New ways of naturally bending wood are all about curve appeal

It normally takes an enormous amount of energy and heavy machinery to shape wood. Now, scientists have discovered a way of bending wood naturally: using digital tools that precisely define the shape in advance. This gives architects completely new, more sustainable outlooks for the future.

The Urbach Tower is situated on a small hill, surrounded by fields and vineyards in southwest Germany. Built as part of a horticultural show in 2019, the distinctive structure is a local landmark. The tower is also a manifesto for the future of architecture. Its curved wood facade is a paradigm shift in timber manufacturing. Instead of using elaborate wood-bending processes, the designers relied on natural forces to trigger the wood to more sustainably twist itself into shape with material programming.

The tower is the brainchild of two experts in the field: Dylan Wood, who leads the material-programming research team from the Institute for Computational Design and Construction (ICD) at the University of Stuttgart, and Markus Rüggeberg, from the Cellulose and Wood Materials Laboratory at Switzerland’s EMPA research institute, which created several wood projects as part of the innovative NEST building experiment in Zurich.

“Timber is a very sustainable material,” Wood says. “And it’s even more effective when it’s curved rather than straight.” Thanks to material programming, researchers have ensured wood can be made further attractive as a sustainable solution.

To understand how material programming works, it’s important to start with the concept that, just as machines can be programmed to move in certain ways, wood can be “programmed” to deform in certain directions during the drying process. Computer simulations allow architects to preview wood deformations. This lets them know exactly how much material and moisture is required to achieve a certain shape.

The shaping process can begin once data such as desired material thickness and moisture content are calculated for a design. First, a thin dry layer of wood is glued on top of a thick, moist layer of wood, with their grains running at perpendicular angles. This process stabilizes the component so that when moisture is lost while drying, the wood shapes itself to the precise geometry that was previously determined by the computer-based process. Once the drying process is complete, the wood remains curved.

The team is already developing new methods for self-shaping larger building components, like roof panels, directly on site. They’ve even recently unveiled a concept for flat-pack furniture that shapes itself at home with no assembly, tools, or instructions required.

“The beauty of these types of processes is that the digital tools allow us to embed shape directly into the materials of a component in the factory,” Wood says. “This could dramatically reduce the need for on-site machinery and the ecological impact of construction. It’s a cleaner and quieter method of building that could be widely distributed for projects where it’s too expensive to send out a team of workers or equipment. Instead, we direct the materials to do the complex heavy lifting.

“The best part is that here we can achieve this simply by understanding and directing a natural material. The researchers envision the concept as an ideal example of Industry 4.0: a highly flexible, adaptable manufacturing process based on the digitization, sorting, and arranging of natural materials to shape different geometries and products.”