Novel 4D-printing pellets with infrared-light responsive shape memory effect

Four-dimensional (4D)-printing technology is attractive to researchers since it combines 3D printing with smart materials to produce 3D structures with various shapes and change shapes under specific external stimuli. Herein, novel shape memory polymer (SMP) pellets with infrared-light responsive shape memory effect were developed for 4D printing applications. The structures, properties, and infrared-light responsive shape memory performances of the resulting (SMP) pellets were thoroughly investigated. The results showed PDA/SMP pellets prepared by direct loading of polydopamine (PDA) particles on SMP pellets displayed less influence on the basic properties of SMP while fluidity was enhanced. The obtained PDA/SMP pellets employed as feed materials for particle 3D printers revealed good thermal-induced shape memory performance and photo-responsive shape memory performance in printed 3D structures. Under infrared-light irradiation, the curled shape recovered to straight splines within 60 s due to the strong absorption and good photo-thermal conversion of the loaded PDA nanoparticles under infrared light. Overall, the as-prepared PDA/SMP pellets look promising for use in biomedical fields and smart devices, as well as remote control deformation with 4D printing technology.