Seeing the Light: Transparent Wood Could Replace Window Glass

biomass fuels transparent wood
Amber Plante, ERS, for Zondits

Researchers at the University of Maryland and, in a separate study, the KTH Royal Institute of Technology in Stockholm have created an innovative and highly insulating material that could one day revolutionize the way buildings are made. It’s wood – but not your typical lumber, of course: the team has discovered how to strip away the color molecules, thereby rendering the wood colorless and, in essence, see-through.

Using a boiling cocktail of water, hydrogen peroxide, and other chemicals, the Maryland team was able to remove a block of linden wood’s lignin, the molecule that gives it its rigidity and brown color. They followed this bath with an epoxy treatment , ending with a transparent piece of wood that is actually up to six times stronger than the untreated wood.

In the Stockholm project, published in the American chemical journal Biomacromolecules, only a few weeks before the Maryland study, the team also created a two-step process to turn wood transparent. According to project lead Lars Burgen, “Wood is by far the most used bio-based material in buildings. It’s attractive that the material comes from renewable sources. It also offers excellent mechanical properties, including strength, toughness, low density, and low thermal conductivity.”

This new natural material, which looks a bit like cloudy plastic, could be the next rage in renewable building materials. The natural channels that are present in the wood do not create the same scattering effect that glass has on light, thus allowing more light to pass through it. The applications of this technology could improve daylighting abilities and even winter heat retention in buildings of all sizes, from homes to large office complexes.

The commercial drawback to the technology at present is its scalability. While the Maryland team has been able to replicate the transparency process on thicknesses from paper-thin to 1 cm, they have only worked with blocks that are 5”-×-5” – roughly the size of a human palm. According to a recent New York Times article, they are working on fixing this issue.