In the course of researching air actuators for my Lego J5 robot, I found Air Muscles. Simple compressed air powered devices that are capable of lifting more than 400 times their own weight.
This newsletter from CLAWAR (www.clawar.com) is a good primer for understanding air muscles.
Special Section Support Technologies for CLAWAR Machines and other mobile robots
Follow up with this article, giving comparisons to human muscles.
Put it all together and you get this!
Arm and Hand by The Shadow Robot Project
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