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Jellyfish drones coming? New flying machine moves like sea creature

Jan. 26, 2014
Courtesy of The Royal Society 
and World Science staff

Sci­en­tists have de­vised a lit­tle fly­ing ma­chine that moves like a jel­ly­fish in wa­ter. The only prob­lem is it can’t car­ry the weight of a bat­tery for the mo­tor, so it has to re­main at­tached to a ti­ny cord—but that should change, the de­sign­ers pre­dict.

A vi­deo of it is on YouTube.

Real jellyfish. (Image credit: wwarby)


Tech­nol­o­gy of­ten mim­ics na­ture in its quest for ef­fi­cient, sta­ble and ma­neu­vra­ble flight. En­gi­neers have of­ten tak­en in­spira­t­ion from in­sects in the past 20 years, but ma­chines with insect-like flap­ping wings have suf­fered some sta­bil­ity prob­lems.

The team be­hind the new craft searched for in­spira­t­ion in the seas in­stead. They de­vel­oped a craft with four flap­ping wings that are pushed in and out in pa­irs. Wings on op­po­site sides of the ma­chine flap si­mul­ta­ne­ous­ly, with the sec­ond pa­ir of wings fol­low­ing close be­hind. 

This al­lows the cone-shaped ma­chine to gen­er­ate lift. “This de­sign is rem­i­nis­cent of the swim­ming mo­tions of jel­ly­fish,” wrote the sci­en­tists, Leif Ristroph and Ste­phen Chil­dress of New York Uni­vers­ity. They sug­gest the wing mo­tion gen­er­ates a je­t flow­ing down­wards, push­ing the ma­chine up, like the domed “bell” jel­ly­fish use to pro­pel them­selves.

The find­ings are pub­lished in the Jour­nal of the Roy­al So­ci­e­ty In­ter­face.

The team came up with the con­cept through ex­pe­ri­ments at the uni­vers­ity’s Ap­plied Math Lab, con­clud­ing that cone- or pyramid-shaped ma­chines might be able to achieve sta­ble hov­er­ing by flap­ping aer­o­dy­nam­ic wings with no need for ex­tra “sails” or “tails” of­ten needed for sta­bil­iz­a­tion.

The ma­chine, made of car­bon fi­ber loops and thin my­lar film for the wings, is pow­ered by a ti­ny mo­tor weigh­ing just 1.1 grams, half as much as a dime. The wings are just 8 cm (3 inches) long.

The mo­tor is ex­ter­nally pow­ered, but the team pre­dicts tweak­ing the wing size would boost lift and al­low for an on­board bat­tery. The study is “a step to­wards a fea­si­ble de­vice,” they wrote, sug­gesting that such small crafts could be used for sur­veil­lance, re­con­nais­sance and traf­fic and air qual­ity mon­i­tor­ing.


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Scientists have devised a little flying machine that moves like a jellyfish in water. The only problem is it can’t carry the weight of a battery for the motor, so it has to remain attached to a tiny cord—but that should change, the designers predict. A video of it is on YouTube. Technology often mimics nature in its quest for efficient, stable and maneuvrable flight. Engineers have often taken inspiration from insects in the past 20 years, but machines with insect-like flapping wings have suffered some stability problems. The team behind the new craft searched for inspiration in the seas instead. They developed a craft with four flapping wings that are pushed in and out in pairs. Wings on opposite sides of the machine flap simultaneously, with the second pair of wings following close behind. This allows the cone-shaped machine to generate lift. “This design is reminiscent of the swimming motions of jellyfish,” wrote the scientists, Leif Ristroph and Stephen Childress of New York University. They suggest the wing motion generates a jet flowing downwards, pushing the machine up, like the domed “bell” jellyfish use to propel themselves. The findings are published in the Journal of the Royal Society Interface. The team came up with the concept through experiments at the University’s Applied Math Lab, concluding that cone- or pyramid-shaped machines might be able to achieve stable hovering by flapping aerodynamic wings with no need for extra “sails” or “tails” that are often needed for stabilization. The machine, made of carbon fiber loops and thin mylar film for the wings, is powered by a tiny motor weighing just 1.1 grams, half as much as a dime. The wings are just 8 cm (3 inches) long. The motor is externally powered, but the team predicts tweaking the wing size would boost lift and allow for an onboard battery. The study is “a step towards a feasible device,” they wrote, suggesting that such small crafts could be used for surveillance, reconnaissance and traffic and air quality monitoring.