David R Brooks wrote:
snip of lots of good stuff
Pneumatics are very hard to use when you want precision of movement.
This is because air is compressible: it's like trying to position
something accurately, when you have to push it through a large spring.
Very difficult.

Using sensors and feedback make pneumatics a whole lot more accurate.
Given that OP is apparently trained as a programmer, I'd think this
would be a good way to go.

See:
http://www.shadow.org.uk/products/airmuscles.shtml

for the air muscles and
http://www.engineeringtalk.com/news/msy/msy100.html

for a little on sensors and feedback with pneumatics in robotic
applications.

--RC