A sinterless, low-temperature route to 3D print nanoscale optical-grade glass

J. Bauer; C. Crook; T. Baldacchini

Science 380 (2023) 960-966

Three-dimensional (3D) printing of silica glass is dominated by techniques that rely on traditional particle sintering. At the nanoscale, this limits their adoption within microsystem technology, which prevents technological breakthroughs. We introduce the sinterless, two-photon polymerization 3D printing of free-form fused silica nanostructures from a polyhedral oligomeric silsesquioxane (POSS) resin. Contrary to particle-loaded sacrificial binders, our POSS resin itself constitutes a continuous silicon-oxygen molecular network that forms transparent fused silica at only 650°C. This temperature is 500°C lower than the sintering temperatures for fusing discrete silica particles to a continuum, which brings silica 3D printing below the melting points of essential microsystem materials. Simultaneously, we achieve a fourfold resolution enhancement, which enables visible light nanophotonics. By demonstrating excellent optical quality, mechanical resilience, ease of processing, and coverable size scale, our material sets a benchmark for micro? and nano?3D printing of inorganic solids. Printing glass with additive manufacturing techniques could provide access to new materials and structures for many applications. However, one key limitation to this is the high temperature usually required to cure glass. Bauer et al. used a hybrid organic-inorganic polymer resin as a feedstock material that requires a much lower temperature for curing (see the Perspective by Colombo and Franchin). The ability to form transparent, fused silica at only 650°C opens up different uses for the material. The glass produced has excellent spatial resolution, optical quality, and mechanical properties. ?Brent Grocholski A hybrid organic-inorganic polymer resin creates sinter-free glass at lower temperatures.

DOI: https://doi.org/10.1126/science.abq3037