Science is perfecting transparent wood aka how to ruin a Trojan horse

[playht_player width="100%" height="175" voice="en-AU-Wavenet-A"]

The ancient Greeks might not be in the market for it, but developments in transparent wood could change how we approach building all kinds of things.

On the face of it, transparent wood sounds like an oxymoron. We can no more see through wood than we can through bricks, but it turns out scientists have been thinking about and producing types of transparent wood for a while now. So what’s new?

By approaching the problem from a new angle, scientists have made a breakthrough that simplifies the process and is more sustainable. To appreciate just how cool this is, we need to get a little bit technical about wood.

The main component of wood that determines its colour and opacity is stuff called lignin. Lignin is super important for the cell walls of wood and bark helping to create a rigid structure. In essence, lignin is why tree trunks are hard. Sweet! Lignin is also the reason why wood is such a great structural choice for buildings (or even your humble Trojan horse). But there’s that downside that I’d never considered, but others clearly had 🙃 – lignin is also adding that sweet wooden colour that makes it impossible to see through trees.

It’s precisely because of wood’s amazing structural properties that scientists have been interested in the possibility of transparent wood since the 1990s, and it can be done. Unfortunately the early processes were both resource heavy and unsustainable because of the waste product produced. That is until now.

A team led by Qinqin Xia and Chaoji Chen working in conjunction with University of Maryland have demonstrated a new way of easily creating transparent wood with water as the main by-product.

The other potential advantage with this new break-through is that the lignin is not destroyed in the process of creating transparency. As recently as 2018 there were experiments in creating transparency focused on removing the lignin from wood and replacing it with a clear epoxy. But the new process, published in Science Advances explores a method that retains much of the lignin. The breakthrough involves bleaching the lignin using hydrogen peroxide and using ultraviolet light to achieve the transparent effect. The result is wood that is transparent and retains much of its strength. According to the paper, this new style of transparent wood has a tensile strength around fifty times greater than transparent wood that has had the lignin removed.

The Trojans probably wished they’d known about this kind of tech before the Greeks turned up on their shores. As for me, I’d be happy to see a sketch of what it would look like to see all those fierce ancient warriors jammed into a giant see-through wooden horse!