Smart facade uses air and AI to cut emissions

May 23, 2025

Scientists in Germany have unveiled a groundbreaking smart façade system that changes shape in response to weather conditions to help optimize the energy efficiency and indoor comfort of buildings, thus offering a new path toward adaptive building technologies.

Named FlectoLine, the 898-square-foot (83.5-square-meter) system underwent two years of real-world testing and was recently awarded a special prize at the inaugural “Award for Bio-Inspired Innovations Baden-Württemberg.”

The innovative technology, developed through the international research project Flectuation, is the product of more than a decade of work led by the Institute of Building Structures and Structural Design (ITKE), the Institute for Textile and Fiber Technologies (ITFT) at the University of Stuttgart, and the PBG Plant Biomechanics Group at the University of Freiburg.

Currently installed on a greenhouse at the Botanical Garden in Freiburg, the demonstrator consists of 101 flexible flaps, shading elements made from fiber-reinforced plastic laminates, that respond dynamically to environmental conditions using compressed air and artificial intelligence (AI).

First operational full-scale outdoor prototype

The researchers explained that the flaps fold together to let in as much sunlight and warmth as possible during cold weather. This results in maximum heat and sunlight entering the building’s interior. Meanwhile, when temperatures rise, the flaps open to provide shade.

Machine learning algorithms predict the optimal settings based on current and forecasted conditions, ensuring a constant balance between indoor comfort and energy efficiency. In addition, integrated photovoltaic modules power the system sustainably.

“The test system installed in Freiburg is based on over ten years of research,” Edith A. Gonzalez, MSc, an ITKE research associate, highlighted. “It is the first fully functional, large-scale outdoor demonstrator of an adaptive façade made from pliable fiber-reinforced composites.”

The team revealed they based the concept on nature, with the waterwheel plant (Aldrovanda vesiculosa) and the striped bug serving as biological models for the design.

“The waterwheel plant is a carnivorous plant that can close its traps to catch small animals such as water fleas,” Matthias Ridder, MSc, an ITFT research associate, emphasized. Inspired by this mechanism, the team turned to the striped bug to gain insight into the material structure of the shading elements.

Ridder explained how by varying stiffness across different parts of its wings, the bugcano deform them to perform highly accurate movements, a principle mirrored in the way FlectoLine’s flaps move to adjust shading.

Nature meets technology

This unique blend of biology and engineering impressed the jury at the “Award for Bio-Inspired Innovations Baden-Württemberg,” earlier this month. Organized by the Network for Bionic Developments Baden-Württemberg e.V. with support from the regional Ministry of Food, Rural Areas, and Consumer Protection, the award ceremony occurred during the 6th Bionics Congress in Mannheim.

The FlectoLine team was honored with a special MVV Foundation for the Future prize for their bio-inspired innovation.

Highlighting the significance of the recognition, Gonzalez stressed the urgent need for architecture to take new directions in response to the challenges of climate change.

“With FlectoLine, we have successfully demonstrated how much potential adaptive façades hold in this regard,” Gonzalez concluded in a press release. “FlectoLine maximizes the comfort and functionality of the building while simultaneously improving energy efficiency and reducing CO₂ emissions.”