Additive, subtractive and formative manufacturing of glass-based functional micro/nanostructures: A comprehensive review

The ever-increasing demands for miniature integrated optics, mechanics, electronics, and biofluidics have generated great interest in high-performance glass components featuring functional micro/nanostructures. Focusing on micro/nanostructuring of optical glass, many landmark processing techniques have been developed. However, due to notable differences in the capabilities of these techniques, researchers often encounter difficulties in selecting the appropriate glass feedstock or determining the optimal/complementary strategy for achieving a specific production task with desired resolution, accuracy, and efficiency. To shed light on potential solutions, this paper presents a state-of-the-art review that covers subtractive, additive, and formative manufacturing of functional micro/nanostructures using the broadest forms of glass feedstocks (including blocks, powders, and precursors). Initiating with a complete technical classification, the fundamentals, developments, and recent breakthroughs in micro/nanostructuring of glass are comprehensively outlined. Subsequently, the essential features (including spatial resolution, surface finish, accuracy, and efficiency) of the collected glass micro/nanomanufacturing techniques are comparatively evaluated, followed by detailed discussions of their capabilities and current challenges. Finally, future prospects are summarized to highlight potential opportunities and directions in glass micro/nanofabrication. This review will offer a panoramic guideline to the selection and innovation of glass materials and processing strategies for application-oriented precision and efficient manufacturing of diverse glass-based functional micro/nanostructures.