Low-temperature method for 3D printing nanoscale optical-grade glass

A hybrid organic-inorganic polymer resin enables the three-dimensional (3D) printing of nanoscale optical-grade glass at temperatures roughly half of what other approaches require, researchers report. According to the authors, the approach may help redefine the paradigm for the free-form manufacturing of silica glass and enable its use across a wide variety of new technological applications. Silica glasses possess a unique combination of properties, making them one of the most important materials for modern engineering applications. Their optical transparency, and their thermal, chemical, and mechanical characteristics make them ideal for various microsystem technologies, including micro-optics, photonics, microelectromechanical systems, and microfluidics. However, conventional glass manufacturing methods rely on high temperatures and/or forming techniques that limit how small a component can be made. Although techniques for 3D printing glass at nanoscales using two-photon polymerization (TPP) have greatly advanced, the temperatures required for sintering of particle-based silica glass resins often exceed the melting points of other materials used in electrical circuits, making on-chip manufacturing of glass components unfeasible. To address these limitations, Jens Bauer and colleagues developed a sinter-free, TPP 3D printing approach for creating free-form fused silica nanostructures. Using a polyhedral oligomeric silsesquioxane (POSS) resin as a feedstock, the authors demonstrate the ability to 3D print transparent fused silica glass nanostructures at only 650 degrees Celsius, which is roughly 500°C lower than the sinter temperatures required by other approaches, bringing the manufacturing temperatures below the melting points of essential microsystem materials and components. What’s more, the high-resolution glass structures produced by Bauer et al.’s method exhibit excellent optical qualities, enabling their use in visible light nanophononics. “The limited firing temperature requirement of the approach demonstrated by Bauer et al. allows in principle for the fabrication of miniaturized devices directly onto substrates, such as optical fibers and chips, which could enable process automation and high precision,” write Paolo Colombo and Giorgia Franchin in a related Perspective.