Multi‐Responsive Artificial Muscle Based on Robust and Conductive Coaxial MXene Fibers

ABSTRACT The burgeoning field of robotics has intensified the demand for advanced flexible actuators with intelligent responsiveness. However, the development of fiber‐shaped artificial muscles capable of reversible bidirectional actuation under multiple stimuli remains a challenge. Herein, we report the continuous fabrication of robust and conductive MXene fibers with oriented surface wrinkles via coaxial wet‐spinning. In this design, carboxymethyl chitosan (CMCS) blended with sodium alginate (SA) serves as the core matrix, while MXene nanosheets constitute the conductive and light‐absorbing shell. Zn 2+ ions act as cross‐linkers in the coagulation bath, reinforcing the interfacial interactions between polymer chains and MXene nanosheets. The CMCS‐SA double‐network significantly enhances both the formation of fibers and their final mechanical properties. The optimized fibers exhibit a tensile stress of up to 231.8 MPa, an elongation at break of 6.2%, and a conductivity of 83.9 S cm −1 . Benefiting from the photothermal and Joule heating effects of MXene and the hygroscopicity of the CMCS‐SA, the coiled artificial muscle fibers demonstrate bidirectional actuation in response to near‐infrared light, direct current electricity, and moisture. Furthermore, these muscle fibers show great potential for applications in textiles, prosthetic arms, and surgical sutures, exhibiting remarkable responsiveness to external stimuli.