A 2024 Science Advances study formulated an additive-free, water-based ink from the main structural components of wood—lignin and cellulose—and printed architected wood structures by direct ink writing (DIW).
A binder-free wood-based ink
The formulation used hardwood lignin, cellulose nanocrystals and TEMPO-oxidized cellulose nanofibers. A 25-gauge nozzle enabled printing resolution as fine as about 200 µm with interlayer spacing below 100 µm.
Freeze-drying and 180°C lignin fusion
Printed parts were freeze-dried at −85°C under vacuum for 48 hours, then heated at 180°C. Lignin softening and flow reduced interlayer voids by more than 50%; hot pressing further densified the material.
Stronger than balsa only in specific flexural comparisons
Double-hot-pressed samples showed about 198–222% higher modulus of rupture and 1,254–1,571% higher flexural modulus than natural balsa in the tested direction.
However, unpressed printed material had a compressive strength of about 1.51 MPa versus about 5.95 MPa for balsa and showed layer-separation failure. The correct conclusion is therefore that selected densified samples exceeded balsa in particular bending metrics—not that all 3D-printed wood is universally stronger than natural wood.
Recycling potential, but no life-cycle proof yet
The approach could use lignin and cellulose recovered from wood or other lignocellulosic streams, but the process requires 48-hour freeze-drying and high-temperature treatment. Energy use, cost and life-cycle benefits were not demonstrated.
For related context, see Coconut-Mat Layers Reduced Thermal Conductivity of a Geopolymer Panel by Up to 41%.
For related context, see Nanocellulose Fibers Retain Strength When Wet: Toward Cotton-Like All-Cellulose Filaments.
For related context, see Chitosan + Aloe + Cinnamon Produced Antimicrobial Cotton That Also Degraded in Soil Tests.
Reference
- Thakur MSH et al. Three-dimensional printing of wood. Science Advances. 2024;10:eadk3250. https://doi.org/10.1126/sciadv.adk3250
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