Laser-Based Micro/Nano Additive Manufacturing of Conductive Structures on Transparent Substrates: Technical Approaches, Challenges, and Future Prospects

Additive manufacturing (AM) addresses the challenges faced by traditional manufacturing techniques in terms of cost, time and machinability. It is gradually advancing toward higher precision and smaller sizes, particularly at the micrometer scale where the limits are much tighter than in macro manufacturing. Laser microadditive manufacturing (LMAM) offers unmatched high precision and flexibility compared to macroscopic AM methods (up to tens of micrometers). Therefore, LMAM technologies have shown great potential in the manufacturing of customized, miniaturized components and high-performance materials. They have broad application prospects in aerospace, medical devices, electronic components, mold manufacturing and microelectromechanical systems (MEMS). However, there is currently no established LMAM solution for conductive microstructures at small scales. To address the issues related to finite resolution and conductivity of transparent substrate surfaces, various new LMAM technologies are being developed for micrometer/nanometer scale conductive structures. This paper reviews the efforts made so far with a focus on laser additive manufacturing (LAM), laser-induced transfer (LIT), laser-induced chemical deposition (LICD), and laser electrochemical composite deposition (LECD) technologies. Importantly, this paper provides a detailed analysis of LMAM technologies and their unique implications while comparing the potential of current LMAM technologies for conductive microstructures. Finally, it discusses improvement measures in the LMAM process and suggests future research work.