can therefore resist much higher forces before fracturing.
In addition to linkages, the elytra consist of laminated structures. Under tension these structures delaminate, dissipating energy. So, if pressure on the wing cases is great enough to break them, then the laminated microstructures reduce further impact by preventing fissures at the edges. Instead of the elytra disconnecting, their connecting sutures swell and lock them together. This way, when ironclad beetles do break, their elytral connection is reinforced and protects more vulnerable internal structures. Sounds like we puny humans have a lot to learn.
Article by Tasmin Wood
Artwork by Josh Langfield