It’s not uncommon to hear the refrain that 3D printing, as it stands today, is overly reliant on fossil-based materials. Still, there is a massive push for materials with more biodegradability and a lower carbon footprint. Although many research projects have employed green materials like hemp or peat, paper and woods have been scarce. Researchers at Sweden’s Chalmers University of Technology are looking to address this using sustainable nanocellulose and wood-based inks.
The researchers have managed to mimic the ‘ultrastructure’ of wood, thus deriving wood biopolymers. These wood-based materials don’t just pass through the extruder, they grow in shape as well. As the researchers state in the abstract, the “printed structures were locked by an enzymatic crosslinking reaction similar to what occurs in the cell wall upon lignification“.
As a result, the wood-based ink mimics the biogenesis of the real thing. The process also replaces the genome of the wood with G-code. This mixture of machines and biocompatible materials creates a fusion of design and natural growth. While the process relies heavily on printed models, it also relies on the nanocellulose gel’s natural enzymes.
The materials come from wood, but are not entirely grown. This also means that wood-based products could grow faster than the time needed for standard wood. They could also adapt into shapes to create packaging and boxes if needed. This sort of technology could severely curb the usage of standard plastics with the correct implementation.
Developing Nanocellulose Gels
“This is a breakthrough in manufacturing technology. It allows us to move beyond the limits of nature, to create new sustainable, green products. It means that those products which today are already forest-based can now be 3D printed, in a much shorter time. And the metals and plastics currently used in 3D printing can be replaced with a renewable, sustainable alternative,” says Professor Paul Gatenholm, who has led this research through the Wallenberg Wood Science Centre at Chalmers.
The materials originally came from wood pulp. The researchers converted the pulp into a nanocellulose gel and could thus print it. They then translated the wood’s genetic code into a G-code for proper predictive control. However, the gel was still less cohesive than they desired, so it needed some tweaking still. They then added hemicellulose to act as a sort of glue for the layers.
The process has already undergone extensive testing. The researchers demonstrated it at a workshop at the European Space Agency, ESA. They are also working with Florida Tech and NASA on the development of tests for these materials in microgravity situations. Hopefully, green products will lead to a more sustainable way of living in the near future.
Featured image courtesy of Yen Strandqvist, Chalmers University.
