A Cantilever Pointing to the Future

Previously we featured a couple ICD/ITKE collaborations that also involved carbon fiber structures: the Research Pavilion 2014-15, which was based on the nests of underwater spiders; and the Elytra Filament Pavilion, which used flying beetles for inspiration. The ICD/ITKE Research Pavilion 2016-17 likewise looks to nature, specifically two species of leaf miner moths – Lyonetia clerkella and Leucoptera erythrinella – that spin silk "hammocks" stretched between connection points on a bent leaf.

Under Achim Menges at ICD and Jan Knippers at ITKE, the project aimed to discover a fiber winding technique that could span a large distance without the need for much formwork. (The 2014-15 pavilion's shell, for instance, required a pneumatic formwork.) The two moth species, discovered in cooperation with the Institute of Evolution and Ecology and the department for Paleobiology of the University of Tübingen, provided principles that could be applied to the project's goals. Through biomimetic investigation, several ideas were taken from studying the moths and applied to the project's fabrication and structure: "the combination of a bending-active substructure and coreless wound fiber reinforcement to create an integrated composite winding frame, fiber orientation and hierarchy over a long span structure, and multi-stage volumetric fiber laying processes for the generation of complex three dimensional geometries," as described by ICD/ITKE.

Biomimicry may have influenced the pavilion's design, but when it came time to fabricate the 12-meter-long construction the team focused on robotic systems. Having used industrial robotic arms for fiber laying on previous pavilions, Menges and Knippers understood their strengths and weaknesses. Respectively, the robots are strong and precise, but they are limited in movement, making them insufficient for longspan structures. To overcome this, they paired two robotic arms with a custom-built unmanned aerial vehicle (UAV, aka a drone).

The off-site fabrication consisted of four main elements: two industrial robot arms placed at the ends of the structure (the cantilevered end propped up by minimal formwork), the autonomous UAV passing the fiber from one side to the other, and a tension control mechanism that responded to the UAV and robots. Further, a couple armatures and an integrated sensor interface enabled the robots and UAV to interact, passing the fiber back and forth. (The video below illustrates the fabrication process very well.) ICD/ITKE is hoping these elements lay the foundation for further explorations of what they describe as "novel multi-machine, cyber-physical fabrication processes for large scale fiber composite production."

The pavilion may have surpassed its 12-meter length if it were fabricated on site, but given the off-site fabrication the lightweight structure had to be sized for transport – all in one go given the wound-fiber construction. Nevertheless, the latest ICD/ITKE creation is an impressive one, like something from a not-too-distant future, when nature is the model and technology is the tool for shaping our environment.