From Single to Multi-Glass/Ceramic Microarchitectures via Two-Photon Lithography

Two-photon lithography (TPL), as an additive manufacturing (AM) technique, facilitates the low-temperature fabrication of microarchitectures, yet the integration of spatially varying inorganic compositions within a microarchitecture footprint remains largely unexplored. This work examines the transition from single to multi-material manufacture and, study the optical properties of SiO₂ glass and its combination with inorganic loadings. The latter approach, i.e., multi-composition printing, is evaluated using a fluidic cell for photoresin exchange, enabling spatially varied patterning. Using thermal annealing at 650 °C, single- and multi-inorganic printed replicas are produced with tailored chemical components. Yet, even though state-of-the-art photoresins are well-optimized for single-material printing (e.g., SiO₂, TiO₂, and ZrO₂), the necessity of adjusting photoresins is highlighted for multi-material printing. Annealed multi-printed replicas rely on composition-specific photoresins, such as the inorganic mass fraction, which can significantly influence the fidelity of the post-annealed microarchitecture. Additionally, insights into these microarchitectures' chemical, morphological, and optical behavior are provided through characterization methods, including scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), confocal fluorescence microscopy, and cathodoluminescence (CL). The results highlight the importance of formulation and processing conditions for achieving inorganic multi-printing.