Car design: technology inspired by nature

Klaus Millerferli holds in his hands the shock absorber cup of the new Mercedes EQXX. The metal part, with no defined shape or structure, looks more like a garbage can than an avant-garde component. Seeing it, you can hardly believe that it is intended to serve as a support for the front axle of the sophisticated electric model.

However, the head of the Vision EQXX concept cradles the casting in his hand with the utmost appreciation and is pleased with its low weight and aerodynamic shape. Because it is not only extremely stable, but also weighs four kilos less than a conventional component.

“We have built it taking nature as a model,” says the engineer. It did not emerge from a drawing board, but was developed with the same software that is used to generate the monsters of computer games. It wasn't drawn, the piece has been growing like a skeleton. The component is extremely stable at crucial points, but does not need excess material anywhere and is therefore particularly light, according to the expert.

Millerferli thus follows a trend that is currently very popular among car developers. In the struggle for the least possible weight and maximum autonomy, they are inspired by nature. This approach is especially evident in the Mission R concept, with which Porsche is shaping the electric racing car of the future.

Instead of building a frame and then covering it with a body, the two-seater has a carbon skeleton with transparent segments that allow very unusual views inward and outward, especially on the roof. This so-called exoskeleton is not only particularly light and stable, but also looks spectacular, says designer Peter Varga.

Even before Porsche, the German company EDAG presented the Genesis prototype in 2014, with a completely 3D printed body inspired by the biology of a turtle shell.

The two-seater sports car of the Fraunhofer Institute for Manufacturing Engineering and Automation (IPA), based in the German city of Stuttgart, is another example. To ensure that it really stays below 500 kilos and still offers sufficient protection against accidents, the body of the model was inspired by the skull of the marine reptile “Simosaurus”.

In addition to lightweight construction and safety, it is above all aerodynamics that is inspired by nature. “Because when it comes to air resistance, evolution has already produced some sensational forms,” says Teddy Woll, head of the wind tunnel of the German Daimler consortium.

However, there are also limits, especially in the conflict between aerodynamics and aesthetics, Woll admits, and alludes to the boxfish, which became a model for the bionic car presented by Mercedes in 2005.

With a drag coefficient of Cw 0,19, the fish is particularly aerodynamic and the model inspired by it is incredibly efficient. However, its form was unlikely to appeal to the general public. The experimental prototype was long ago discarded from the designers' halls.

As new as these ideas are, bionics is something old. Whether it's cars, aviation or household appliances, nature has served as a model for practical advances since time immemorial.

One of the most popular examples of the transfer of nature to the factory is the so-called lotus flower effect, with which the leaves of the plant are protected from dirt. Making use of this property, paint manufacturers will soon make car washes superfluous and tire manufacturers want to keep the sidewalls of their tires clean.

But it's not just flowers that inspire researchers. Years ago, engineers at Bavarian BMW closely examined the skin of the shark. It has special profiles that reduce frictional resistance by up to three percent. The idea: if these profiles are transferred to a sheet and glued to the sheet metal, fuel consumption could also be reduced.

The manufacturer ended up abandoning the idea, but continues to seek solutions to new technological challenges in other sectors, including bionics: “Bionics is a source of inspiration and offers possible solutions,” says Julia Jung, BMW spokesperson.

dpa