By Stuart Fox | PopSci.com

While so many scientists spend their time trying to create nanobots the size of bacteria, researcher at the NanoRobotics Laboratory of the École Polytechnique de Montréal, Canada, decided to simply take direct control of live bacteria. By using a computer-controlled magnetic field, the researchers turned the bacteria into fully-compliant biological nanorobots.
The trick was using a type of microbe known as magnetotactic bacteria.

These critters have little internal compasses, and will follow the pull of a magnetic field. By manipulating a magnetic field, the researchers tricked the bacteria into forming a giant, computer-controlled swarm. In one experiment, the researchers had the bacterial swarm assemble a small pyramid. In another, they directed bacteria through the blood stream of a rat, like in Innerspace.

If you’re wondering which ancient pyramid inspired the researchers -- and is shown in the video on the left bottom corner -- it’s the Djoser step pyramid, in Egypt, which the researcher note was "an important, initial milestone in the history of man-made structures."
Images and video: NanoRobotics Laboratory, École Polytechnique de Montréal