Microscale Metal Additive Manufacturing by Solid-State Impact Bonding of Shaped Thin Films.

Area of Science:

• Materials Science
• Manufacturing Engineering
• Nanotechnology

Background:

• Additive manufacturing (AM) faces challenges in depositing device-grade inorganic materials for microfabrication.
• Existing methods for metal AM lack the material quality, throughput, and material versatility of traditional thin-film deposition.

Purpose of the Study:

• To introduce a novel method for the additive assembly of high-purity, high-density metals with micrometer-scale precision.
• To establish kinetic, solid-state bonding as a viable route for micro-scale AM of metals.

Main Methods:

• Indirect laser ablation to accelerate metal thin films to high velocities (hundreds of m/s) without heating or ablation.
• Solid-state bonding achieved through the kinetic impact of accelerated thin films on a substrate above a critical velocity.
• Integration with lithographic methods for precise definition of thin-film layers prior to transfer.

Main Results:

• Demonstrated high-density metal layers (>99%) formed via solid-state kinetic bonding.
• Achieved micrometer-scale precision (2-50 µm feature size) and arbitrary shapes for bonded layers.
• Showcased parallel transfer of up to 36 independent film units in a single laser shot, indicating high throughput potential.

Conclusions:

• Kinetic, solid-state bonding is established as a promising new principle for micro-scale additive manufacturing of metals.
• The method offers a pathway to high-quality, high-density metal structures with precise control over feature size and shape.
• This technique has the potential to bridge the gap between AM capabilities and established thin-film deposition quality for metals.