#3DStartup: Xolo and Volumetric 3D Printing

Last December, we presented xube, a compact 3D printer capable of printing parts in just a few seconds thanks to a volumetric printing process. Behind this innovation, is the young company Xolo. Based in Germany, it intends to change the rules of photopolymerization, by no longer relying on the classic approach of layer-by-layer printing. Xolo uses xolography, a technique that uses different initiators and two types of wavelengths to harden the resin. The result? A much faster manufacturing process, a smoother surface and more material possibilities. We met with one of xolo’s founders, Dirk Radzinski, to learn more about this technology and the benefits it offers.

Can you introduce yourself and your connection with 3D printing? How did the idea of creating xolo come up?

I am one of the co-founders of the company which is roughly 1 1/2 years old. Neither of the 3 founders have been working in the 3D printing industry before. Stefan hecht is a professor in chemistry Aachen university and director of the Leibniz institute for interactive materials. He is an expert in photoswitches. Martin Regehly is a physics professor in Brandenburg and former founder and CEO of a scientific camera company (greateyes). I am a serial entrepreneur having founded and sold companies in deep tech/deep science. The 3 of us are friends and before we had the idea for xolo we had the idea to do something together. But it took many years until we stumbled upon a nature paper in the summer of 2017 from the Lippert group. They described a new volumetric display. The very simple idea was to not have an image displayed but instead cure a photopolymer with a comparable set-up. The missing link were the molecules which can make that happen. We built them from scratch and developed a new class of photoswitch-initiator molecules.

The co-founders of the startup (photo credits: xolo)

Tell us more about xolography: how does it work?

xolography is a dual color volumetric 3d printing process. As in stereolithography it uses light to cure a photoresin. However, if you project light into a vat with transparent resin which contains initiators like in stereolithography, curing would occur along the whole lightpath. That is why SLA/DLP printers add absorbers to their resins. In xolography we developed a new type of initiator. This initiator does not start curing if it has been hit by light with a single wavelength. It needs two different wavelengths to start the polymerization process. Wherever blue and red light intersect and meet the initiator at about the same time, curing occurs.