Sometime in the future, surgeons will implant custom lenses that mimic the properties of actual human eyes, implants that are far better than those used today.

The same machine that turned out the lenses could also produce panels of SCHOTT NARIMA Color Effects glass, in a custom color, on demand, for an architect. Then, that same machine could fabricate laboratory glass uniquely suited to a specific line of research.

All of these could be made possible with glass 3D printers. SCHOTT is on the forefront of research and development into this promising field, supplying high-quality glass powder, pastes, rods, and tubing to developers like the Israeli 3D printer company MICRON3DP, as well as researchers from the Missouri University for Science and Technology.

These developments are bringing the quality of glass to a longstanding industry, expanding the potential of 3D printing to realize new products and even new business models across a number of fields.

3D glass printers come of age

3D printers have used plastics for more than three decades, with the first patent in the space issued to U.S. inventor Chuck Hall. It wasn’t until 2012 that researchers in both academia and industry took aim at 3D printable glass.

Early success was elusive. Products were cloudy, fragile, and full of air bubbles. There have been a few demonstrations of 3D glass printers that resulted in superior glass products, yet technical challenges still remain before glass printing becomes useful to technical, optical, or medical applications.

3D printing works by layering materials on top of one another, in much the same way that ink lays on top of paper in 2D printing. But printing with glass has turned out to be more complicated than plastics, because of the relatively high heat and narrow process window involved.

For example, if the heat is a little too low, the glass becomes rigid, and therefore doesn’t bond well. But if it is too high, is becomes viscous and will not hold a form. But done just right, 3D printed glass opens up a number of new possibilities.

Applications for 3D printed glass

At first, architects and designers showed the most interest in 3D printing glass. But more technical applications are coming, and these can require specific properties, like high transparency or resistance to thermal shock.

One potential application of 3D printers is creating smaller and more compact gradient index lenses. Most lenses, like those found in eyeglasses or telescopes, rely on the shape of the lens to gather and focus light. Gradient index lenses focus light like the human eye. Light in it refracts by passing through materials of different densities. Commercially available gradient index lenses are large, and usually require fusing multiple lenses together. By 3D printing a gradient index lens, manufacturers can produce a single lens that incorporates the same properties as the several lenses used today.

The development of 3D printing could also, as it has in other industries, lead to changes across the supply chain.

At the moment, SCHOTT produces some glass in enormous, multi-ton batches. If a customer requires more individualized pieces, such as jewelry or even organic lenses to improve vision, 3D-printing will allow us to customize colors, patterns, transparency, and other elements on demand.

Inventories of finished products could be smaller, with manufacturers making what they need, when it is ordered. An optical glass maker could fabricate the same custom telescope lens in 2017 that it had made in 1967. In the future, inventory will be digital.