The robots were created by scientists at the University of Twente in the Netherlands, and the German University in Cairo, located in Egypt.
Measuring just 322 microns long, each one consists of a silicon support wafer covered in a layer of SU-8, which is a polymer known for its mechanical stability and ease of fabrication. While their tails (or flagella) are left bare, the robots' heads are coated with a layer of cobalt-nickel.
When subjected to an oscillating magnetic field roughly equivalent to that emitted by a decorative fridge magnet, magnetic torque on the head causes it move back and forth. This in turn causes the flagellum to oscillate, propelling the robot forward. By angling the line of the magnetic field, it's possible to steer the MagnetoSperm toward a target.