http://www.robotgroup.net/mark/Centipede_concept.gif

The Centipeded is a segmented insect-like robot. The segments are constructed such that they are removable and "stackable". That is, the robot can be made almost any length you like.

I have been encountering some problems in the design definition stage. The big problem is that of knowing the turn angle. I would like to use a pot for it but all the ones I have looked at have a high friction on the wiper. The robot is light weight so this is unacceptable. If you know of a small, low-friction potentiometer, please drop me a line.

Failing that I have decided that a flex sensor (http://www.spectrasymbol.com/bend.html) would be a good choice. They only sense flexing in one direction so I would need two of them back to back. I figure they would have to be about one inch long.