engadget reports: [edited]
Researchers at the University of Maryland were able pull away colour and chemicals from a block of wood. The result is a material that is both stronger and more insulating than glass, with better biodegradability than plastic. "We were surprised how transparent it could go," said Liangbing Hu, who wrote about the project in Advanced Materials.
Hu's team isn't the only group that's developed a technique for transparent wood - Swedish researchers have also been able to clear out the visible pulp, replacing it with a transparent polymer. The treatment techniques appear similar.
The researchers first boil the wood in water, sodium hydroxide and other chemicals for roughly two hours. This flushes out lignin, the molecule responsible for giving wood its colour. The team then pours epoxy over the block which makes the wood four to five times stronger.