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.