1. Skip to content
  2. Skip to main menu
  3. Skip to more DW sites

Inflatable steel

September 15, 2011

The Swiss, Polish architects behind the idea say their technique can reduce construction costs. They hope to expand what began as an artistic project into more practical applications.

https://p.dw.com/p/12ZdA
Inflated steel chair
This inflated steel chair costs around 250 eurosImage: Zieta Design

For the past few years, a two-man team from Poland and Switzerland have come up with a new system of making steel cheaper and lighter, but no less sturdy - by filling it with air. Oskar Zieta and Phillipp Dohmen have pioneered what they're calling "Free Inner Pressure Deformation," a new engineering technique that allows them to make furniture -- which they've been selling since 2009. Zieta Prozessdesign sells inflated steel furniture, including ladders, chairs and stools, for 200 to 300 euros ($275 - $415). However, more recently, they have been expanding this technique that may eventually have an impact on everything from wind turbines to highway guard rails. To learn more, Deutsche Welle spoke with Phillipp Dohmen, a materials scientist at the Swiss Federal Institute of Technology, Zurich.

Deutsche Welle: So you have two sheets of steel, and you're pumping air in between them?

Phillipp Dohmen: Yes. They're cut with a laser, which is a very precise [method] of production. It's up to 0.1 millimeters. It's a very precise way to cut a metal sheet. And then we use a robot to do the welding. And then we inflate the space in between and we get quite precise elements, with plus or minus one millimeter [of error]. The nice thing is that anything can look totally different. We have a unique forming method, [and so each item is unique].

Is the idea to make it possible for people to inflate their own furniture? Now we have this IKEA-style where people buy furniture in a flat pack. Do you imagine a day when people can buy your furniture and pump it up at home?

It could be possible. Right now, Oscar Zieta is introducing this stool, this three-legged chair. Right now he's producing them and blowing them up at the factory. But when you think about transporting 100 inflated stools through Europe, it would take up a whole truck.

Phillipp Dohmen
Phillipp Dohmen (right) hopes that this technique could become more and more widespreadImage: Alexandra von Ascheraden

If you send them flat, then it's just one huge parcel that could easily be sent abroad and be blown up at that point. All you need is a little bit of air pressure. You could do it with a bicycle pump.

This technique that you've developed, has the technique changed at all over the past few years?

We are still doing research on it. Until now we've always been using steel as a material because it's cheap and common and even with this really cheap material – it's noted for its ability to take a load, rather than its weight. We've been working on different materials like aluminum and copper. Aluminum is interesting because it's hard to form when it's cold, but we've been able to do it. We even made a stool that was so light it could be lifted by a helium-filled balloon.

Do you see this going anywhere besides furniture?

Of course, as architects, we want to go back [to buildings] -- we're looking for applications in housing and construction. We've built a small bridge, even. We also made a small wind turbine. For the wind turbine, they're now made of carbon-fiber or plexiglass. They're usually made with three blades and each two-meter blade costs about 600 euros. Ours cost about 25 euros and are lighter and more durable.

Wind turbines
Dohmen hopes that inflatable steel can be used to reduce the cost of wind turbinesImage: picture alliance / dpa

Do you have any more definitive projects coming up?

We are developing a crash beam to prevent cars from going off the highway. These elements are done right now with six or seven millimeters of steel. They take the energy of the cars by deforming - 99 percent of the time you don't need them. You just need it when you run into them. We want to reduce the thickness of the materials and scale it down to two times one millimeter, and make a blown-up element.

This saves a lot of material and each kilo of steel produced means a reduced amount of 1.5 kilograms (3.3 pounds) of carbon dioxide, and [so that reduces the environmental footprint]. So we have a light element, which is stiff just because of its form. It can start deforming really easily because it's so thin.

But to increase the capability, when a bigger car runs into it, we would like to make it like an airbag. We'll put air pressure inside. Normally when our structures are finished, we release the pressure. But if you put pressure in there - about 0.5 bars - which means that five tons per square meter are pressing against it and making it stiff, it prevents the collapse.

By putting something like an airbag inside, which can detect when something is moving, we can produce more pressure inside in order to make it stiff. It would be just like an airbag, but on the other side. It's like a small explosion going off [inside the guard rail].

Interview: Cyrus Farivar
Editor: Zulfikar Abbany