A comprehensive review on additive manufacturing of glass: Recent progress and future outlook

As an advanced and revolutionary technology, additive manufacturing (AM) has received significant research attention in the field of materials processing. It is also gradually being applied to glass manufacturing owing to its significant advantages of being able to fabricate glass components with arbitrary and complex geometry. In addition, it ensures a high spatial resolution, low surface roughness (without polishing treatment), high optical transparency, and guarantees accuracy in terms of small-scale characteristics. Whilst the development of AM technology in glass manufacturing is relatively slower than in polymer, metal, and ceramics manufacturing, it has made considerable progress in the fabrication of functional glass devices, including gradient refractive index optics, microlenses, colour converters, microfluidics, and micro-toroid optical resonators. Great potential has been exhibited on multi-material, multi-scale, multi-functionality (M3), and hybrid additive manufacturing, it will definitely be the future trend on transparent glass components fabrication. This review provides a systematic summary of different AM techniques, with an emphasis on the printing strategies, resolution, multi-material capability, and property evaluation of glass. In addition, the defect formation, feasible solutions, and potentially suitable applications are discussed. An in-depth analysis of the current limitations and perspectives on the future developments of each category of AM are also provided.