Robotics/Exotic Robots/Special Robot Brains
Most robots have an electronic "brain" (part that uses sensor input to determine actuator output). This can be either a simple electronic circuit, a µcontroller or a PC. This is not the only way to build a robot "brain".
Mechanical Robot Brains
One of the first robots was designed by Da Vinci, this was a small vehicle powered by wind-up springs and it was "programed" by changing gears. Although possible this kind of robot brains are very hard to design and build.
Pneumatic Robot Brains
If you need to automate some part of a plant where explosive gases are used it might be too dangerous to use electronic circuits. Instead pneumatic circuits are used. It's possible to construct logical circuits, timers, sequences,... using pneumatic valves and cylinders. You can find a lot of pneumatic valves for automation here: www.ngtvalves.com