Using a magnetic field no stronger than a fridge magnet, the team made the robot "swim" forward and steered it towards a fixed point. In a new study, published today (June 2) in the journal Applied Physics Letters, the researchers created 322 1-micron-long (about 10 times the width of a human hair) robots with heads thickly coated with cobalt-nickel, but uncoated tails. "We have built a biologically inspired micro-robot that looks like a sperm cell but is completely fabricated in the lab," said Dr Sarthak Misra, a robotics engineer at the University of Twente in the Netherlands. The new gadget is made from a strong but flexible polymer, with a metal layer painted onto its head using a technique called electron beam evaporation. The magnetic swimmers could be used for a number of biomedical applications, including drug administration, in vitro fertilization and the cleaning of clogged arteries, the researchers said. [The 6 Strangest Robots Ever Created] 
 
 Improvements in technology are making many products smaller, but it is difficult to assemble objects on the nanoscale (a billionth of a meter) or microscale (a millionth of a meter), the researchers said.
– Technophobes may be alarmed to learn that new sperm-like robots could soon be performing many activities—including fertilizing human eggs. Researchers say the tiny bots, dubbed "MagnetoSperm," were inspired by the shape and movement of sperm cells and can "swim" to their target with incredible accuracy, LiveScience reports. They believe the sperm bots could be useful in nanomanufacturing as well as for medical uses including unclogging arteries, drug administration, and in vitro fertilization. The robots have a metal head and a body of flexible polymer, and are steered through a field produced by electromagnetic coils. "The magnetic head is used to orient it in a certain direction and then, just by flapping its tail, it starts to move forward," the lead researcher explains to the BBC. "The flapping happens because we change the current in the coils," he says, predicting that the tiny bots will prove useful where it is necessary to reach "precise locations." The bots are still a lot slower—and around six times bigger—than human sperm, but the MagnetoSperm team says it is working on creating smaller, faster versions. (Meanwhile, scientists have recently found the world's oldest sperm.)