Comparison of static force exerted by fluidic muscle and shadow air muscle

Many researchers have investigated different properties and behaviour of pneumatic muscles actuators (PMAs). Most of them have dealt with the force-contraction (force-relative displacement) characteristics or control of PMAs. In this paper two different type PMAs are compared: Fluidic Muscle made by Festo Company and Shadow Air Muscle made by Shadow Robot Company. The most relevant difference between them can be noticed in their structure. The Fluidic Muscle is an embedded muscle which means the load carrying element is embedded in its membrane, while Shadow Air Muscle is a netted muscle, but in its non-loaded condition there is a gap between the membrane and the load carrying element. Among other things, force developed by pneumatic muscle actuators depends on applied pressure, contraction, geometry and the used materials. As it is described in this paper, they show significantly different force-contraction characteristics despite having similar dimensional properties. These characteristics are determined by experimental measurement.