A Pneumatic Artificial Muscle Manufactured Out of Self-Healing Polymers That Can Repair Macroscopic Damages

Pneumatic muscles are mostly constructed out of flexible membranes and are implemented in a wide range of robotic applications. In these soft materials, perforations are often caused by overpressuring of the muscles and wear. In many cases, this leads to limited numbers of actuation cycles. In this letter, pleated pneumatic artificial muscles were developed, whose membrane is constructed out of self-healing polymer. This allows for the complete healing of microscopic and macroscopic damages through a mild heat treatment. Two prototypes were designed, manufactured, and experimentally characterized. The self-healing was validated by repairing large realistic cuts in the muscle membrane completely. Even when repeatedly damaging and healing the muscles, the mechanical properties were recovered in a reversible and repeatable fashion through the self-healing procedure.