Designers - architect Oscar Zieta and material scientist at the Swiss Federal Institute of Technology Philippe Domen - created the engineering method as a way to make steel products lighter and less expensive without compromising strength.
This technology, called free internal pressure deformation (FiDU), requires laser cutting of steel sheets that are precisely shaped with an accuracy of plus or minus 0.1 mm. These 1mm thick high-strength steel sheets are then robot welded for maximum manufacturing precision.
<! --dle_media_begin: https://youtu.be/KawnPODCvfw-->
This concept was initially tested in furniture production and Zieta Prozessdesign already offers a range of inflatable steel stairs, chairs and stools in the public domain.
The Plopp three-legged stools, designed by Zieta, are produced in rolled tubes from thin sheet steel. They can then be inflated using a simple valve to create a durable, lightweight and stylish seat. Thanks to the inherent strength of steel and the innovative FiDU technology, the award-winning Plopp chair can handle over two tons.
Since the compressed air pressure only needs to be 0.1-50 bar, furniture made using this method can even be inflated with a bicycle pump. Unlike existing hydroforming methods used in the automotive sector, FiDU does not rely on a mold to shape steel during inflation, so it can even be done at home.
This means that the metal will deform as it inflates according to its natural characteristics, making the individual contours of each piece unique, even if they all have the same design.
While the concept of flat furniture has changed the face of interior shopping forever, the FiDU method offers even more convenience at a low weight. Transporting even flat packing furniture takes up a lot of space, but Plopp's non-inflated stools take up almost no space compared to fully formed pieces. This translates into significant reductions in transport-related costs and emissions.
The inventors say the steel choice was based on a number of factors. Durability was key, but availability and cost were also important. The development team experimented with other materials, but the flexibility of steel meant it could be cold formed easily, unlike aluminum.
Designers see the possibilities of inflatable steel going far beyond furniture. Thanks to the team's expertise in architecture, their research is focused on industrial and residential construction, and they have been successful in building a small bridge using an inflatable steel structure.
The design team also designed and built a small wind turbine. They point out that many modern wind turbine blades are made of plexiglass or carbon fiber, with each two-meter blade costing 600 euros. The steel blades, made using the inflated steel structure, cost only 25 euros and are much more durable. The use of steel technologies here could significantly reduce the cost of using renewable wind energy sources.
Today, the team is developing a protective barrier that will run along the highway. Unlike other applications, they will be pressurized so they provide the same deformation as existing barriers, helping to absorb shock and keep drivers safe.
It is clear that this technology, based on the plastic properties of steel, can be used almost everywhere. Indeed, the inventor Zieta dreams of using FiDU for construction in space, where its ultra-light and compact design will make it unique.