Skeletal Muscle Fibers Inspired Polymeric Actuator by Assembly of Triblock Polymers

Abstract Inspired by the striated structure of skeletal muscle fibers, a polymeric actuator by assembling two symmetric triblock copolymers, namely, polystyrene‐ b ‐poly(acrylic acid)‐ b ‐polystyrene (SAS) and polystyrene‐ b ‐poly(ethylene oxide)‐ b ‐polystyrene (SES) is developed. Owing to the microphase separation of the triblock copolymers and hydrogen‐bonding complexation of their middle segments, the SAS/SES assembly forms a lamellar structure with alternating vitrified S and hydrogen‐bonded A/E association layers. The SAS/SES strip can be actuated and operate in response to environmental pH. The contraction ratio and working density of the SAS/SES actuator are approximately 50% and 90 kJ m −3 , respectively; these values are higher than those of skeletal muscle fibers. In addition, the SAS/SES actuator shows a “catch‐state”, that is, it can maintain force without energy consumption, which is a feature of mollusc muscle but not skeletal muscle. This study provides a biomimetic approach for the development of artificial polymeric actuators with outstanding performance.