3D‐Laminated Graphene with Combined Laser Irradiation and Resin Infiltration toward Designable Macrostructure and Multifunction

Macroscopic 3D graphene has become a significant topic for satisfying the continuously upgraded smart structures and devices. Compared with liquid assembling and catalytic templating methods, laser‐induced graphene (LIG) is showing facile and scalable advantages but still faces limited sizes and geometries by using template induction or on‐site lay‐up strategies. In this work, a new LIG protocol is developed for facile stacking and shaping 3D LIG macrostructures by laminating layers of LIG papers (LIGPs) with combined resin infiltration and hot pressing. Specifically, the constructed 3D LIGP composites (LIGP‐C) are compatible with large area, high thickness, and customizable flat or curved shapes. Additionally, systematic research is explored for investigating critical processing parameters on tuning its multifunctional properties. As the laminated layers are stacked from 1 to 10, it is discovered that piezoresistivity (i.e., gauge factor) of LIGP‐C dramatically reflects an ≈3900% improvement from 0.39 to 15.7 while mechanical and electrical properties maintain simultaneously at the highest levels, attributed to the formation of densely packed fusion layers. Along with excellent durability for resisting multiple harsh environments, a sensor‐array system with 5 × 5 LIGP‐C elements is finally demonstrated on fiber‐reinforced polymeric composites for accurate strain mapping.