Harvard University researchers have developed remote-controlled nano-devices that mimic the corkscrew motion of flagella and that may one day deliver drugs to where they are needed in the body.

The devices have a spherical head 200 to 300 nanometers across and a corkscrew-shaped tail 1 to 2 microns long. They are coated with cobalt, allowing an external magnetic field to make the propellers corkscrew through water at up to 40 microns per second.