A novel 3D printEr for lArGe-area light-based additive manufacturing with uLtra-high rEsolution combining digital light procEssing and two-photon polYmErization

The processing of photosensitive materials upon the exposure of focused femtosecond laser radiation is referred to as two-photon polymerization, a powerful light-based Additive Manufacturing technique to fabricate 3D microstructures with ultra-high resolution.

Nonlinear phenomena convert photoresists or resins into the solid phase, whereby the process area is confined to the laser focus in which a solid building block is created with a possible size down to sub-100 nm.

In this way, two-photon polymerization enables the direct writing of arbitrary 3D structures by guiding the laser focus through the material. However, the writing scheme of two-photon polymerization is highly time-consuming. Thus, the technique has been unsuitable for large-area manufacturing of real-world products so far.

This research aims to engineer a novel, fully automated 3D printer that combines one-photon printing by digital light projection and two-photon polymerization.

In this way, the novel 3D printer will allow using the 3D structuring capabilities of two-photon polymerization on a large area.

Thus, this project will enable the lab-to-fab transfer of light-based Additive Manufacturing with an ultra-high resolution that will open new pathways to produce novel real-world devices, especially for healthcare. In this context, biodegradable and biocompatible resins will be employed.

The efficiency of two-photon polymerization will be further enhanced by digital mask projection using a digital mirror device, the same technique that is used for digital light processing. In addition, the printing process will be optimized using machine learning/artificial intelligence. A software will be developed to set the necessary printing settings.

The produced structures will be analyzed using scanning electron microscopy.

Finally, the novel 3D printer will be used to manufacture novel real-world devices for tissue engineering and Lab-on-Chip applications that will be characterized and tested afterwards.