Scientists at the Institute for Integrative Nanosciences in Dresden, Germany, have created "the first sperm-based biobots"—a cybernetic microorganism made of metal and a bull's sperm cell that can be remote controlled and used to impregnate an egg or deliver a drug to a target anywhere inside your body.
The spermbot was created using a 50-micron-long microtube, which was used to capture the sperm cell, leaving its flagellum—the tail that propels the sperm—outside. Then they used a magnetic field to control the direction of the metal tube, pointing the sperm into any the bearing they wanted.
According to the research leader, Oliver Schmidt, "sperm cells are an attractive option because they are harmless to the human body, do not require an external power source, and can swim through viscous liquids." Sounds gross, but it's quite clever.