Normally used as a hydrogel in biomedical applications, nanocellulose can also be a sustainable alternative architectural material.
The construction industry faces a dilemma: there is a growing need for more housing in many parts of the world but building that housing consumes substantial fossil fuel resources and generates a significant amount of carbon dioxide.
Demand and sustainability are pulling against each other, but thanks to some research at Chalmers University of Technology in Sweden, that tug-of-war could soon become less vicious. A team of architects, engineers and scientists have devised a way to 3D print nanocellulose hydrogel into an architectural material, opening the door to a host of sustainable applications.
“For the first time we have explored an architectural application of nanocellulose hydrogel,” explained associate professor of architectural design, Malgorzata Zboinska, in a press release. “Specifically, we provided the missing knowledge on its design-related features and showcased—with the help of our samples and prototypes—the tuneability of these features through custom digital design and robotic 3D printing.”
While nanocellulose hydrogels have been successfully 3D printed into scaffolds for tissue growth in biomedical applications, this is the first time they have been used for architectural design. Besides nanocellulose and water, the secret ingredient to the research team’s feedstock is alginate, an algae-based material that adds flexibility to the material once it dries.
The principal advantage of this approach is the abundance of materials, which can be acquired from forestry, agriculture, paper mills and straw residues from agriculture. The process doesn’t use dies or casting forms and the room-temperature pneumatic 3D printing process is more energy efficient.
The process does not require heat due to the shear thinning properties of nanocellulose hydrogel. Applying air pressure causes it to liquify and become printable. Once the pressure is removed, the workpiece retains its shape.
According to the researchers, the dried shapes can be applied as a basis to design a wide array of architectural standalone components, such as lightweight room dividers, blinds, and wall panel systems. They could also form the basis for coatings for tiles, acoustic elements for damping sound, and combined with other materials to clad skeleton walls.
The lingering question with this technology is how long will components made from nanocellulose last. According to Zboinska, this is the essential question for organic construction materials.
“Traditional building materials are designed to last for hundreds of years. Usually, they have predictable behaviours and homogenous properties. We have concrete, glass and all kinds of hard materials that endure and we know how they will age over time.
“Contrary to this, biobased materials contain organic matter, that is from the outset designed to biodegrade and cycle back into nature. We, therefore, need to acquire completely new knowledge on how we could apply them in architecture, and how we could embrace their shorter life cycle loops and heterogenous behaviour patterns, resembling more those found in nature rather than in an artificial and fully controlled environment.”
The research is published in the journal Materials and Design.