Biologically inspired damage tolerance in braided pneumatic muscle actuators

As the operation of robotic systems moves away from solely manufacturing environments to arenas where they must operate alongside humans, so the essential characteristics of their design has transformed. A move from traditional robot designs to more inherently safe concepts is required. Studying biological systems to determine how they achieve safe interactions is one approach being used. This then seeks to mimic the ingredients that make this interaction safe in robotics systems. This is often achieved through softness both in terms of a soft fleshy external covering and through motor systems that introduce joint compliance for softer physical Human-Robot Interaction (pHRI). This has led to the development of new actuators with performance characteristics that at least on a macroscopic level try to emulate the function of organic muscle. One of the most promising among these is the pneumatic Muscle Actuator (pMA). However, as with organic muscle, these soft actuators are more susceptible to damage than many traditional actuators. Whilst organic muscle can regenerate and recover, artificial systems do not possess this ability. This article analyzes how organic muscle is able to operate even after extreme trauma and shows how functionally similar techniques can be used with pMAs.