The robot at the bottom of this image is controlled in part by a slime mould called Physarum polycephalum that avoids light. Developed by researchers at the University of Southampton and Kobe University, the robot leverages the mold's love of dark, humid, moist environments. From New Scientist:
They grew slime in a six-pointed star shape on top of a circuit and connected it remotely, via a computer, to the hexapod bot. Any light shone on sensors mounted on top of the robot were used to control light shone onto one of the six points of the circuit-mounted mould – each corresponding to a leg of the bot.Link (Thanks, Dave Gill!)
As the slime tried to get away from the light its movement was sensed by the circuit and used to control one of the robot's six legs. The robot then scrabbled away from bright lights as a mechanical embodiment of the mould. Eventually, this type of control could be incorporated into the bot itself rather than used remotely.
(University of Southampton researcher Klaus-Peter) Zauner believes engineers will need to look towards this type of simple control mechanism, especially as components are scaled down. "On the nanoscale, we have to learn how to work with autonomous components," he says. "We have to let molecules do what they naturally do."