Kiel team prints and fuses glass directly by laser – prospects for implants and photonics

Researchers at the Christian-Albrechts-Universität zu Kiel report an additive process that locally melts glass powder during printing and immediately solidifies it into dense, transparent structures. “Laser-Assisted Melt Printing” (LAMP) combines a silica-based particle ink with short, high-energy laser pulses. The results were published in the journal Materials & Design and address typical bottlenecks of conventional glass and ceramic printing, which usually require a subsequent furnace firing.

In the LAMP process, the ink is deposited layer by layer and fused with pinpoint precision. By controlling laser power and writing speed, the team tunes surface roughness, density, and transparency already during consolidation. Electron microscopy and spectroscopy show fully densified areas without air inclusions.

“LAMP makes it possible to control physical properties such as density, smoothness, color, and transparency during printing,” says Dr. Leonard Siebert, who led the study.

Special attention is paid to optical functionalities. The addition of gold and silver ions leads to the formation of metal nanoparticles during laser melting, whose size determines spectral transmission.

“These nanoparticles act like tiny filters: they allow only certain wavelengths to pass and block others,” explains Kolja Krohne, who was also involved in the study.

“In conventional processes, ceramics usually have to be fired in kilns at well over 1000 °C. That consumes a lot of energy, takes a long time, subjects parts to high stresses, and makes it difficult to produce delicate or patient-specific implants,” explains Siebert.

Beyond glass, the authors see opportunities for biomedical ceramics, such as patient-specific dental and bone implants. Classic sintering temperatures above 1,000 °C are eliminated, reducing process time and thermomechanical loads. A prior collaboration with the University Medical Center Schleswig-Holstein already demonstrated the feasibility of dental ceramic components in 2023—then still with furnace firing. The team is working to transfer LAMP to these systems to evaluate energy-efficient, additively assisted manufacturing with precisely tunable material properties in regulated applications.