Digital 3D laser printing of solid glass

• Applicant: Dr. Jürgen Ihlemann
• Subject Area: Synthesis and Properties of Functional Materials
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 464599575

Digital additive manufacturing of glass in the solid phase by laser induced forward transfer printing will be explored here for the first time. This process will enable the fabrication of micro devices of pre-functionalized glass (e.g. doped, patterned, or locally modified by laser based or other methods). Compared to often used polymeric materials, glass has superior optical, thermal and mechanical characteristics for use e.g. in optical communication technology, optical sensors, and microfluidics. The glass will be prepared in form of a few µm thick “donor” films (SiO2 or borosilicate glass) deposited on transparent carrier substrates. With the help of lasers we will try to build micro-sized glass components according to the „Lego“-principle. Glass Lego bricks with a height in the µm-range and a width of a few ten µm are deposited (“printed”) side by side and on top of each other. The difference to classic Lego is, that the bricks are not taken from a reservoir (which would be extremely difficult when working on the micro scale), but they are cut out of the prepared “donor” glass film and transferred “digitally” one by one (or parallelized set by set) to the suitably positioned receiver plate. Both, the cutting out and the transfer are performed in one step with the same nanosecond ultraviolet laser pulse. The use of additional absorber and adhesion layers addressing the specific challenges of laser glass processing is explored. With this process, significantly smaller feature sizes can be obtained compared to the existing method of casting a glass melt. Because of only moderate thermal load, the internal and in future applications intentionally modified functional structure of the glass bricks is preserved. If this kind of printing of solid glass parts is successful, a toolkit for creating complex micro- and nanosystems in glass can be established. Systems composed of parts with completely different pre-processing can be assembled on a single platform. Inscribed waveguides and gratings and ablated nanochannels or grooves can be combined, or doped glass can be printed aside glass with implanted plasmonic particles. In combination with the already established processes for printing polymers, pastes and metals, this glass printing will enable real multimaterial processing by laser induced transfer. This shows a route for microfabrication of mixed electronic/photonic/plasmonic circuits and systems.

• DFG Programme: Research Grants