3D Printing of Continuous Helical Carbon Fiber Reinforced Polylactic Acid Composites, Exhibiting Integrated Mechanical, Actuating, and Sensing Multifunctional Synergistic Properties

Abstract The integration of actuation and sensing functions in smart actuating materials has been a key challenge in their development. Inspired by the silk‐spinning, self‐twisting, and cocoon‐forming processes of silkworms, this study proposes a novel design and 3D printing manufacturing method for continuous helical twisted carbon fiber reinforced polylactic acid (CHTCFP) composites, achieving an integrated design that successfully combines excellent mechanical properties, superior actuation capabilities, and real‐time precise sensing functions. Through the helical twisting of carbon fibers, the tensile strength increases by 53.2%, the flexural strength by 41.6%, the electrical conductivity by 152%, and the thermal conductivity by 96.3% compared to traditional continuous carbon fiber reinforced polylactic acid composites. Additionally, the 3D printed specimens rapidly respond to external stimuli through electromechanical activation of shape‐memory deformation, achieving a shape‐memory recovery rate of up to 99.02%. These specimens also maintain real‐time stable sensing characteristics under 5000 cycles of tensile loading, enabling precise and real‐time monitoring of stress and deformation angles during the actuation process. To demonstrate the multifunctionality of the CHTCFP composites, an integrated actuation‐sensing satellite solar sail deployment mechanism and a lunar lander antenna folding mechanism are constructed, broadening their application potential in practical engineering.