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