Metallic rods about 500 times smaller than the width of a human hair have been turned into tiny “propellers” by a Canadian research team.

The “nanorods” spin after becoming anchored to silicon wafers, Chemical Communications has reported.

Their motion is driven by addition of hydrogen peroxide (H2O2) to the solution in which they are contained.

A reaction at the free ends liberates gas bubbles to provide thrust, turning the rods at a near constant speed.

Only when the supply of hydrogen peroxide fuel is exhausted do the rods stop spinning.

Geoffrey Ozin and colleagues at the University of Toronto used nanorods made up of a gold segment and a smaller nickel segment.

The rods attach to silicon wafers at the gold end. This metal does not react with hydrogen peroxide.

Nickel, on the other hand, acts as a catalyst in a “decomposition” reaction that produces oxygen and water from H2O2.

As oxygen bubbles off the nickel surface, it provides gas propulsion for the nanorods. The rods’ behaviour was discovered entirely by accident.

More here.