What was concrete and meat already? In the near future, wood can also be 3D printed

Cutting down trees and treating wood is not the most efficient or environmentally friendly way of making furniture or building. At present, wood may be a renewable resource, but humans are using it much faster than replenishing it. Deforestation is having a dramatic impact on wildlife and exacerbating the effects of climate change. Since people's craving for wooden products is unlikely to change, what needs to change are the methods of making them.

In recent years, researchers have turned to growing wood in the lab. Of course, they are not trees, but trees. It's also not like growing animal cells for meat in a lab, instead of growing animals live and slaughtering them.

When wood can be 3D printed, people will not need to cut trees as much as they do today.

And now, a team of MIT scientists have demonstrated a new technique that can "grow" a wood-like plant material in the laboratory, allowing for easy adjustment of properties such as weight. and durability when needed.

'The idea is that you can grow these plant materials in exactly the shape you need, so you won't need to do any cutting production, and this cuts down on energy. as well as waste," said Ashley Beckwith, lead author of the study. "There's a lot of potential to extend this and develop three-dimensional structures."

The team first isolated cells from the leaves of a plant called Zinnia elegans. These cells were then cultured in liquid medium for two days, before being transferred to a denser gel medium. This gel contains nutrients and two different plant hormones, whose levels can be adjusted, to alter the physical and mechanical properties of the material.

Next, the team 3D printed the gel containing the cells into a specific shape, in the same way that people 3D print a plastic object. After three months of incubation in the dark, the material is dehydrated and the end result is a custom object made from a wood-like plant material. For example, in one experiment, the team shaped the material into a model of a tree.

A diagram illustrating how plant cells can be cultured and 3D printed into custom shapes, with different properties based on different levels of additional hormones.

The team experimented with different levels of the hormone and found that lower levels resulted in a lower density material, with open, circular cell textures. Meanwhile, high levels make them smaller, with a denser and stiffer structure, thanks to the increased growth of lignin (the second most abundant natural polymer in the world, after cellulose only) ). This difference can be used to create products with characteristics that are softer and lighter, or stronger and stiffer, if needed.

Ultimately, the goal of the research is to develop the technology to the point where wooden objects can essentially be 3D printed, instead of having to be cut, shaped and assembled from large pieces of wood obtained from felling trees. The process can start with small wooden objects or decorations, before moving on to furniture or planks for construction.

The next step, the team says, is to find ways to apply this method to other plants. Zinnia isn't a tree, so tweaking the process to make things work with something like pine could be a huge breakthrough.

The study was published in the journal Materials Today.