Abstract

Such rapid advancement places FDM as a transformative technology in additive manufacturing generally, and particularly into the context of the fabrication of complex geometries using bio-based polymers. However, with such inherent limitations regarding their mechanical and thermal properties, these face significant obstacles that need innovative approaches toward improvement. Surface functionalization is now considered one of the frontline strategies in the advanced improvements of the interfacial properties and durability of biobased polymers within FDM applications and represents opportunities for enhancing material performance. This paper discusses recent advances in surface functionalization methods, including plasma treatment, grafting, and nanocoatings applied to optimize PLA, PHA, and their composites functionality. These techniques tune the surface properties at the molecular level and consequently strengthen adhesion, minimize moisture intake, and enhance thermal stability toward improved mechanical properties and longer operating time for the printed parts. Our findings indicate that incorporating functionalization of the surface in the FDM process overcomes some of the challenges of bio-based polymers and achieves the targets of sustainable manufacturing. The work underlines contemporary methods and shows both their implications and practical effects, thus opening a path to future research and industrial applications in high-performance eco-friendly materials.