New concept and fundamental experiments of a smart pneumatic artificial muscle with a conductive fiber

A McKibben artificial muscle consisting of a rubber tube and a mesh sleeve made from fibers is a promising actuator as an artificial muscle because of its high power, low weight, and flexibility. However, an external pressure sensor or an expensive electro/pneumatic regulator is generally required to control the pneumatic pressure to drive the actuator. A novel smart McKibben-type artificial muscle with a pressure-sensing function has been proposed and developed in this study. One fiber on the sleeve of the actuator is converted from a normal to a conductive material. The applied pressure is estimated by observing the electrical resistance of the conductive fiber. Therefore, the fiber works as both a sensor and an actuator element. The fabrication process of the smart artificial muscle is established in this report, and the basic characteristics are clarified. Moreover, a compact driving control system of the smart artificial muscle, which uses a small rotary pump without external sensors, electro/pneumatic regulator, or valves, is proposed.