The University of Virginia is 3D printing living structures that plants can grow on > Virginia

The University of Virginia is 3D printing living structures that plants can grow on

Researchers from the University of Virginia developed 3D-printed walls from soil in which seeds were planted.

“Why do we have to design it so that the structure or building is separate from the nature in which it stands?” wondered Ji Ma, assistant professor of materials science and engineering at the UVA School of Engineering and Applied Science. Ma worked with David Carr, a research professor in the University of Virginia School of Environmental Sciences, and Ehsan Baharlou, an assistant professor in UVA’s School of Architecture, to answer this question.

The University of Virginia is 3D printing living structures that plants can grow on
The University of Virginia is 3D printing living structures that plants can grow on
© Photo courtesy of E. Baharlou

They have demonstrated the feasibility of 3D printing geometrically complex structures from soil and seeds, ushering in a major innovation in bio-based design. UVA researchers are taking 3D printing one step further by combining speed, cost-efficiency, and energy-saving and bio-based materials.

“We switched to earth-based ‘inks’ to gain additional benefits from circular additive manufacturing,” said Ehsan Baharlou. “We work with local soils and plants mixed with water; We only need electricity to move the material and run a pump while printing. If we don’t need a printed piece or it’s not of the right quality, we can recycle the material and reuse it in the next batch of ink.”

Barnes experimented with earth-based inks with the help of Harrison Grant of the University of Virginia. He experimented with two methods, printing soil and seeds in sequential layers and mixing the seeds and soil before printing with a desk-sized 3D printer. Both approaches were successful. Barnes created a cylindrical prototype the size of a soda can that resembled a chia pet.

The University of Virginia is 3D printing living structures that plants can grow on
© Photo courtesy of E. Baharlou

Baharlou suggested using soil structures with more complex geometries, such as B. Domes to 3D print. The research team, which included Leah Kirssin, who will graduate with a Bachelor of Science in architecture in 2021, and Lizzie Needham, who will graduate with a Master of Landscape Architecture in the same year, tested how material comes out of the printhead or nozzle, as an extrusion known method, without adding additives to the soil mixture. This collaborative effort showed that 3D printed soil structures can support plant growth, but are most likely limited.

© Photo by Tom Daly

“3D-printed soil tends to lose water faster and has a tighter grip on the water it has,” Ma said. “Since 3D printing makes the plant’s environment drier, we need to include plants that like drier climates. We believe this is because the soil is being compacted. When the soil is pushed through the nozzle, air bubbles are pushed out. As the soil loses air bubbles, it holds the water tighter.”

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