Additive and Substractive Surface Structuring by Femtosecond Laser Induced Material Ejection and Redistribution

Area of Science:

• Materials Science
• Surface Engineering
• Additive Manufacturing

Background:

• Traditional surface modification techniques have limitations in creating complex 3D structures.
• Achieving robust and functional surfaces often requires multi-step processes.

Purpose of the Study:

• To develop a novel additive surface structuring process using femtosecond laser irradiation.
• To demonstrate the fabrication of micro-scale 3D structures with controlled geometry and enhanced functionalities.

Main Methods:

• Localized, intense femtosecond laser irradiation inducing phase explosion and material ejection.
• Controlled deposition and accumulation of ejected species to build 3D structures.
• Subsequent subtractive ablation for further geometry modification.

Main Results:

• Formation of µm-scale 3D structures surpassing the initial surface level.
• Quasi-seamless conjugation and mechanical robustness between substrate and grown structures.
• Fabrication of re-entrant structures and pillars on aluminum substrates, including superhydrophobic surfaces.

Conclusions:

• The proposed additive surface structuring process is effective for creating complex, robust, and functional micro-scale 3D structures.
• The method allows for precise control over geometry and patterning.
• This technique offers a versatile platform for engineering surfaces with desired properties.