Three decades ago, German botanist Siegfried Fink pioneered a revolutionary concept: creating transparent wood by bleaching plant cells. His breakthrough technique, published in a 1992 wood technology journal, remained dormant until materials scientist Lars Berglund stumbled upon it, sparking a renewed interest in transparent wood. Collaborating with researchers at the University of Maryland, Berglund and his counterparts at KTH Royal Institute of Technology in Sweden have now harnessed the potential of transparent wood for various applications.

Wood’s intricate structure consists of vertical channels resembling bundled straws held together by glue called lignin. To achieve transparency, researchers remove or modify lignin, leaving a milky-white skeleton of hollow cells. By filling these cells with a substance like epoxy resin that bends light similarly to cell walls, transparent wood is created. Despite its thin profile, transparent wood exhibits remarkable strength, outperforming plastic and glass in fracture and pressure tests.

The material’s potential applications include super-strong screens for smartphones, soft, glowing light fixtures, and structural features like color-changing windows. Transparent wood’s insulating properties make it an excellent alternative to glass in architectural settings, providing enhanced temperature control. Researchers have also explored modifying transparent wood’s ability to hold or release heat, making it suitable for energy-efficient buildings.

Recent developments focus on sustainability, with efforts to replace petroleum-derived plastic resin with bio-based alternatives. One such innovation involves a fully bio-based polymer derived from citrus peels, maintaining mechanical and optical properties. Greener lignin-bleaching methods, using hydrogen peroxide and UV radiation, further reduce the environmental impact. However, scaling up production and embracing eco-friendly practices are essential steps before transparent wood becomes a mainstream material.

While challenges remain, researchers are optimistic about transparent wood’s potential as a sustainable material, transcending the properties of traditional fossil-based materials. Emphasizing the importance of surpassing existing standards, scientists envision a future where transparent wood becomes a key player in environmentally friendly manufacturing processes.

By Impact Lab