Advances in precision micro/nano-electroforming: a state-of-the-art review

Micro/nano-electroforming has received considerable interest from various industry sectors as an advanced micro-manufacturing technique that offers high dimensional precision and replication accuracy. When tight feature tolerances and miniaturized geometries are required, electroforming provides unique advantages and cost-effective characteristics for fabrication. This paper firstly reviews the historical development of micro-electroforming, particularly within the past two decades. The fundamentals of electroforming and relevant applications are firstly discussed, and the common requirements are then proposed. Based on these requirements, we have focused on the processes of micro-electroforming from the ultraviolet lithography, electroplating, and moulding process to electroforming process characterization and optimization, bath compositions, agitation, and some hybrid processes. Progress from electrochemical micro/nano-manufacturing processes, such as 3D printing by electrodeposition and electrochemical wet stamping, is also included. The eventual nanocomposite electroforming is highlighted from the perspectives of the formation mechanism, deposition properties and relevant applications. Finally, a conclusion and future perspectives are presented. This review will demonstrate how the micro/nano-electroforming process can be further developed to meet the requirements of new product development from precision optics, micro/nano-moulding, high-performance coatings and future micro/nano-manufacturing.