Transparent wood could soon make its way into touch screens, skyscraper windows, and car dashboards.
Thirty years ago, a botanist in Germany had a simple wish: to see the inner workings of woody plants without dissecting them. By bleaching away the pigments in plant cells, Siegfried Fink managed to create transparent wood, and he published his technique in a niche wood-technology journal. The 1992 paper remained the last word on see-through wood for more than a decade, until a researcher named Lars Berglund stumbled across it.
Berglund was inspired by Fink’s discovery, but not for botanical reasons. The materials scientist, who works at KTH Royal Institute of Technology, in Sweden, specializes in polymer composites and was interested in creating a more robust alternative to transparent plastic. And he wasn’t the only one interested in wood’s virtues. Across the ocean, researchers at the University of Maryland were busy on a related goal: harnessing the strength of wood for nontraditional purposes.
Now, after years of experiments, the research of these groups is starting to bear fruit. Transparent wood could soon find uses in super-strong screens for smartphones; in soft, glowing light fixtures; and even as structural features, such as color-changing windows.
“I truly believe this material has a promising future,” says Qiliang Fu, a wood nanotechnologist at Nanjing Forestry University, in China, who worked in Berglund’s lab as a graduate student.
Wood is partially made up of countless little vertical channels, like a tight bundle of straws bound together with glue. These tube-shaped cells transport water and nutrients throughout a tree, and when the tree is harvested and the moisture evaporates, pockets of air are left behind.
