Dual One and Two-Photon Solvent-Free Hybrid Photoresist for High-Resolution and Grayscale 3D Microprinting

Additive manufacturing holds a strong promise to revolutionize industry. Fabricating high-resolution and large objects with specific physical properties remains a critical challenge. In this direction, innovation in both chemical processing and 3D-printing techniques are needed. Here, a solvent-free hybrid organic-inorganic photoresist combining a radical photoinitiator and a photobase generator is photostructured by grayscale lithography and direct laser writing using both one- and two-photon absorption. Infrared spectroscopy suggests that one-photon absorption activates the photoinitiator and leads to radical polymerization of organic moieties, triggering silanol condensation in a synergetic way. In contrast, upon two-photon absorption, the driving force of polymer formation is the photobase-induced silanol condensation. The proposed approach produces both large area and high-resolution 3D structures upon one- and two-photon absorption induced polymerization, respectively. This new paradigm paves the way toward the efficient fabrication of on-demand devices for personalized health care, microfluidics, or microoptics. Microprinted hybrid materials have a strong potential to enable future applications in microfluidics, microoptics, or in catalysis. This study presents the combined grayscale one-photon and two-photon lithography processing of hybrid sol-gel materials obtained by a simple solvent-free synthesis resulting in large size and high-resolution structures.image (c) 2024 WILEY-VCH GmbH