3D printing glass has always been a cutting-edge subject for researchers. We rarely see research reports of breakthroughs in this regard. In addition to the high melting point of glass, it is also hard to print its dense structure. Researchers from the ICMCB-CNRS laboratory and the University of Bordeaux have developed a method of 3D printing phosphate glass via FDM technology. 

It is reported that the 3D printed phosphate glass retains the physical properties of the glass with a porosity percentage of 0.02%. The researchers first pull the glass filament from the parent glass preform using a fiber drawing tower, then fabricate the highly-dense and transparent europium-doped phosphate glass structure with a 3D printer using the fused deposition modeling (FDM) process. The team believes that its direct approach to fabricating transparent glass gives rise to the possibility of cutting-edge optical components and new biomedical devices. 

Phosphate glass is an example of optical glass, a material with refractive properties that makes it perfect for lenses, optical fibers, and other components in optical systems. The 3D printing of such material has largely eluded scientists for many years due to unwanted opacity changes and certain crystallization phenomena. 

One of the most striking findings in the study was that the 3D printed glass structures maintained their optical luminescence properties, meaning they displayed homogenous light transmission throughout. This property is absolutely crucial in any high-tech optical system, so the work shows great potential in providing a cost-effective method of end-use component production.