A new 3D printing technique, developed at Lawrence Livermore, could allow scientists to print glass that incorporates different refractive indices in a single flat optic, making finishing cheaper and easier. (Credit: Jason Laurea/LLNL).

Scientists have demonstrated the synthesis of transparent glass through 3D printing, a development that could ultimately lead to altering the design and structure of lasers and other devices that incorporate optics. The technique enables glass structures and composition gradients previously impossible through conventional manufacturing processes.

Custom inks are formed from concentrated suspensions of glass particles with highly controlled flow properties so they can be printed at room temperature. The printed components then undergo a carefully designed thermal treatment to densify the parts and remove evidence of the printing process. Finally, the processed parts are given an optical quality polish. The approach improves the odds of achieving optical uniformity.

The research could allow scientists to print glass that incorporates different refractive indices in a single flat optic, as opposed to the special shapes that are required for constant composition glasses to achieve similar lensing characteristics. Due to the ability to program the composition, printed components would be easier and cheaper to finish.

While the research could expand the design space for optical engineers, it also may have applications outside of optics, including glass microfluidic devices that have complex and previously unobtainable layouts. Glass is a prized material for microfluidics due to its optical transparency, chemical resistance, mechanical properties, and ability to tailor its surface chemistry and functionality.

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