Conductive Knit-covered Pneumatic Artificial Muscle (k-PAM) Actuator

The paper presents design, fabrication and characteristics of two kinds of conductive Knit-covered Pneumatic Artificial Muscle (it is called as k-PAM in the paper) actuators, in which two different knits are made by braiding silver-coated (conductive) yarn and spandex (non-conductive) yarn with different stitch methods. The k-PAM is able to measure the change in length of the actuator body according to the applied air pressures as well as the strain due to external force. A complete fabrication method is presented to make the actuator work for higher pressure (≥ 300[kPa]). Since the force generated by the actuator is decoupled from the external force, ultimately, it can be directly used to measure not only the length but also the force. Experimental validations are performed describing the characteristics of two different types of k-PAMs. It is expected that the k-PAM can be used directly for robotic applications in higher pressure condition, while the semi-permanent conductive knit provides the actuator with durability in high repetitive operation environment.