McKibben Artificial Muscle Embedded with Stretchable Textile Sensor

Abstract

In order to control the posture of soft robots in dynamic environments, the movement of soft actuators such as McKibben artificial muscles must be monitored in real time. Researchers have developed various McKibben artificial muscles with embedded sensing components to achieve such monitoring. However, incorporating sensors into McKibben artificial muscles makes the system configuration more complicated and reduces the actuator's contraction rate. Furthermore, complex processing and circuitry are required, which limits applications. This study introduces a thin McKibben artificial muscle with an embedded resistive stretchable textile sensor (TES‐MAM), which does not require specialized measuring instruments. TES‐MAM measures displacement without additional sensing components outside the thin McKibben artificial muscle by incorporating a stretchable textile sensor inside the McKibben artificial muscle. The textile sensor exhibits excellent stretchability and does not degrade the contraction ratio. By fully embedding the textile sensor within the McKibben artificial muscle, which has an outer diameter of 4.5 mm, the structure of McKibben artificial muscle remains compact. TES‐MAM provides a clear and stable resistance response during repeated pressurization and release cycles under various displacement inputs. Using TES‐MAM, a single‐degree‐of‐freedom robotic arm is constructed and its ability to measure joint posture in real time is successfully demonstrated.