Recent scientific investigations into the wing dynamics of flying animals have led to remarkable advancements in robotic technologies. Birds and bats use powerful pectoral and wing muscles to control their wing movements. However, the mechanisms behind the wing movements of many insects remain poorly understood. Researchers at École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland and Konkuk University in South Korea have recently made strides in this area by studying rhinoceros beetles, herbivorous insects known for their robust wings.

Rhinoceros beetles inspire these researchers because of their unique way of deploying and retracting their wings. Their discoveries, published in the journal Nature, reveal that these beetles use passive mechanisms to control their wing movements. Unlike birds and bats, which rely heavily on muscle power, rhinoceros beetles employ their hardened forewings, called elytra, to deploy and retract their hindwings passively. This happens without substantial muscular effort, providing an innovative model for designing flapping-wing robots.

Using these findings, the researchers have created a new flapping microrobot that mimics the beetle’s passive wing mechanism. The robot’s design includes foldable wings that deploy and retract without complex actuators. Lead author Hoang-Vu Phan highlighted the simplicity of this design, where elastic tendons at the “armpits” of the robot facilitate passive wing movements. This design is attributed to more stable flight and the ability to fold its wings at rest, making it efficient and versatile for various applications, including search and rescue missions in confined spaces.

Given their limited muscle availability, future studies explore whether other insects employ similar passive strategies. The team’s research promises to advance the design of flying microrobots and enhance our understanding of insect biomechanics. The microrobot holds potential for various real-world applications, from studying insect flight mechanics to navigating challenging environments that conventional drones cannot. Each innovation brings us closer to creating more efficient, insect-like flying machines while offering new engineering and biological research tools.

References

• Phan, H.-V., Park, H. C., & Floreano, D. (2024). Passive wing deployment and retraction in beetles and flapping microrobots. Nature, 1–6. https://doi.org/10.1038/s41586-024-07755-9
• Fadelli, I. & Tech Xplore. (2024, August 4). A flapping microrobot inspired by the wing dynamics of rhinoceros beetles. Tech Xplore; Tech Xplore. https://techxplore.com/news/2024-08-microrobot-wing-dynamics-rhinoceros-beetles.html