Metasurface-Enabled Holographic Lithography for Impact-Absorbing Nanoarchitected Sheets

Area of Science:

• Materials Science
• Nanotechnology
• Additive Manufacturing

Background:

• Nanoarchitected materials offer unique properties like low density and high energy absorption.
• Existing fabrication methods lack scalability and sub-micrometer resolution for large-area production.
• There is a need for advanced manufacturing techniques for these advanced materials.

Purpose of the Study:

• To present a novel fabrication technique for producing nanoarchitected materials.
• To characterize the mechanical properties and energy absorption capabilities of the fabricated materials.
• To demonstrate the potential of holographic lithography for scalable manufacturing.

Main Methods:

• Holographic lithography using laser-exposed phase metasurface masks in negative-tone photoresists.
• Fabrication of 30-40 µm-thick nanoarchitected sheets with ≈500 nm-wide struts in 3D brick-and-mortar patterns.
• Nanoindentation arrays and laser-induced particle impact tests (LIPIT) for mechanical characterization.

Main Results:

• Achieved ≈50-70% porosity with layered 3D brick-and-mortar structures over 2.1 × 2.4 cm² areas.
• Measured out-of-plane elastic modulus ranging from 300 MPa to 4 GPa, with deformation via nanostrut buckling and cracking.
• Demonstrated specific inelastic energy dissipation of 0.51-2.61 MJ kg⁻¹, comparable to high-performance composites.

Conclusions:

• Holographic lithography is a viable and scalable platform for manufacturing nanoarchitected materials.
• The fabricated materials exhibit excellent impact energy absorption capabilities.
• This technique opens new avenues for designing advanced materials with tailored mechanical performance.