At present, the only species known on Earth that can fly autonomously are insects, birds, and flying machines made by humans imitating them. This time we talk about the dragonfly in insects, which is simply open and hanging.
Insects, birds, and flying machines appeared one after the other.
Why are tiny insects more capable of flying than birds? This means that in the timeline of biological evolution, insects appeared more than a little earlier than birds, 350 million years ago in the Paleozoic Carboniferous Period, the winged subclass of insects appeared 210 million years earlier than birds (140 million years ago). Dragonflies also appeared around 300 million years ago, and the Dragonflies of the Mesozoic Period 300 million years ago were large and were the "overlords" of the air at that time. A 200 million-year-old fossil of a primitive dragonfly has been found on the northwestern edge of the mainland Junggar Basin, a newly discovered primitive dragonfly with a single wing length of 101 to 102 mm and a wingspan of 210 mm. The early Permian Permian Giant Veined Fly found in the United States has a wingspan of up to 710 mm.
Dragonfly has top-of-the-line flying techniques
1. Long-distance and long-term flight
Dragonflies are powerful and agile flyers, with speeds of 50 kilometers per hour, which can do cross-sea migration, and studies have found that dragonflies fly up to 11,000 miles (nearly 18,000 kilometers).
2. Four ways to fly
Adult dragonflies can move in any direction during flight and suddenly change direction (note that this is any direction that no modern fighter can achieve).
Dragonflies fly in general in 4 ways:
- hover
The forefront wings of the dragonfly flap at 180° and are capable of generating huge lift for hovering or slow flight.
- Fly fast
The hindwings flap 90° ahead of the forewings, providing more thrust to the body and accelerating flight.
- zig
The front and back wings flap at the same time for quickly changing direction.
- glide
The frequency of the wings is synchronized with the airflow, which saves energy.
Dragonflies have a specific body structure
Dragonflies have very thin wings, a network of veins, a quadrilateral primary vein, and a secondary pentagon or hexagon. This structure gives the wings toughness of the dragonfly on a thin and light basis. Unlike most insects, dragonflies have wings that are directly driven, with flight muscles attached to the base of the wings. Dragonflies have a high power/weight ratio, and it has been documented that they accelerate linearly up to 4g when chasing prey and up to 9g when making sharp turns.
When human beings build aircraft, they encounter the problem of "flutter", which refers to the large vibration of the aircraft wings in the uniform air flow due to the coupling of aerodynamic, elastic and inertial forces, if the problem cannot be effectively solved, then the safety performance of the aircraft drops sharply.
Theoretically, dragonflies should also "flutter", but how does a dragonfly that can survive 9g acceleration do it?
It turns out that above the leading edge of each wing of the dragonfly, there is a beautiful thickened part, biologically called the wing mole or wing eye, which is the device used by the dragonfly to overcome the "flutter" during flight, which plays a smooth flight role. If you cut off this black mole and then release it, you will see that it is flying around, not as smooth as before. After people discovered this secret of the dragonfly, they borrowed it to the aircraft, and at the leading edge of the end of the two wings of the aircraft, the balance rod under the wings was made, which could maintain the balance of the aircraft in flight!
Eliminates "fluttering" wing moles
As a result, scientists modeled on wing moles to add a similar structure to the wings of the aircraft, eliminating "flutter".
Dragonfly wings have nano antibacterial properties
The nanostructures of dragonfly wings kill bacteria by tearing them into pieces, which in turn insulates them from bacterial infestation. By using electron microscopy to observe the nanostructures on the surface of dragonflies' wings that give their wings an incredible antibacterial property, researchers hope they can make antibacterial surface coatings that will benefit medical spaceflight.
ultrastructure
Dragonfly's structure and flight technology make it the hegemon of the flying world, the current UAV still can not fly like the dragonfly, but when scientists uncover all the secrets of the dragonfly, I believe that in the near future, a new generation of bionic flying vehicles will appear in front of people.