Liquid crystalline 3D printing for superstrong graphene microlattices with high density

Abstract

Processing solvated graphene by ink printing technique holds exciting prospective in fabricating macroscopic carbonaceous materials with designed structures and outstanding properties. Direct ink writing has been utilized for highly porous graphene aerogels for multifunctional uses. However, densified graphene solid materials have kept unreached by 3D printing for the conflict between high concentration and good homogeneousness of printing ink. Here, we have fabricated high density compact graphene microlattices (CGM) with ordered structure via liquid crystalline (LC) direct ink writing. Concentrated but homogeneous graphene oxide/glycerol inks were prepared, reaching a solid containing up to ∼6 wt% and possessing LC nature. The flow unified LC order of inks renders highly ordered micro-structure of CGM, outstanding compressive strength (62.7 MPa at 90% strain) and high electrical conductivity of 2073 S m−1. Our CGM also exhibit an impressive elasticity up to 15–18% strain. Our facile methodology has introduced a graphene solid architecture material with high mechanical properties and multi functionalities, which should become a useful engineered carbon scaffolds with designed multiscale structures, mechanical and functional properties.