Femtosecond-Laser Direct Writing of Metallic Micro/Nanostructures: From Fabrication Strategies to Future Applications

The past decade has seen growing research interest in developing novel fabrication methodologies for metallic micro/nanostructures toward the rational design and integration of 0D to 3D metallic configurations. Among the various fabrication techniques, femtosecond-laser direct writing has emerged as a prominent approach to reach this goal and greatly facilitates the development of metallic micro/nanostructure-enabled applications. Here, a series of femtosecond-laser-mediated fabrication strategies, including the two-photon reduction of metal ions, template-assisted metal coating and metal filling, photodynamic assembly of metal nanoparticles, and selective nanoparticle sintering, are summarized. Additionally, abundant applications in microelectronics, metamaterials, near-field optics, microfluidics, micromechanics, and microsensors are introduced in detail. Current challenges and future perspectives in this field are also discussed.