Oliver Schmidt's team at the Institute for Integrative Nanosciences in Germany has created a controllable spermbot. Not a word we'd ever think we'd be writing either. After adding cone-shaped nanotubes to bull sperm, Schmidt's team observed that when one swam into the wider end of the tube, it would become trapped, but with the flagella free, enabling it to carry on swimming. Next, the team added magnetic fields into (or rather, near) the mix, and was able to control the direction in which the spermbots moved. It's not a stretch to imagine obvious applications in fertility, but it could go beyond that. Schmidt believes that sperm cells could be used for "robotic micro-systems," as they are harmless to the body, and come with their own power source. Micro-robots were always destined to be a part of our future, but we're betting no one had their money on this.