The dead bird was reborn as a drone, and will fly with the flock of birds. I wonder if other birds can find out that it died a long time ago...

The dead bird flapped its wings again and soared over a university campus.

These birds with clumsy flying postures are actually drones, or more precisely, drones covered with the skin and feathers of dead birds. The researchers gave this project of "rebirth" of dead birds into drones a name - Phoenix.

The drone project is called Phoenix. Image credit: Mostafa Hassanalian

"Instead of making drones out of artificial materials, we redesigned dead birds into drones," said Mostafa Hassanalian, an associate professor of mechanical engineering at New Mexico Tech and the engineer who led the project.

Hassanalyan has been researching drones for the past decade or so. While studying the optimal flapping frequency and wing shape for flapping-wing drones, he unknowingly entered the field of biomimicry because he found that artificial materials could not replicate the actual flight of birds.

Image credit: Mostafa Hassanalian

"If we used artificial materials, we wouldn't be able to get that perfect flapping motion," Hasanalyan said.

Phoenix Nirvana becomes drone

No birds were harmed in the process of making these drones. The research team purchased bird wings online and worked with a taxidermy team to obtain whole birds. The birds used included pigeons, pheasants, hummingbirds and crows, and each bird cost about $200.

With real bird wings, tail, head and torso, the researchers designed a drone control component and installed it into the bird's body, and the dead bird can be "resurrected".

Image credit: Mostafa Hassanalian

In the lab, the reconstructed bird drones are tested in a flapping simulator to see how much stress the wings can withstand and how fast they can reach when flying. After each flight test, the data is added to a computer program, allowing the researchers to analyze and continuously improve the flight technology and study how to keep these drones in the air for longer periods of time.

After a series of tests, the researchers found that compared with wings made of artificial materials, these dead bird wings are more efficient. The same wing can generate force in multiple directions. Conventional drones need to be equipped with different components for each force to achieve similar effects.

Image credit: Mostafa Hassanalian

Birds have elastic ligaments between their feathers and flexible bones, which allow them to move cleverly as wind direction changes. Currently, it is very difficult to design and manufacture wings with the same aerodynamic efficiency using artificial materials.

Image credit: Mostafa Hassanalian

Outside, the drone flapped its wings in Hasanalyan's hands, and after being thrown into the air by someone, it was able to fly forward. Currently, it can only fly for a maximum of 20 minutes , and the research team said they are studying energy-saving strategies to extend the flight time.

Image credit: Mostafa Hassanalian

This dead bird drone is still just a prototype, but looking at it flying from a distance, it seems to be still alive and well.

Does the color of a bird also affect its flight?

Many birds are good at flapping their wings, but some birds flap their wings less frequently but are very capable of flying. For example, the albatross, an "efficient flying master", can glide more than a thousand meters over the vast ocean without flapping its wings at all.

Like many other seabirds, albatrosses have black wings on the top and white wings on the bottom. The black color absorbs more solar radiation, so the top side of the wing gets hotter than the bottom - the top surface is about 10°C hotter than the bottom.

Wandering albatross (Diomedea exulans) Image credit: JJ Harrison

The air pressure is lower in warmer areas, while the air pressure is higher under the wings, which gives the albatross extra lift, just like the wings of an airplane, making it easier to fly. Inspired by the albatross, the researchers first tested fixed-wing drones and found that color does affect flight efficiency. They are now studying how the color and pattern of bird feathers affect the flight of flapping-wing aircraft.

After the endurance is improved, these dead bird drones will also enter real bird flocks in the wild for experiments. In order to better understand the formation and flight patterns of migratory bird flocks, the researchers built a large bird cage in the university laboratory. In the bird cage, a small group of bird drones flapped their wings in place against the wind.

They fly in a V-formation in place. Image credit: Mostafa Hassanalian

More “social” when monitoring

Dead Bird drones are also equipped with miniature cameras, microphones and other basic equipment that allow them to perform surveillance missions. When the technology matures, Dead Bird drones can be used to better study wildlife and track deforestation and poachers.

“I’m watching you” Photo credit: Mostafa Hassanalian

Traditional drones often cause problems when used to monitor wildlife. For example, birds that are frightened by drones may abandon their nests, exposing their young to danger. In addition, birds sometimes attack drones or collide with drones during flight, causing injuries to the birds.

A more realistic and quieter bird drone would be better able to blend in with the natural environment and allow for close-up observations. Deadbird drones with improved gear components could also be made quieter. They could also be used to guide birds away from airports to prevent bird strikes.

Image credit: Mostafa Hassanalian

Compared with traditional fixed-wing UAVs and rotorcraft UAVs, flapping-wing aircraft have many advantages, such as low noise, low energy consumption, better hovering and low-speed flight capabilities, and no need for a runway for takeoff and landing.

Now, by using the parts of dead birds, the production of flapping-wing drones can directly save the troublesome process of making mechanical wings. For such local materials, Hasanalyan believes that they are conducting "reverse engineering."

Later, they plan to add legs to the birds so that the drones can stay aloft and conduct surveillance without consuming too much power.

No legs yet. Photo credit: Mostafa Hassanalian

“The biggest challenge we have right now is that we don’t know how other birds will react,” Hassanalyan said. He also can’t be sure whether the raptors will try to attack the drones if they see them.

Emmm, are you sure you don't have to worry about being attacked?!

References

[1] Anil Oza, RGB (2023). Once a satirical conspiracy theory, bird drones could soon be a reality. NPR. Retrieved from https://www.npr.org/2026/01/01/1198916182/birds-drones-engineer-biomimetics

[2] Melnick, K. (2023). Dead birds are flying again — this time, as drones. Washington Post. Retrieved from https://www.washingtonpost.com/nation/2023/04/20/dead-birds-drones-fly-experiment

[3] Funnell, R. (2023). Are Taxidermy Drones Made Of Dead Birds The Ultimate Spies? IFLScience. Retrieved from https://www.iflscience.com/are-taxidermy-drones-made-of-dead-birds-the-ultimate-spies-69649

[4] Nalewicki, J. (2023). Taxidermy birds are being turned into drones. Livescience. Retrieved from https://www.livescience.com/animals/birds/taxidermy-birds-are-being-turned-into-drones

[5] Landymore, F. (2023). Scientists Turn Dead Birds Into Ghoulish Drones That Can Actually Fly. Futurism. Retrieved from https://futurism.com/the-byte/dead-birds-drones-that-fly

[6] Hassanalian, M. (2022, September 22). Festival of Cranes 2022-December 1 to 3, New Mexico Tech. Youtube. Retrieved from https://www.youtube.com/watch?v=cm4k9voE1EM

Planning and production

Source｜Bring Science Home (id: steamforkids)

Author: Cloud, editor of Everything Magazine

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Editor: Yang Yaping