Water-surface vortices drive tiny rotors without electricity, magnets or chemicals

Reliably generating controlled miniature rotations has long been a challenge: Chemical propulsion systems wear out, and methods that use electric or magnetic fields require complex setups. A team from KIT's Institute of Microstructure Technology (IMT) and the Suzhou Institute of Nano-tech and Nano-bionics (SINANO) at the Chinese Academy of Sciences has now demonstrated that flow at a water surface alone is sufficient to rotate a floating object in a fixed direction. Their research is published in the journal Science Advances.