Manufacturing of shape memory composite hinges by additive manufacturing

Shape memory polymer composites (SMPCs) are smart materials that merge the structural performances of carbon fibers with the functional behavior of shape memory polymers. SMPC laminates were manufactured using manual lamination and compression molding, resulting in a size of 30x100 mm2. Three carbon fiber reinforced (CFR) plies and two shape memory polymer (SMP) interlayers deposited between CFR plies were used. Ten thermo-mechanical cycles were performed, and shape memory (SM) performances were gathered from the tests. The tested laminate exhibited average shape fixity ratios of 50% across all cycles, while shape recovery ratios were higher than 95%. Moreover, an average actuation load of 10 N was also measured. Finally, the SMPC laminate was paired with polymeric support working as a hinge produced by FDM, and actuation tests were carried out. In this way the effective operation of the system was demonstrated. An applied 180° folded configuration was nearly fully recovered in approximately 3 minutes.