Review on 3D-printed graphene-reinforced composites for structural applications

The reasonable macro-micro structural design presents a significant impact on the mechanical properties of structural composites, and the progress of three-dimensional (3D) printing provides an opportunity for efficient and controllable construction of multi-dimensional lightweight and high-strength composites. Recently, carbon -based nanomaterials are in the spotlight as nanofillers of structural composites for the huge available specific surface area and excellent mechanical properties, especially graphene, the unique two-dimensional (2D) nano -sheet with superior Young's modulus, intrinsic strength, and significantly outstanding stretchability. For the application of graphene in 3D printing, the macro-assembly can fabricate complex 3D objects with any size and configuration, while realizing the highly oriented distribution and the construction of a penetrating structural network by micro-regulation. Herein, the multiscale structural composites reinforced by 3D-printed graphene are outlined, including ceramic matrix composites, polymer matrix composites, and metal matrix composites. Moreover, the current challenges and future application prospects in this fast-growing field are predicted.