Green ink revolution: Pioneering eco-friendly 3D printing with vegetable oil-derived inks

Sustainability in additive manufacturing (AM) (3D printing) could play a pivotal role for manufacturers and producers in the next-generation manufacturing framework. The market for 3D printing is expanding rapidly, and it is expected to do so in the foreseeable years to come. As ecologically, responsible manufacturing gains more attention, renewable substitutes for regular commercial 3D printable inks must be developed for lower environmental carbon footprints (less CO2 emissions, recycling, bio-compatibility, and zero waste). Herein, we review the recent literature on using vegetable oil (VO) as bio-based inks for sustainable formulations for digital light processing or stereolithography additive printing. The feedstock selections (VO, terpenes, and waste cooking oil), and the chemistry of the VO-based synthons toward sustainability in the field of photopolymerization-based 3D printing are discussed. These renewable materials can mitigate the detrimental environmental effects of AM while remaining competitive with the existing fossil-based resins produced by industrial manufacturers. The current challenges and limitations of AM in terms of surface finish, material properties, photo-curing time, and end-of-use recycling options from biomass-derived photocurable monomers are also identified. Overall, this development promotes the bio-based economy and allows for the on-demand production of a variety of sustainable inks for AM and sustainable end-of-use products.