Solar Gate: The First 4D-Printed Adaptive Façade System

Indoor comfort generally requires a high energy input, which means that buildings account for a significant proportion of global carbon emissions. In 2020, for example, single-family homes consumed an average of 864 petajoules of heating energy, an enormously high figure. Researchers at the Universities of Stuttgart and Freiburg have now developed a promising solution to reduce this energy requirement for heating and cooling: a self-sufficient façade system that adapts independently to changes in the weather thanks to 4D printing. What’s more, the project is biomimetic, which means it was inspired by nature.

Solar Gate is the world’s first adaptive shading system that works depending on the weather and does not require energy from an electrical drive. The pine cone, whose scales open and close in response to changes in humidity or temperature without consuming metabolic energy, served as a model. Based on this principle, the team reproduced the direction-dependent structure of cellulose in plant tissue using 3D printers.

Thanks to bio-inspired 4D printing and cellulose materials made from renewable raw materials, the team has developed a system that automatically adapts to changes in the weather. (Photo credit: ICD/IntCDC University of Stuttgart)

“Weather-responsive architectural façade systems usually rely on complex technical devices. Our research investigates how we can harness the responsiveness of the material itself through computer-based design methods and additive manufacturing. We have developed a shading system that opens and closes independently depending on weather conditions, without the need for any operating energy or mechatronic elements. The biomaterial structure itself is the machine,” explains Professor Achim Menges, Head of the Institute for Computer-Based Design and Construction and spokesperson for the Cluster of Excellence Integrative Computer-Based Design and Construction for Architecture at the University of Stuttgart.