Adding chemically selective subtraction to multi-material 3D additive manufacturing.

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Conventional photoresists for 3D laser lithography often require harsh conditions for post-development removal.
• Subtractive manufacturing methods for microstructures face challenges with material compatibility and process harshness.

Purpose of the Study:

• To develop novel chemoselectively cleavable photoresists for 3D laser lithography.
• To enable targeted degradation of 3D printed microstructures under mild, controllable conditions.
• To facilitate advanced subtractive manufacturing at the micro- and nanoscale.

Main Methods:

• Synthesis of three bifunctional silane crosslinkers with varied silicon substitutions.
• Formulation of photoresists by combining silane crosslinkers, pentaerythritol triacrylate, and a two-photon photoinitiator.
• Fabrication of 3D microstructures using direct laser writing and subsequent cleavage in a methanol solution with inorganic salts.

Main Results:

• The developed photoresists allow for targeted degradation of 3D printed microstructures under mild conditions.
• Pentaerythritol triacrylate incorporation improved resolution of direct laser written structures while maintaining cleavability.
• Selective cleavage of photoresists was achieved, enabling sequential degradation of microstructures.

Conclusions:

• Chemoselectively cleavable photoresists based on silane crosslinkers offer a breakthrough for mild-condition subtractive manufacturing in 3D laser lithography.
• The ability to selectively degrade microstructures opens new possibilities for complex, multi-material fabrication at the micro- and nanoscale.
• This technology advances subtractive manufacturing, enabling precise control over material removal in 3D printed constructs.