FlectoLine: Façades in motion

FlectoLine has been successfully tested under real conditions for two years. The adaptive façade is installed on a greenhouse in the Botanical Garden in Freiburg. “Adaptive” means that the system reacts in real time to environmental influences and thus helps to optimize the energy efficiency and indoor comfort of buildings. 

The 83.5 square meter FlectoLine demonstrator consists of 101 “flaps”, shading elements made of fiber-reinforced plastic laminates. Each flap is equipped with flexible hinges and can bend elastically with the help of compressed air: In cold weather, the flaps fold together so that as much light and therefore heat as possible penetrates into the interior of the building. In hot weather, they unfold to provide shade. The system's controller uses machine learning to predict optimal settings for different scenarios. Integrated photovoltaic modules ensure sustainable operation.

FlectoLine was developed as part of the international research project “Flectuation”.  The Institute of Building Structures and Structural Design (ITKE) and the Institute for Textile and Fiber Technologies (ITFT) at the University of Stuttgart and the PBG Plant Biomechanics Group at the University of Freiburg were involved.  “The test system installed in Freiburg is based on over ten years of research. It is the first fully functional, large-scale outdoor demonstrator of an adaptive façade made from pliable fiber-reinforced composites," says Edith A. Gonzalez, research associate at the ITKE.

The researchers drew their inspiration for FlectoLine from nature. The waterwheel plant and the striped bug served as models. “The waterwheel plant is a carnivorous plant that can close its traps to catch small animals such as water fleas. We were inspired by this mechanism. The striped bug provided insights into the material structure of the shading elements: by varying stiffness across different wing areas, it can precisely deform its wings to perform highly accurate movements - just like the shading elements of FlectoLine,” says Matthias Ridder, research associate at ITFT.

For their clever, nature-inspired innovation, the researchers were honored in May 2025 at the "Award for Bio-Inspired Innovations Baden-Württemberg." This year saw the inaugural presentation of the award, organized by the Network for Bionic Developments Baden-Württemberg e.V., with support from the Baden-Württemberg Ministry of Food, Rural Areas, and Consumer Protection. The formal ceremony was held during the 6th Bionics Congress Baden-Württemberg in Mannheim.

The FlectoLine team was honored to receive the special prize from the MVV Foundation for the Future for their bionic/bio-inspired innovation. “We are very proud of this recognition," says Edith A. Gonzalez. “In light of the challenges posed by climate change, architecture must take new directions. With FlectoLine, we have successfully demonstrated how much potential adaptive façades hold in this regard.  FlectoLine maximizes the comfort and functionality of the building while simultaneously improving energy efficiency and reducing CO₂ emissions.”