See-Through Wood to Brighten Buildings


Buildings of the future may utilize a material capable of providing interior spaces with ample amounts of daylighting. Hint: It’s not glass.

It’s something called “transparent wood.”

Swedish scientists report that they have developed a wood material that allows light to pass through. Potential applications of the technology include solar cells, windows and semi-transparent facades.

The scientists from Stockholm’s KTH Royal Institute of Technology recently published their findings in the American Chemical Society’s journal Biomacromolecules.

The Discovery

Recent research aimed at making transparent paper from wood was said to have inspired the team, led by Lars Berglund, a professor at the Wallenberg Wood Science Center at KTH.

Berglund and his colleagues reportedly removed lignin from samples of commercial balsa wood. Lignin is a structural polymer in plants that blocks 80 to 95 percent of light from passing through, according to the American Chemical Society.

“When the lignin is removed, the wood becomes beautifully white,” explained Berglund. “But because wood isn’t naturally transparent, we achieve that effect with some nanoscale tailoring.”

To allow light to pass through the wood more directly, the team incorporated a transparent polymer, often known as Plexiglass.

KTH Royal Institute of Technology

Lars Berglund, a professor at the Wallenberg Wood Science Center at KTH, led the study.

The researchers could not only see through the resulting material, but also maintain that it was twice as strong as Plexiglass, they reported.

Solar Potential

“No one has previously considered the possibility of creating larger transparent structures for use as solar cells and in buildings,” Berglund noted.

While the wood material isn’t as crystal clear as glass, its haziness provides a possible advantage for solar cell applications, according to the researchers. Specifically, because the material still traps some light, it could be used to boost the efficiency of these cells, the team said.

What’s Next?

The team reports that it is still working on enhancing the transparency of the material and scaling up the manufacturing process.

Also, the team seeks to work with different types of wood.

“Wood is by far the most used bio-based material in buildings,” said Berglund. “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.”

Funding for the research was provided by the Knut and Alice Wallenberg Foundation.


Tagged categories: Architecture; Building Envelope; Building facades; Building materials; Building science; Glass; North America; Research and development; Windows; Wood

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