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Airships that «swim» through the atmosphere

Jan 31, 2007 | MANUEL MARTIN

Conventional propeller driven airships have their disadvantages. They are inefficient, and thereby wasteful of energy, and they are noisy too. Empa scientists are looking to solve both these problems by using a technology which is simultaneously very advanced and yet simple in concept – their design lets an airship “swim” through the air like a fish moving through water. That this idea could become reality thanks to the development of electroactive polymers (EAPs) is demonstrated by the first flight trials as well as computer simulations. The EAPs need further development, however, and their reliability and useful lifetime must be improved.


How do EAPs work?

Electro active polymers convert electrical energy directly into mechanical work. An elastic membrane made of polymer material is made to deform by subjecting it to an electric field, and when the voltage is removed the membrane regains its original size and shape. Both sides a polymer film is given a very thin coating of electrically conductive graphite, to which the voltage is applied, the device then acting as a compliant electrical capacitor. The electrostatic forces cause the surfaces of the membrane to draw together, compressing the material and causing its surface area to increase.