4D printing of polycarbonate ternary composites and the biomimetic folding deployment mechanisms

4D printing of shape-morphing systems have promising application prospects in satellites which are suffering from the complex structure of satellite solar panels, unreliable electric driving systems, and lightweight structural requirements. However, the current investigations of 4D printing are focused on shape memory materials with the lower thermal deformation temperature, which limits their practical applications in the aerospace field. Herein, the polycarbonate (PC) is selected as the base material with a thermal deformation temperature of 150 degrees C, and combining with carbon fiber (CF) and carbon nanotubes (CNTs). The dual percolated PC/CNT/CF ternary composite with "point + line" conductive pathways is fabricated. The material demonstrates superior electrical conductivity and shape memory behavior under a 50 V direct current voltage. The "point + line" conductive pathway exhibits excellent electrical performance without hindering the shape memory performance of PC. The PC-3%CNT-3%CF specimen reaches a temperature of 150 degrees C at both ends within 1 min under a voltage of 50 V. The U-shaped shape memory samples are designed to increase the shape recovery properties, and a series of biomimetic models are also developed to illustrate the shape-morphing properties of 4D printing PC composites. The 20 consecutive cycles of shape memory experiments confirm the reliability of the composites. These findings highlight the broad potential applications of the material in the aerospace field.