Earwigs unfurl their wings in ways that defy the rules of origami. To some, they might be no more than pesky garden insects and occasional nuisances. But upon looking more closely, their anatomy might just inspire cutting-edge technology.
Earwigs stay grounded most of the time and don't really fly that frequently. As a result, they keep their wings hidden in a small package with a surface area over 10 times smaller than their wings when fully revealed. They do this by folding their wings origami-style.
How An Earwig Folds Its Wings
This insect has springy wing joints that allow them to bypass certain mathematical constraints that typically limit the way two-dimensional surfaces can be folded, according to a new study that's just been published in the Science journal.
Looking at the rules of origami, earwigs' wing-folding mechanisms should be impossible, says study coauthor and mechanical engineer Andres Arrieta. The theory of origami states that the folded material is very rigid, but the joints in an earwigs' wings have resilin, a form of rubbery polymer that lets the insect perform very complicated folding moves that is impossible to do on an origami structure.
The wing design, when in its open and locked state, remains firm and stiff, and as a result doesn't require stability or muscle power to remain stable. Then, when an earwig is ready to draw back its wings, it does so with just one "click," and the wings promptly retract without muscle actuation.
The researchers, who hail from ETH Zurich and Purdue University, have successfully created an imitation of an earwigs' wings, which is supposed to operate using the same principle of the insect's folding mechanisms.
To achieve this, they looked at several elements — what makes the wing stable, and what makes it fold, for example — and created computer simulations with their findings, and from there they were able to create a 3D-printed 4D object made up of four stiff plastic plates attached to each other by virtue of a soft elastic joint — just like an earwigs' wings.
Foldable Devices
There's a lot of work to do, of course. But the biological marvel of an earwigs' wings might inspire the design of foldable devices in the future, especially consumer electronics and airplanes. The aerospace industry can also benefit from that design principle. Imagine a spacecraft or probe that can start out as very small objects but then unfurl fully once it reaches its target destination.
