A team of researchers at the University of Twente in the Netherlands and German University in Cairo, Egypt, has developed tiny robots that resemble sperm and are controlled by oscillating, weak magnetic fields.

The tasks they are designed to perform are actually far from tiny. The discovery is promising for the future of in-vitro fertilization, cell sorting, drug delivery and the cleaning of clogged arteries.

At 322 microns long, they are significantly bigger than mammalian sperm, which measure a measly 55 microns by comparison.

The head is coated in cobalt-nickel, which reacts with force upon exposure to a magnetic field approximately the same strength as that of a refrigerator magnet.

This magnetic torque in the head causes the uncoated tail to swish back and forth, propelling the 'brobot' onwards.

Designers hope to create even smaller versions of the robot in the future. Plans are underway for a nano-sized magnetic flagellum that will improve swimming efficiency.

Despite the catchy nickname, it is officially referred to as the MagnetoSperm microrobot.

"Nature has designed efficient tools for locomotion at micro-scales," says principal study investigator and associate professor at the University of Twente, Dr. Sarthak Misra. "Our microrobots are either inspired from nature or directly use living micro-organisms such as magnetotactic bacteria and sperm cells for complex micro-manipulation and targeted therapy tasks."

Misra designed the MagnetoSperm along with Islam Khalil and colleagues at MIRA-Institute for Biomedical Technology and Technical Medicine at the University of Twente.

A report on their discovery was published in the journal Applied Physics Letters.