The sand dollar is an unlikely architectural muse. It is hard, often misshapen, and relatively flat, all of which makes it just about the last thing you’d model a building after. Yet designers and engineers at the University of Stuttgart did exactly that, and insist the burrowing sea urchins offer a compelling model for fabrication and construction.

Each year, Achim Menges, who leads the Institute of Computational Design, and Jay Knippers who leads the university’s Institute of Building Structures and Structural Design, work with their teams to draw on the natural world while exploring novel techniques which they apply to a temporary pavilion that pushes the boundaries of their craft. Last year they cribbed from the diving bell spider; the year before that, a flying beetle.

This year, the sand dollar inspired them. The designers worked with colleagues at the university’s Institute of Building Structures and Structural Design and biologists from the University of Tübingen in Germany, to create a remarkable undulating pavilion fashioned from with 151 wood panels stitched together like cloth.

The work started with a detailed examination of sand dollar anatomy. It’s a surprisingly robust organism. Crack one open and you’ll find a double-layered skeleton. Fibrous membranes bind individual plates together, creating a stiff yet flexible shell. Menges and his team mimicked this with plywood, which is stiff yet relatively easily bent into complex shapes.

Each of the 151 segments is made of three sheets of beech plywood layered to create a veneer effect. This typically requires a mold, some glue, and a lot of pressure to retain the shape, but here the team bent the wood and stitched it together with a robot. “This freezes it into shape,” Menges says. Using stitches instead of, say, screws makes the structure more resilient to the expansion and contraction that comes with changes in temperature or humidity.

Jagged edges allow each section to handle shear forces, while fibrous lacing lets everything keep its shape under tensile loads. “This is exactly how it works in a sand dollar,” he says. The wood sections are just 3 to 6 millimeters thick, but double-layered looping maximizes strength. This is perhaps the most important aspect of the pavilion, as it allows the wood components to be resilient without using much material. “It’s an incredibly materially efficient construction technique,” Menges says. Much like a sand dollar, every curved unit is slightly different. The space between the two layers varies—the larger the cavity, the more stable the component, which allows the pavilion’s shape to be optimized.

So far the technique works best with a temporary structure, but Menges says it could easily work with a permanent building—if you added a “skin” to keep everything dry. Preferably transparent, so as not to hide that beautiful honeycomb-like pattern.

Originally from – 

This Trippy Looking Building Is Modeled After a Sand Dollar