Look at this video of a Turing Machine built with the LEGO Mindstorm platform:
This is a part of a project at computer science of Aarhus University in Denmark. At this page you can find the official blog of the project where you can follow the step-by-step development of the robotic Turing Machine.
Turing Machines were described by Alan Mathinson Turing in 1936: they are a simple way to describe the logic of any computer algorithm. Despite their simplicity they are useful to describe and understand the limits of mechanical computation.
A Turing Machine consists in:
- a tape arbitrarily expandable to the left and to the right, divided into adiacent cell containg a symbol;
- a head wich can move in any direction over the tape and can read and/or write symbols on it;
- a set of transition functions that describe how the machine operates;
- a state wich describes the current status of the machine.
For more information about the Turing Machine you can visit this page on Wikipedia.