Recent Advances in 3D Printing of Two-Dimensional Materials and Devices

Two-dimensional (2D) materials offer opportunities for constructing functional devices; however, integrating them into macroscopic structures requires precise control over nanosheet dispersion, processing parameters, and structural design. This review summarizes research on the fabrication of 3D structures using nanosheet-based inks and composite feedstocks-including graphene and its derivatives, MXenes, transition metal dichalcogenides, hexagonal boron nitride, and black phosphorus. Studies indicate that material performance is determined by the combined effects of feedstock composition, printing conditions, structural design, and post-processing techniques. Direct Ink Writing (DIW) is a particularly suitable fabrication technique for various porous lattices and self-supporting structures where nanosheets form the primary functional network. High-concentration aqueous MXene inks and rheologically tuned graphene oxide-based inks serve as typical feedstocks, provided they exhibit favorable shear-thinning behavior, shape retention, and structural recovery capabilities. Regarding polymer-based composite components, Fused Deposition Modeling (FDM) is applicable to thermoplastic feedstocks loaded with 2D materials, whereas Stereolithography (SLA) and Digital Light Processing (DLP) utilize nanosheet-loaded photocurable resins to fabricate composites with intricate features, albeit with applications constrained by light attenuation and curing characteristics. Applications in sensing, energy storage devices, and biomedical scaffolds demonstrate the immense potential of these methods, while printed optoelectronic devices are discussed as a complementary case of device integration. Nevertheless, challenges such as material instability, trade-offs between resolution and scale, post-processing shrinkage, and incomplete biosafety assessments remain significant barriers to practical application, highlighting the need to develop reproducible processing techniques and conduct validation studies focused on real-world use.