Pneumatic Artificial Muscles
Pneumatic artificial muscles are contractile or extensional apparatus that are being operated by pressurized air in a pneumatic bladder. PAMs are very light in weight because of their thin membranes. This allows them to be directly linked to the structure they power, which is an added advantage when considering the replacement of a muscle. If defective muscles have to be substituted, its location will always be known and its replacement becomes much easier. This is a vital characteristic, since the membrane is connected to rigid endpoints, which enables tension concentrations and therefore possible membrane ruptures. One of the important advantage of PAMs is their compliant behaviour, when force gets exerted on the PAM, it "gives in", without increasing the force in the actuation. This is an important feature when the PAM is used as an actuator in a robot that interacts with a human, or when sensitive operations have to be carried out.