Natures wonders: insect wings are almost damage proof (Introduction)

by David Turell , Monday, March 22, 2021, 18:50 (1124 days ago) @ David Turell

The wings will hit flower petals, branches as the fly in for pollen, but the wings survive::

https://phys.org/news/2021-03-insect-wings-collisions.html

"About once a second wings of foraging bees collide with small obstacles such as flowers, leaves or branches during flight without suffering major long-term damage. At the same time, they withstand aerodynamic loads effortlessly—yet the fragile structures make up just two percent of the total mass of an insect's body....they show several special features in the wing structure, thanks to which they are both stable and flexible and can thus adapt to different needs.

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"Dragonfly wings consist of rigid vein network and membranous areas between them. The veins are connected by flexible joints. These allow the wings to deform under relatively small loads. Under higher loads, microscopic spikes in the proximity of the microjoints interlock and stop the deformation. They increase the stiffness to support the wing against aerodynamic loads. And finally, special zones in the wing reversibly buckle to a certain extent in the event of a collision with an obstacle. "Thanks to these three design strategies, insects can change the characteristics of their wings and thus fulfill several functions at the same time," says Ph.D. student Ali Khaheshi, first author of the study.

"But the research team went one step further: to test whether their theory about the design strategies of insect wings also stands up to practical application, they applied it to an aircraft model with a size of 8 x 5 x 1.1 cm and a weight of 3.8 g. They 3D printed it from PLA / PLH filament and performed both collision and free fall tests. It turned out that the wings survived the collisions, while conventionally constructed aircraft models broke. In addition, they performed static, dynamic and fatigue tests with slightly modified constructions in which they omitted one of the design strategies in each case. "These experiments confirm that it takes all three design strategies in combination to gain the observed mechanical performances," says the engineer and materials scientist Khaheshi. This could also work with other, higher-quality materials, the researchers assume.

"The main point is, that the strategies are already integrated into the structure of the wings and function fully passive, there is no requirement for complex control strategies. "Such insights from biology could help us to construct technical systems that adapt autonomously to extreme or unforeseen situations—for example, in environments where humans cannot actively intervene, such as in space missions," says Dr. Hamed Rajabi."

Comment: As usual God designs teach us how to do it. I think insect wings were designed this way from the beginning of flying insects that feed on plants. Why? Because such a complex construction can not develop stepwise.