Ultra-precision machining of functional micro/nanostructure arrays

Micro/nanostructure arrays are extensively employed in optics, aerospace, energy, and biomedical applications due to their superior functional properties. Ultra-precision machining technologies have emerged as key enablers for the efficient, accurate, and flexible fabrication of these structures, facilitating their industrial-scale production. This paper provides a comprehensive overview of ultra-precision machining technologies for generating functional micro/nanostructure arrays. Firstly, a metrological analysis of the literature of micro/nanostructure arrays and traditional ultra-precision machining is introduced. Subsequently, various ultra-precision machining technologies, including single-point diamond turning, slow/fast tool servo diamond turning, fly cutting, diamond milling, and ultra-precision grinding/polishing, are systematically reviewed. In addition, field-assisted ultra-precision machining methods, such as ultrasonic vibration-assisted machining, laser-assisted machining, ion implantation-assisted machining, magnetic field-assisted machining, and multi-field assisted machining, are summarized for creating micro/nanostructure arrays on difficult-to-machine material surfaces. Then, the functional applications of micro/nanostructure arrays in numerous fields are discussed in detail, including optical regulation, friction reduction, wettability modification, thermal cooling, and anti-icing. And relationships between structural characteristics and functional performance are elucidated. Finally, the current challenges in ultra-precision machining technology for micro/nanostructure arrays are summarized, as well as the outlook and continuously expanding application fields are also outlined.