Light used to “grow” objects

The resin can be processed using commercially available Digital Light Processing technology. This involves irradiating the resin with UV light patterns. Wherever the light strikes the resin, it hardens because the light sensitive components of the polymer resin cross link at the exposed points. The plastic monomers combine to form a labyrinth-like structure, creating the polymer. The ceramic-bearing molecules fill the interstices of this labyrinth.

An object can thus be built up layer by layer. The researchers can change various parameters in each layer, including pore size: weak light intensity results in large pores; intense illumination produces small pores. “We discovered that by accident, but we can use this to directly influence the pore size of the printed object,” says Masania.

The researchers are also able to modify the microstructure, layer by layer, by mixing silica with borate or phosphate and adding it to the resin. Complex objects can be made from different types of glass, or even combined in the same object using the technique.

The researchers then fire the blank produced in this way at two different temperatures: at 600˚C to burn off the polymer framework and then at around 1000˚C to densify the ceramic structure into glass. During the firing process, the objects shrink significantly, but become transparent and hard like window glass.