During my research work at the Institute of Landscape Architecture at RWTH Aachen University, I focused extensively on the Cologne Forest Laboratory (Waldlabor Köln) and the potential of future forest landscapes and forms. In 2021, the idea emerged to use fast-growing wood – including willow – for 3D printing. My long-time colleague and 3D printing expert Federico Garrido just said, “That’s not possible, no one’s doing that.” That was when I knew we had to try it – and the idea for Willowprint, sustainable 3D printing with wood, was born.

Essentially, the paste consists of wood components, which we now source from residues from the wood industry. Natural binders and stabilizers are added to give the paste its smoothness during printing and its required strength once hardened. This sets our technology apart from many others that use less environmentally friendly additives. Together with RWTH Innovation, we were able to file a patent for both the formulation and the technology.

Additive manufacturing (the 3D printing process) offers many advantages over conventional methods – when used correctly. We use by-products from the wood industry to create a building material for the future. The process generates minimal waste, requires no additional formwork or molds, and enables the printing of objects that already incorporate multiple design aspects. After production, the individual modules can be assembled – like Lego – into large-scale structures. It's the combination of design, technology, and material that makes Willowprint so unique.

Within the Willowprint research project, we’ve already printed a variety of design objects – such as small pieces of furniture, lamps, and urns. Our vision is to manufacture large-scale components for use in temporary architecture. These could include trade fair booths, eco-resort bungalows, or temporary student housing in times of housing shortages. Achieving this still requires further research and development.

We started the project from scratch four years ago and depend on external funding. On our journey toward becoming a start-up, we’ve received support from RWTH Aachen University and the Innovation Promotion Agency of North Rhine-Westphalia, co-financed by the EU. That support made the project possible in the first place.

The material consists exclusively of natural raw materials – residues from the wood industry – and is completely recyclable and compostable. That has been important to us from the very beginning. During the development of the technology – for example, to print larger and more stable structures – we continuously carried out sustainability tests. We even used standard household compost boxes to “feed” worms with our material. The worms tolerated it well, and humus was produced as a result. Of course, that’s just a starting point and still needs further testing and validation. Through our work, we want to contribute to the circular use of biogenic raw materials.

Interview: Lea Holzamer