Frontiers of Laser-Based 3D Printing: A Perspective on Multi-Photon Lithography

Lasers are instrumental in enabling precise processing and fostering the development of new technologies. Particularly, ultrafast lasers, due to their unique interaction with matter, can achieve not only exceptional spatial precision but also meticulously determine the degree of modification. A prime example of this is laser-based 3D printing through multi-photon lithography (MPL). This approach remarkably enables the printing of true 3D structures at the micro- and nanoscale, without the need for masks or cumbersome tools, simply by using computer-aided designs. Owing to these unique capabilities, MPL has emerged as a powerful manufacturing technique across various multidisciplinary fields. The ongoing growth in MPL's utilization has led to notable advancements in printing highly complex structures on different substrates, as well as improvements in resolution and throughput, and the development of novel photosensitive materials, which impressively facilitated MPL's expansion into broader fields over the last few years. In this perspective article, the aim is to highlight these advancements and recent trends in MPL. The current challenges of MPL will be explored, which need to be addressed to ensure its further integration into advanced Additive Manufacturing at the micro- and nanoscale. The future perspectives and opportunities of MPL as a laser-based 3D printing approach will also be discussed. High-resolution laser-based 3D printing through multi-photon lithography (MPL) has recently gained enormous attractiveness across multidisciplinary fields over the past decade due to its versatility, adaptability, and flexibility. In this perspective article, recent advancements and trends in MPL are presented, while the challenges, perspectives, and future opportunities of this laser-based 3D printing approach are discussed. image