Bone Chair

My fascination with the digital era really took off when I saw an animation in a documentary about German Professor Claus Mattheck. To me this was not just an animation of an optimized engine mount, but a visualization of how the industrial era in general is transforming into the digital era. Industrial times and modernist pioneers were all about assembly and standardized parts in a geometric form language dictated by the limitations of industrial machines.

In our digital era, however, we are no longer bound by these limitations. With digital design and fabrication tools we can create smarter customized forms that are much more complex. But it is also true that throughout design history, designers have striven to make objects inspired by nature: from Art Nouveau, driven by innovations in materials like cast iron, to Streamline, driven by innovations in materials like aluminum, and the organic design of the 1960s, driven by innovations in plastics and plywood. But our digital age makes it possible to not just use nature as a stylistic reference, but to actually use the underlying principles to generate shapes just like an evolutionary process.

While trees have the ability to add material where strength is needed, bones have the ability to take away material where it is not. With this knowledge, German engineer Professor Lothar Harzheim, together with the International Development Centre Adam Opel GmbH, developed a dynamic digital tool that copies these ways of constructing, and used it to optimize car parts. This software mimics quite precisely the way evolution constructs. For me, this opened up an entire world of possibilities that we can only begin to imagine.

The design of the Bone Chair actually began back in 1998, when Adam Opel GmbH, a German General Motors subsidiary, developed new imaging and simulation software with the intention to create a more efficient engine mount. The purpose of the engine mount design software was to fix specific elements in place while providing optimum strength, using a minimum of materials. This is done by creating a virtual three-dimensional model and simulating the application of stress to specific points on the design. Then the algorithm takes away all of the material that isn’t necessarily needed, without weakening the part.

What most amazed me about this process is that it uses the very same principle that evolution does in living organisms. Bones in particular are highly efficient in growing internal structures to achieve an optimal weight-strength ratio as they constantly add and remove material in response to stresses from their environment. The software designed by Adam Opel GmbH replicates the same process: repeated generations of the simulation add material where strength is needed, and chip away material everywhere it is not, creating a design that achieves maximum strength with a minimum amount of material.

When I was asked to participate in the Smart Deco exhibition initiated by Droog and Barry Friedman, my proposal was to create an entire chair by using this algorithm as a high-tech digital sculpting tool. If Mother Nature wanted to create a chair, it would probably look something like the results we would get.

For the aluminum Bone Chair, the computer-generated result had to be refined for the specifications of aluminum. This resulted in a much more slender shape. We did face yet another challenge, however, for it wasn’t going to be easy to produce such a complex organic shape. Especially because assembling it from cast components would leave visible welding stains. Preferably, it would have to be cast in one piece in such a way that no bubbles would show on the surface. Virtually every company we approached refused to take up the challenge, until we appealed to Phil Verdult, who had a small workshop somewhere in the small town of Heerhugowaard. Phil had years of experience with casting processes and had conducted many experiments with new techniques in his workshop, for instance with casting metal in 3D printed ceramic molds. The complex mold could be assembled from such mold parts, and the actual object cast in one go. This resulted in the first aluminum Bone Chair.

(photocredit: Daniel Nicolas, CAB Burgos, JL)