Three-dimensional nanoprinting via charged aerosol jets.

Area of Science:

• Nanotechnology and Advanced Manufacturing
• Materials Science and Engineering
• Additive Manufacturing

Background:

• Three-dimensional (3D) printing has impacted various fields, but downscaling to the nanoscale faces material and purity limitations.
• Existing 3D nanoprinting methods often require polymer-metal mixtures or inks, restricting material choices and resulting structure purity.
• Aerosol lithography has enabled 3D metal nanostructure assembly but is limited to specific geometries.

Purpose of the Study:

• To develop a direct 3D nanoprinting technique for high-purity metal nanostructures with flexible geometries.
• To overcome the limitations of existing methods regarding material choice and structure purity.
• To demonstrate the capability of printing various 3D nanostructures and potential applications.

Main Methods:

• A novel dry-atmosphere printing process using ions and charged aerosol particles directed by electrostatic lenses.
• Utilizing a dielectric mask with holes floating over a biased silicon substrate to focus aerosol particles into nanoscale jets.
• Employing substrate movement during printing to create diverse 3D nanostructures, including helices, rings, and letters.

Main Results:

• Successful direct 3D printing of arrays of metal nanostructures with feature sizes down to hundreds of nanometers.
• Demonstration of printing various complex 3D geometries, including overhanging nanopillars and letters.
• Fabrication of an array of vertical split-ring resonator structures, showcasing potential applications.

Conclusions:

• The developed technique offers a versatile platform for 3D nanoprinting of various materials with high purity and flexible geometries.
• This method overcomes limitations of previous techniques by avoiding polymers and inks, enabling broader material selection.
• The technique is expected to significantly advance nanofabrication, especially when combined with other 3D printing approaches.