Optical Wood: A smart, sustainability-focused material for future buildings

Photo credit: TGS

Wood is a highly renewable material, capable of regenerating naturally. It leaves a smaller environmental footprint compared to other materials and generally does not generate dangerous and unsafe waste. It is crucial to balance the abundant use of steel and plastic that dominate our living environments. One of the most exciting recent inventions is Optical Wood, a material made from natural wood that can help control indoor temperatures in a more sustainable manner. 

This innovative material was presented in a study published in late 2023 by Cornell University in the United States; last revised in November 2024. It is designed to manage heat and light in buildings by either reflecting sunlight or allowing it to pass through, depending on the outside temperature and season. Optical wood could become a key tool for architects and designers who want to build greener homes and offices.

Transforming trees into tech

Optical Wood begins as regular wood but goes through a process to remove the substance that gives wood its color and strength. What remains is a white, porous material made mainly of cellulose, which is found in every plant. The result is a lightweight structure with special properties that make it useful for controlling heat and light.

This material reflects most of the sunlight and helps release heat, making it ideal for cooling buildings during warmer weather. When the material is treated with a natural liquid called phenylethanol, it turns nearly transparent, allowing sunlight to enter and warm the space—perfect for colder months.

Where Optical Wood fits in

The main potential of Optical Wood is in buildings, especially for windows, walls, and roofs. Imagine windows that can naturally help regulate the temperature indoors without turning on the heating or the air conditioning. We can find this switchable ability in other materials like glass or plastic, but typically their use serves only one function.

What makes this material more sustainable?  

What makes Optical Wood an eco-friendly choice is that it is made from renewable resources, since it is natural wood. It saves energy and uses safer “ingredients” because the liquid that switches the properties of the wood is made from plant oils, making it a biodegradable material.

From lab to building site: What’s next? 

Scaling up the production, ensuring long-term durability, and integrating the material into existing building practices are challenges that need to be addressed. However, Optical Wood is the result of natural materials and clever design. The ability to naturally heat or cool a building could make it a game changer for energy-efficient construction. Currently, it is still a prototype, but it represents an exciting step forward in how we think about building materials and eco-friendly design.

The researchers behind Optical Wood are optimistic. It could become a practical solution in the near future while attracting more investment and research into innovative materials and sustainability.