Researchers have developed a way to handle small objects in three dimensions using magnetic levitation, even when the objects themselves are not magnetic.

George Whitesides and his team at Harvard University in Cambridge, Massachusetts, suspended a non-magnetic nylon screw in a liquid that becomes magnetic when exposed to magnets. The authors placed one magnet above the container and one below, which made the fluid shift towards the magnets, leaving the screw suspended in the middle.

When the apparatus is rotated, the object rotates with it. Moving an extra magnet around the outside of the device further shifts the liquid and the screw's orientation.

The technique could be useful on assembly lines, allowing the manipulation of materials that are too fragile or soft to be handled by other equipment.

Proc. Natl Acad. Sci. USA http://doi.org/vgq (2014)