High-Temperature-Tolerant Artificial Muscles Using Poly(p-phenylene benzobisoxazole) Composite Yarns

Today the developed yarn muscles or actuators still cannot satisfy the requirements of working in high-temperature environments. Thermal resistivity is highly needed in aerospace and industrial protection applications. Herein, an artificial muscle with high-temperature tolerance is prepared using carbon nanotube (CNT) wrapped poly (p-phenylene benzobisoxazole) (PBO) composite yarns. A thermal twisting method was utilized to reorientate the stiff PBO molecular chains into a uniform and twist-stable coiled structure. The CNT/PBO composite yarn muscle generates reversible contractile strokes up to 18.9% under 5.4 MPa tension and outputs 1.3 kJ kg(-1) energy density. In contrast to previous actuators, which are normally operated at room temperatures, the CNT/PBO composite yarn muscles can work at ambient temperatures up to 300 degrees C with high contractile stroke and long-term stability. A bionic inchworm robot, a deployable structure, and smart textiles driven by the high-temperature-tolerant yarn muscles were demonstrated, showing the promise as a soft actuator towards high-temperature environment applications.