Biopolymers and Biocomposites for Additive Manufacturing of Optical Frames

Optical frames are used worldwide to correct visual impairments, protect from UV damage, or simply for fashion purposes. Optical frames are often made of poorly bio-degradable and fossil-based materials, with designs not targeted to everyone´s tastes and requirements. Additive manufacturing processes allow personalisation of optical frames and the use of new sustainable biomaterials to replace fossil-based ones. This comprehensive review combines an extensive survey of the scientific literature, market trends, and information from other relevant sources, analysing the biomaterials currently used in additive manufacturing and identifying biomaterials (biopolymers, natural fibres and natural additives) with the potential to be developed into biocomposites for printing optical frames. Requirements for optical devices were carefully considered, such as standards, regulations and demands for manufacturing materials. By comparing with fossil-based analogues, and by discussing the chemical, physical and mechanical properties of each biomaterial, it was found that combining various materials in bio-composites is promising for achieving the desirable properties for printing optical frames. Advantages of the various techniques of this cutting-edge technology were also analysed and discussed for optical industry applications. This work contributes to identifying a way forward for producing sustainable, customisable and inclusive optical frames on demand, using new biocomposites for ad-ditive manufacturing.