An American inventor has requested a patent on a 'flying saucer' powered by ionised plasma and helium.

Subrata Roy, an aerospace engineer at the University of Florida, has filed the patent for a Wingless Hovering Micro Air Vehicle.

The vehicle is only 15cm wide and will not be leaving the atmosphere, but the design nevertheless looks feasible.

The saucer is filled with helium to offset the weight of batteries and an electric motor which ionises the air around the rim of the craft into plasma, which is then circulated around the craft to generate lift.

"The wingless design of specific embodiments can allow operation with no rotating or moving components," according to the filing.

"Additional embodiments can allow active response to the surrounding flow conditions.

"The issue of low lift to drag ratio and degradation of airfoil efficiency due to the inability of laminar boundary layers attachment can also be significantly reduced, or eliminated."

Roy claimed that the device could operate in relatively high winds and carry a payload.