Robotic Flying Jellyfish

Have you ever wondered whether it is possible to glide through the air just as jellyfish swim through water? Scientists at the German company “Festo” have not only answered this question positively, but have built a device that does exactly that. The “AirJelly”, which flies through the air with exceptional ease and accuracy, imitates the motion of jellyfish in water and adopts the marine invertebrate’s propulsion principles. The developers say it is utterly surprising that until today, the analogy between water and air environments has not provided inspiration for adapting the propulsion mechanisms of marine creatures to the aviation sector.

The “AirJelly” is a remote radio-controlled airborne jellyfish with a central electric drive unit and an intelligent adaptive mechanism. Weighing slightly over 1.3 kilograms and measuring 2.20×1.35 meters, this machine consists of a helium-filled ballonet, which can be filled with a volume of 1.3 cubic meters of helium. One cubic meter of helium can support lifting approximately one kilogram, and therefore, the “AirJelly” is limited to a weight of no more than 1.3 kilograms.  

AirJelly’s sole source of power are two rechargeable lithium-ion polymer accumulator batteries rated at 8 V and 400 mA. A connected central drive unit transmits the power to a bevel gear and then to eight spur gears, which power eight shafts that activate cranks – these, in turn, move the jellyfish’s eight tentacles. According to the inventors, the structure of the tentacles was derived from the functional anatomy of a fish’s fin. “It consists of two alternating tension and pressure flanks movably connected by ribs. If a flank is subjected to pressure, the geometrical structure automatically bends in the direction of the applied force. Together, the tentacles produce a peristaltic forward motion similar to that of their biological model”, explained Festo. 

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AirJelly’s motion in the air is controlled by weight displacement. A 55cm-long pendulum, which is set by two actuators, defines the system’s centre of mass by the direction of its motion, causing the airborne jellyfish to “swim” in a certain direction. The scientists say that by this forward motion, AirJelly can move in any spatial direction, making it the first indoor flight device with a peristaltic drive. “With this exhibit, Festo is demonstrating that a central electric drive unit in combination with an intelligent mechanism opens up fascinating opportunities in propulsion systems for lighter-than-air flight”, said the company. 

The AirJelly is not the first project in which Festo has combined nature-inspired principles; some of the company’s most impressive projects include the “Airacuda”, a remote controlled pneumatically driven fish, and the “AirRay”, a remote-controlled ballonet filled with helium and constructed with a flapping-wing drive mechanism. The company has also created the “Airic’s Arm”, a mechanical arm, operated by fluidic artificial muscles.    

More information on the AirJelly can be found here, and a video demonstrating the invention can be found here.