Researchers at IFW Dresden built "spermbots": tiny metal-coated polymer helices that wrap around the tail of a sperm cell. A rotating magnetic field drives each helix, so the cell can be captured, steered to an egg and released. The idea is to help healthy sperm that swim poorly, though it is still far from clinical use.
via 'Spermbots' could help women trying to conceive | Phys.org