Holographic Projections Improve Efficiency in Volumetric 3D Printing

A research team from EPFL and the University of Southern Denmark has developed a method that significantly improves the efficiency and resolution of tomographic volumetric additive manufacturing (TVAM). By using holographic projections, the researchers were able to drastically reduce energy consumption while increasing detail accuracy. The findings were published in Nature Communications and highlight the potential of this technology for future applications in 3D printing.

In the TVAM process, laser light is projected into a rotating resin container until the accumulated energy at certain points exceeds a threshold, causing solidification. Compared to layer-based 3D printing methods, TVAM has the advantage of producing objects within seconds. However, the method has been inefficient, with only about one percent of the light contributing to curing the resin.

“We are interested in using our approach to build 3D complex shapes of biological structures, allowing us to bio-print, for example, life-scale models of tissues or organs,” says EPFL student and lead author Maria Isabel Alvarez-Castaño.

The research team, led by Christophe Moser and Jesper Glückstad, addressed this issue by incorporating three-dimensional holograms. While conventional TVAM encodes information in the amplitude of light waves, the new method utilizes their phase. This allows for better control over projection depth and higher spatial resolution.

Using this technique, the researchers printed complex 3D objects such as miniature boats, spheres, and artistic designs in under 60 seconds with significantly reduced optical power. Only a fraction of the energy previously required was used. Additionally, the HoloTile technology employed eliminates unwanted light interference and enhances image quality.

Another promising application of this technology lies in biomedicine. The team plans to use holographic TVAM techniques to print complex biological structures, such as realistic tissue and organ models. Since the holographic beams possess self-healing properties, they can be used with bio-resins and hydrogels without scattering effects affecting precision.

Looking ahead, the researchers aim to further improve the method’s efficiency. One goal is to eliminate the need for resin container rotation, allowing objects to be formed solely by projecting a hologram onto the liquid. This could simplify the process and make it more suitable for large-scale applications. The fact that the required holograms can be encoded using commercially available hardware further enhances the practicality of this approach.