A Review of Bionics for Bird Flight and Potentially Applicable Mechanisms

Abstract

Researchers from different disciplines have been learning from bird flight and were inspired to design and optimize novel flying machines. Though lots of bird bionics have emerged, the mechanisms of different bird flight capabilities still remain unknown. By studying the mechanisms of some birds’ special flying abilities, researchers can design new flying machines easier and better. The advancement of studies on bird flight bionics in recent years is fast. Rich discoveries have been reported by scholars about the mechanisms of bird flight from different disciplines. However, there is a lack of review efforts that combine bionics for bird flight and potentially applicable mechanisms. Therefore, a review of recent publications reporting bird flight bionics and the underlying mechanisms of bird flight is needed. Here we reviewed 41 recent studies about bionics for bird flight. We analyzed these bird flight bionics from three perspectives - energy efficiency, material characteristics and signal control. We found that energy consumption per mile of bionic machines is still higher than birds in nature and the energy efficiency can be improved by optimizing aerodynamics. The studies about materials characteristics mainly investigated how to mimic the feather of birds, while how to use shape memory materials to bionic the muscle of birds is a new direction. Finally, we found very few studies bionic the signal processing systems of birds. With the increasing knowledge of neuroscience, if we can mimic the signal control circuits in bird’s brain, it will help us a lot on designing more agile flying machines. We also summarized 20 studies about the mechanisms of bird flight, three main categories of research have been identified, i.e., flight agility bionics, long-distance flight bionics and stabilizer bionics. Some special species give us good examples to imitate in these three categories, such as bee hummingbirds, ibises and pigeons. These potential mechanisms may provide us new direction for future bionics for bird flight. By summarizing these bird flight bionics and predicting applicable mechanisms, this review identified new directions to advance the current status quo in the bionics domain, which will eventually benefit our real life, such as controlling drones to fly in groups for shipments or achieving stable hovering in the air for aerial photography.