Plopp stool, finished form, can hold an astounding 2.5 tons

Architect Oskar Zieta, with inflatable metal

Over the centuries, we’ve welded metal, beat it into shape, bent it, melted it. But until recently, we’ve never inflated. Now that too is possible, thanks to years of painstaking work by architect Oskar Zieta and materials scientist Philipp Dohmen, both researchers at Zurich’s ETH (better known as Einstein’s alma mater).

The two call their work Free Internal Pressure Reshaping–FIDU, for short. But the process might seem familiar to anyone who’s ever blown up an inflatable raft. Zieta and Dohmen are exhibiting their process–and its promises–at next week’s DMY Berlin International Design Festival, which celebrates cutting-edge design. But if you can’t make it, here’s a taste.

ChippenSteel chair

Thin sheet metal is welded together along seams…

The finished products bear a resemblance to Jeff Koons’s huge sculptures of inflatable toys. But Zieta and Dohmen have invented a high-tech process all their own. First conceived of five years ago, it begins simply with thin sheet metal that’s been welded together along seams, akin to the way plastic sheets are fused for blow-up toys…

Zieta (left) and Dohmen

The fabrication begins with a guide shape, in which two layers of metal sheets are laid and then welded.

…then, the metal can be inflated with tubes spitting out high-pressure air.

...then, the metal can be inflated with tubes spitting out high-pressure air.

The welded sheets can be flat packed and shipped 100 to the palette, and inflated by a middleman closer to their final destination.


The metal is then bent into shape. When finished, they’re remarkably strong:

Plopp stool, unfinished form

The Plopp stool can hold an astounding 2.5 tons, despite being light enough to lift with a finger. Architect Oskar Zieta, with inflatable metal

Armed with new, more complex welding machines and bigger equipment, the duo has begun expanding to a range of projects.metal installation

The designers soon hope to apply their method to full-blown architectural structures. Installation detail

How to Make an Inflatable Metal Chair | Slideshows.