Semi-Transparent, Strong Wood Developed from Natural, Low-Cost Materials

A team of researchers at Kennesaw State University, USA, has developed a new type of semi-transparent, durable wood using inexpensive, largely natural materials. Presented by Professor Bharat Baruah at the American Chemical Society (ACS) Spring 2025 Meeting, this innovative material offers exciting possibilities as a sustainable alternative to glass and plastic in applications such as energy-efficient windows, interior elements, product packaging, and wearable sensors.

A Natural Approach to Transparent Wood
Transparent and semi-transparent wood materials have been proposed for over a decade as eco-friendly alternatives to plastics, often using synthetic polymers to fill the wood’s pores after chemical treatment. However, those methods typically rely on epoxy resins or polyvinyl alcohol (PVA) — petroleum-based materials that undermine biodegradability.

Professor Baruah’s team sought a different approach. Inspired by his own woodworking hobby and knowledge of historical construction techniques in his home region of Assam, India, he drew on ancient practices where sticky rice and egg whites were used as binding agents in masonry.

In this research, the team transformed thin slices of balsa wood by removing two of its main components: lignin and hemicellulose. These are responsible for wood’s opacity and rigidity. What remained was a porous, paper-like cellulose framework. They then filled the voids with a mixture of egg white and rice extract, along with a small quantity of a curing agent (diethylenetriamine) to stabilise the structure while maintaining semi-transparency.

This simple, natural process produced wood sheets that were sturdy, flexible and semi-transparent — without relying on synthetic plastics.

Sustainability and Design Applications
The development of this material has clear relevance for professionals in architecture, interior design, product design and packaging. The use of biobased, low-cost ingredients and an energy-efficient production method aligns with growing demand for circular, sustainable material solutions.

One practical application demonstrated by the researchers involved replacing the glass window in a model birdhouse with a panel of semi-transparent wood. When tested under a heat lamp, the birdhouse with the transparent wood window remained 5 to 6°C cooler than one fitted with glass, indicating superior thermal insulation properties.

This suggests potential for use in energy-efficient building components, such as windows and partitions that allow light to filter through while reducing heat transfer and maintaining privacy.

For product and packaging design, the material’s natural aesthetic and partial visibility offer an appealing, sustainable alternative to plastic display windows or decorative panels.

Added Functionality
To further extend its potential, the research team experimented with embedding silver nanowires in some samples, enabling the semi-transparent wood to conduct electricity. This opens possibilities for future use in wearable electronics, smart packaging, or solar technologies. The team is now exploring options to replace the silver nanowires with biodegradable conductive materials, such as graphene, to maintain full circularity.

This research illustrates how reimagining natural materials can lead to innovative, eco-friendly solutions for modern design challenges.

Source: American Chemical Society / EurekAlert!
Image: Bharat Baruah