The insect-inspired fan design offers a wide range of applications.

A highly sophisticated folding mechanism employed by a group of insects for at least 280 million years will be available for a wide range of applications, thanks to a design method developed and tested through multidisciplinary research by engineers and paleobiologists.

According to an article published in the procedures of the National Academy of Sciences Today, researchers have recreated the complex and collapsible folding mechanisms found in earwigs’ wings with an origami-inspired geometric method that has potential applications in different fields of engineering.

The earwigs’ rear wings automatically fold under the small leather front wings when the animal is not in flight, employing a specialized folding pattern that reduces the surface area by ten to 15 times or more depending on the species. This is the most compact folding wing found in insects and gives ear muffs ground mobility for an flying insect like no other. With the wings protected and their abdomen completely flexible, the earwigs can twist on the ground and other narrow spaces, as well as use their characteristic rear darts.

Despite the excellent engineering potential of the earwig wing and its unique properties, one method of designing its complex folding patterns had not been solved, making practical applications difficult.

“The method for designing our earwig-inspired fan is based on the ability to fold flat on the origami model, a mathematical theorem that explains how fold patterns can be folded to form a flat figure,” explains lead author, Dr. Kazuya Saito, an engineer from the Kyushu University School of Design who specializes in bioinspired deployable structures. “Our earwig fan can be designed using classic drawing techniques, but we have also developed and released software that can automate the process based on application requirements.”

The geometric requirements for the new design method were informed by tomographic images on folded rear fins.

The researchers predict that their earwig-inspired fan will see multiple applications for folding structures, of varying sizes and materials, in highly compact shapes that can be transported and deployed efficiently. These can include everyday items, such as fans or umbrellas, as well as multiple structures for use in architecture, mechanical engineering, and the aerospace industry, such as drone wings, antenna reflectors, or energy-absorbing panels.

On the other hand, the research provides new insights into evolutionary biology, as the new design method can also recreate the 280 million-year-old earwig relatives’ wing-folding mechanism.

“The wings of modern earwigs show little variation in their approximately 2,000 living species, with folding shapes and patterns that remain remarkably stable throughout evolution due to their specialized function,” says Dr. Ricardo Pérez-de la Fuente, a insect paleobiologist at the Oxford University Museum. Natural History and co-author of the work. “However, a long-extinct group of insects, the Protelitropterans, possessed fan-like wings similar to earwigs, but different enough to test the consistency of the new design method. Our work shows how paleontology may be of interest for practical applications. “

The new method defines geometric constraints so that the fan-shaped wings of both earwigs and their prototelitropic relatives in deep time remain functional. This allowed the researchers to project hypothetical and extinct intermediate forms between the two groups, shedding light on possible evolutionary pathways that could have led to the sophisticated wings of modern earwigs.

This research represents a multidisciplinary effort between evolutionary engineers and biologists from Japan and the United Kingdom. Samples from the Oxford University Museum of Natural History and the Museum of Comparative Zoology (Harvard University) provided data for building and testing the geometric method, highlighting the value of natural history collections, even for next-generation applications. .

“Nature has always been an eternal source of inspiration,” says Professor Zhong You, of the Department of Engineering Sciences at Oxford University and co-author of the paper. “Bioinspired technologies continue to offer some of the most efficient and sustainable ways to meet many of the challenges of the future.”