Programming the deformation of the temperature driven spiral structure in 4D printing

Achieving shape programming of 4D printed actuators by varying the manufacturing process parameters. In this study, the effect of different path combinations on structural deformation was investigated. By altering the driving layer, passive layer, and grid angle, the spiral deformation direction of the double-layer structure was precisely controlled. Additionally, a finite element analysis model was established to predict the deformation behavior of PLA-based spiral structures. Furthermore, the influence of printing speed, nozzle temperature, line width, layer height, and plate temperature on the spiral curvature of the structure was examined. The results show that increasing printing speed and plate temperature can improve the spiral behavior of the structure, whereas increasing line width, layer height, and nozzle temperature have opposite effects. A multiple linear regression analysis was conducted on the five printing parameters to predict their influence on the spiral curvature of the structure, and a predictive model for the spiral deformation was developed. The structure was partitioned for design purposes, aiming to achieve diverse deformations of the actuator under the same geometric configuration. A loop-shaped actuator was designed to capture objects. The results showed that the path combination determined the spiral direction of the actuator, while the forming parameters effectively controlled the spiral curvature of the actuator.