Bio-inspired, adaptive building skins

Development of an integrated actuator system for adaptive fiber-reinforced composite structures

Biological role model shield bug (Graphosoma italicum)
Biological role model shield bug (Graphosoma italicum)

Within the project BIAG, the inner structure of insect wings – especially the shield bug Graphosoma litalicum – was examined with regard to their functional principles for hingeless motion priciples. The folding pattern of the wing is controlled by the inner, cellular structure. Basic principles, for example the layered structure of the cuticle in regions with high and low rigidity was transferred into a fiber-reinforced plastic with multi-layered structure and locally integrated hinges.

FRP hinge actuated via pneumatics
FRP hinge actuated via pneumatics

At the same time, the actuation of planar fiber-reinforced plastic elements via pneumatic actuators was investigated. This principle can be found in insect wings also: Here the movements are controlled by hemolymph.

The operating principle of local hinges and integrated actuators is shown by the demonstrator of the project, Flexafold.

The video shows the development process of the façade shading system Flexafold from the biological analysis to abstraction and simulation as well as the technical material investigation and implementation of the findings in a demonstrator. Material and actuation principle were awarded the MATERIALICA Gold Award 2018. The Flexafold demonstrator is characterised by 10 pneumatic chambers integrated in the fiber reinforced plastic, which simultaneously control the movement.

Demonstrator of project BIAG – Flexafold


Project duration

January 2015 – December 2017

Project team

ITFT Institute for Textile and Fiber Technologies, University of Stuttgart
Prof. Dr.-Ing. Götz T. Gresser, Larissa Born

ITKE Institute for Building Structures and Structural Design, University of Stuttgart
Prof. Dr.-Ing. Jan Knippers, Axel Körner, Anja Mader, Gundula Schieber

EvE Evolutionary Biology of Invertebrates, Institute of Evolution and Ecology, University of Tübingen
Prof. Dr. Oliver Betz, Paavo Bergmann

DITF German Institutes for Textile and Fiber Research, Denkendorf
Prof. Dr.-Ing. Markus Milwich, Lena Müller

Associated partners

Transsolar Energietechnik GmbH
HZ Hachtel GmbH & Co. KG
S-form Kunststofftechnik
Global Safety Textiles GmbH
Studio 2050
Knippers Helbig GmbH


This research has been funded by the Baden-Württemberg Foundation / project BIAG.

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