Multi-responsive shape memory polymer printed by fused deposition modeling technique

With the help of three-dimensional (3D) printing technique, complicated and sophisticated structured shape memory polymers (SMPs) devices could be obtained, which have drawn tremendous attention in recent years. However, there is technical limitation for 3D photo-polymerization printing technique to prepare multi-responsive SMP devices. A major problem for this is that functional fillers added to the photo-curing resins disturb or even inhibit their photo polymerization process. Herein, we demonstrated that the fused deposition modeling (FDM) technology seems more promising for fabrication of multi-responsive SMP devices. In this research, SMP devices are printed using a new material, polycyclooctene (PCO), whose application in FDM printing is never reported in the previous work. A universal and facile method, gammaray irradiation, is used to realize the crosslinking of printed structures. The printing quality and thermo-responsive speed of SMPs can be improved by incorporation of highly thermal conductive fillers (hexagonal boron nitride, BN) to PCO; in addition, after the addition of multiwalled carbon nanotubes (MWCNTs), the 3D SMP devices obtained multi-responsive ability owing to the enhanced electrical conduction and light absorption of the composite materials.