Exoskeleton inflatable robotic arm with thin McKibben muscle

To realize an extremely safe robot, an exoskeleton inflatable robotic arm with thin McKibben muscles and simple driving systems installed inside the arm, except for air-supply devices, was designed and manufactured using soft materials. McKibben muscles, which are considerably thin, lightweight, flexible, and can be mass produced, are suitable for this soft robotic mechanism. The arm is safe and useful for human-friendly robots owing to its softness, low weight, and compliance. The exoskeleton inflatable robotic arm was modeled, theoretical equations were derived for the joint angle and torque, and theoretical and experimental results obtained at various structural stiffness were compared. In the experiments, the developed arm could bend at 90° and 91° on each side. Furthermore, it was proposed that experimental values can be estimated using theoretical expressions with correction factors.