3D printing of wood typically relies on an approach called ‘fused deposition modelling’. Here, wood is ground up into fine particles, and mixed with melted thermoplastic, which can then be deposited in thin layers before it hardens.

However, this technique comes with two key drawbacks: not only does the plastic require large amounts of energy to melt, but only a limited proportion of wood can be used in the mixture to maintain desirable material properties in the final product.

Through their research, Dr Michael Rosenthal at TU Dresden, together with Uwe Bodenschatz at University of Applied Sciences Zwickau, show how the 3D printing of wood can be improved with an alternative technique called Liquid Deposition Modelling (LDM).

The team’s approach was inspired by the building habits of wasps. To construct their nests, wasps mix crushed wood particles with their own saliva to form a pulp, which becomes remarkably rigid when it dries. To imitate the process, Rosenthal and Bodenschatz started with a cellulose binder derived from natural plant fibers. After dissolving the binder in water, they mixed it with fine wood particles, creating a mixture that hardens as it dries out.

Using a specially designed 3D printer, the researchers then sculpted their material into a variety of structures: including parts for a stool and a small coffee table. They repeated the process several times using varying proportions of wood in the mixture, before testing the final products.

Their results were promising. Through LDM, they could produce materials whose mechanical strength makes them well suited for use in furniture. As well as being more energy efficient than previous approaches, LDM also enabled them to increase the proportion of wood in the mixture to up to 90%, while maintaining both processability and strength.

Through further development, the team’s approach paves the way for substantial improvements in sustainability for the wood manufacturing industry.