Direct synthesis of graphene on 3D-printed arbitrary shaped CoCrMo alloy substrates using double-tube chemical vapor deposition

Graphene has garnered significant attention owing to its remarkable properties, making it highly suitable for biomedical applications that require biocompatible, functional interfaces. This research examines the direct synthesis of graphene on a cobalt-chromium-molybdenum (CoCrMo) alloy utilizing an enhanced double-tube chemical vapor deposition (DT-CVD) process to form a conformal graphene interfacial layer on CoCrMo with potential relevance to protective and biomedically relevant surface engineering. The CoCrMo alloy was produced by additive manufacturing (3D printing) via direct metal laser sintering (DMLS), facilitating the assessment of components with multiaxial curvature and recessed features. The growth mechanism of graphene on CoCrMo is comprehensively examined, with emphasis on the influence of the DT-CVD method on microstructure and surface morphology. A range of spectroscopic and microscopic techniques confirmed the integrity, crystallinity, and uniformity of the graphene synthesized on CoCrMo substrates. Ultrasonication studies demonstrated strong adherence of graphene films to the alloy surface, affirming its reliability in biomedical environments. Contact-angle measurements on as-grown graphene on CoCrMo substrates indicate enhanced hydrophobicity, a surface characteristic desirable across many biomedical applications. The results show that the DT-CVD technique enables efficient, homogeneous, and conformal graphene growth on CoCrMo substrates with different geometries and surface curvatures, demonstrating its adaptability. This study presents, for the first time, a straightforward method for achieving continuous, stable graphene growth on biomedically significant CoCrMo alloy substrates, which could potentially enhance their suitability for next-generation implantable devices and engineered biomedical interfaces. We employed direct DT-CVD synthesis to grow conformal graphene on 3D-printed CoCrMo alloy on flat and arbitrary geometries. Produced uniform graphene exhibited high crystallinity, strong adhesion to the CoCrMo substrate, and near super-hydrophobic surface properties. A short-term stability in biomedically relevant physiological solution was tested, indicating a pathway for potential future biomedical applications associated with additively manufactured metallic devices and platforms.