The University of Virginia scientists have developed 3D-printed living soil walls that can support plant growth. They have been able to produce 3D-print soil structures which can grow plants on their surfaces.
The research papers were published in Additive Manufacturing in April, using 3D printing with seed-impregnated soil that could be used to create plant-filled walls and roofs.
The creators of this UVA project are Ji Ma, David Carr, and Ehsan Baharlou. They demonstrate that a system integrating 3D printing and bio-based construction can be used to construct complicated shapes out of soil with seeds. The prototypes developed by them look similar to ordinary raw-earth structures, though they sprout and become covered in greenery after a few days.
According to Baharlou, “We moved to soil-based ‘inks’ to derive additional benefits from circular additive manufacturing. We are working with local soils and plants mixed with water; the only electricity we need is to move the material and run a pump during printing. If we don’t need a printed piece or if it isn’t the right quality, we can recycle and reuse the material in the next batch of inks.”Combination of Dirt and Seed
Spencer Barnes, one of the students who contributed to the research, experimented with soil-based inks. Using a desk-sized 3D printer, he tested two methods: printing soil and seed in successive layers and combining dirt and seed before printing. Both methods were effective. Barnes created a cylindrical prototype that resembled a Chia pet.
Baharlou then proposed 3D-printing soil structures with more complex geometries, such as domes.
3D printed soil retains water, while the environment around plants tends to be drier. This is because of the lack of air within the soil. When squeezed through a nozzle, bubbles are pushed out and within the soil, water becomes more tightly held with less air.Make or Break
Recently, scientists 3D printed low forms at the rate of 1 meter tall. They then plan to attach their 3D printer to a moving robot that produces complex constructions with many sides. However, they will have to refine the recipe for these “soil inks”.
Additive manufacturing allows you to take advantage of opportunities in your material system. This entails some challenges that you may have never encountered before, so you need to try to control these challenges and use them to your advantage.