In Situ Collection of Nanoparticles during Femtosecond Laser Machining in Air

Area of Science:

• Laser Material Processing
• Nanoparticle Science
• Surface Engineering

Background:

• Laser-generated nanoparticles are typically waste products in laser material processing.
• Effective collection and potential reuse of these nanoparticles remain a challenge.
• Femtosecond laser machining generates nanoparticles that require in situ management.

Purpose of the Study:

• To investigate dominant factors in nanoparticle removal and collection during laser machining.
• To establish an in situ nanoparticle removal method for femtosecond laser processes.
• To evaluate the influence of electrical charge conditions on nanoparticle behavior.

Main Methods:

• Parametric study involving laser machining of Copper (Cu), Titanium (Ti), and Silicon (Si).
• Machining performed under three charge conditions: no external charge, floating potential, and applied field.
• Analysis of plume deflection, nanoparticle accumulation, and redeposition under different charge conditions.

Main Results:

• Both floating potential and applied field strategies effectively collected laser-generated nanoparticles.
• Applied field condition resulted in the strongest nanoparticle plume confinement and collection pattern.
• Raster-scanning direction influenced collection patterns and ablation depth, but not target surface integrity.

Conclusions:

• Machining under floating potential or applied field is a viable strategy for in situ nanoparticle removal.
• This approach offers a promising pathway towards circular, waste-free laser process design.
• Potential for controlled collection of nanoparticles for subsequent applications.