Rolf Luchsinger

Empa - Center for Synergetic Structures, Dübendorf, Switzerland

Use the air!

Summary

Pneumatic structures have interesting features such as the low weight, the compact transport volume and the fast and easy set up. They have found applications e.g. as inflatable boats, hot air balloons or air houses. On the other hand, major drawbacks of pneumatic structures are the limited shapes, the very limited load bearing capacity as well as the vulnerability. Major progress was made for all these problems in recent years enhancing considerably the range of possible applications of pneumatic structures. The Swiss company prospective concepts has built a series of demonstrators from the manned inflated airplane Stingray to inflated boats with the form of a traditional wooden boat proving that shapes beyond spheres and cylinders can be realized, too.

The new structural concept Tensairity® solves the load bearing problem by combining the pneumatic structure with a cable-strut structure in a synergetic way. A Tensairity roof with 28m span as well as skier bridge with 52m span demonstrate the feasibility of the new light weight structural concept. The R&D of Tensairity is performed at the Center for Synergetic Structures, a public private partnership between Empa and Festo/prospective concepts. Our work focuses on the detailed understanding of the structural behavior of Tensairity and seeks new applications next to civil engineering. We have recently built and tested a Tensairity kite with 8m span which might lead to a new technology for wind energy harvesting. The Tensairity actuator is a new concept to generate mechanical work and can be interesting in robotics. And finally, the vulnerability is addressed by a bionics project, where we develop self-repairing membranes for pneumatic structures by mimicking the healing mechanisms in plants.