First of all, our bionics experts took a close look at the fins of the manta ray. Although this creature lives in water, its large pectoral fins beat up and down like wings when it swims. We transferred this principle to the Air_ray in 2007. The flow-optimised design of the artificial ray increases aerodynamic efficiency, while the active torsion of the wings ensures that their full force is used. A servo motor pulls alternately on the two flanks in a lengthwise direction and thus moves the wings up and down. With an additional servo drive, the beating wing can be rotated around its transverse axis, so that the Air_ray can also be manoeuvred backwards. Thanks to its lightweight design, the uplift provided by helium and its beating wing drive with Fin Ray Effect®, it moves through the air just its natural role model moves through the water.
A similar concept is also behind the AirPenguins developed in 2009. Their flying technology is very close to the swimming technique of their biological models. The passively twisting wings allow both forward and reverse thrust to be generated.
The AirPenguins are the third group to fly autonomously and float within a defined airspace, which is detected by ultrasound transmitting stations. The penguins can move freely within this space.
A microcontroller gives it the opportunity to explore this space autonomously or according to specific rules.
Building on this, in 2011 we deciphered the secret of bird flight and presented the SmartBird. This bionic technology platform, inspired by the herring gull, can start, fly and land by itself – without additional drive.
Not only do its wings beat up and down, but they also twist in a specific manner. This is done by an active articulated torsion drive, which, in conjunction with a complex control system, achieves previously unattained efficiency levels in flight. Continuous diagnostics ensures a safe flight. While the SmartBird is flying, data such as the wing position, the wing torsion or the status of the battery are recorded and checked in real time by the software.
However different the flying behaviour of animals in the natural world may be, when transferring it to technology, the major challenges are always the lightweight design and functional integration. With the BionicFlyingFox, whose articulation points of the heavily loaded kinematic system are all on one plane so that the wings can be folded like scissors, Festo has now deciphered all the different types of flying found in the animal world. But nature provides many other unique solutions which will inspire the bionics team to find new technical solutions in the future.