The perfect shape.
Bionics refers to the art of basing technological applications
on natural phenomena.
Lab with a view.
Although the concept of bionics has only existed since the mid-20th century, nature has always been a source of inspiration for scientists and inventors. In 1505, Leonardo da Vinci composed his famous study, Codex on the Flight of Birds, and subsequently tried to build flying machines based on the knowledge he gained. All he lacked was the technological
means to realize his visions. Since then, researchers in various disciplines have repeatedly looked to the natural world outside their laboratory windows. Swiss engineer Georges de Mestral, for example, based his invention of Velcro in the 1940s on the hooked seeds of the burdock plant.
COPYCAT: The BionicOpter imitates
The huge dragonfly lifts gingerly off its perch, beating all four of its wings, slowly at first, then faster and faster. One could easily imagine that a prehistoric dragonfly has actually been restored to life – were it not for the hum of the servomotors. In fact, this 44-centimeter-long (17-inch) flying machine is not a living, breathing animal, but a high-tech creation made of aluminum, carbon fiber and polyamide. Constructed by Festo, an engineering firm in southwestern Germany, the artificial dragonfly is dubbed “BionicOpter” and can even fly backwards. Weighing in at just 175 grams (6 oz), the minuscule flier is controlled by – what else – a smartphone. The man-made insect’s wings can beat up to 1,200 times per second, and it boasts a repertoire of 13 different maneuvers.
“We view this project like automakers do a concept car. We want to demonstrate what is technologically possible,” explains project manager Heinrich Frontzek.
The nature is role model.
In the 1980s, Dietrich Bechert designed a specialized type of foil that imitated the hydrodynamic properties of sharkskin. Aircraft covered with this foil consume four percent less fuel than normal. The upwardly bent wingtips found on modern aircraft are also a fuel-saving measure; by minimizing turbulence, they reduce air resistance. The naturally-occurring counterpart of these winglets, which are also found on Formula 1 race cars, are the wingtips of large birds with their maneuverable feathers. Tire manufacturers have also modeled their tread profiles on natural phenomena, such as bee honeycomb or the feet of tree frogs and geckos. Mercedes-Benz also has a hand in bionics research. In 2005, the company unveiled the “bionic car”, a concept vehicle based the principles of bionics.
The car’s extremely low drag coefficient of 0.19 is a direct result of its aerodynamic shape, inspired by the tropical boxfish.
Source of inspiration.
Just how efficiently nature optimizes certain shapes via the process of evolution is clearly illustrated by a wind tunnel experiment conducted by Mercedes-Benz engineers: an anatomically accurate model of the boxfish recorded a drag coefficient of just 0.06. “Mother Nature has had millions of years to hone her designs,” is how Werner Nachtigall explains these near-perfect aerodynamics. Nachtigall is one of the world’s most renowned bionics pioneers. For over 50 years, the retired professor has been researching how and what technology can glean from biology. Through experimentation, mistakes and natural selection, forms of life emerge with characteristics that are often astounding. But the field of bionics isn’t about simply aping nature in all its detail. The key is staying faithful to the overarching principle.
Soma, a Viennese architectural firm, also employs bionics. “Nature is our main source of inspiration, especially in the conceptualization phase,” says Stefan Rutzinger, one of the company’s founders.
Beauty and functionality.
At the 2012 World Expo in South Korea, its spectacular One Ocean pavilion raised eyebrows. The high-tech structure’s organic lines and surfaces were especially impressive. But beauty – at least in terms of bionic structures – is considered a coincidental, albeit pleasing, byproduct which takes a back seat to the main goal of functionality. In addition to its biomimetic qualities, this façade also fulfills an architectonic function by controlling the influx of light and the interior temperature. The Soma team went a step further in its design for a Salzburg art pavilion: using a computer to calculate the optimal position of 1,500 aluminum struts with a random number generator, the team essentially created a time-lapse version of the natural process of evolution.
Nonetheless, Rutzinger is conscious of his inherent limitations: “We can try to approach nature’s complexity, but nature will always be more complex by a huge margin.”
The lotus effect.
Attempting to imitate nature can be fraught with difficulty, as biologist Wilhelm Barthlott learned. In the 1970s, the German professor discovered the “lotus effect”. Considered a Buddhist symbol of purity, the flower has the unique ability to self-cleanse. Examining it under an electron microscope, Barthlott discovered the reason: the surface of the flower’s petals only appears smooth to the naked eye, while in reality it is covered with microscopic waxy nubs. This covering makes water bead, taking dirt particles along with it. “It took us ten years just to acknowledge we could actually make something.” It took another decade to get a real product onto the market. Today, we have self-cleaning roof tiles, window glass and auto care products all incorporating the lotus effect. Adopting a long-term perspective is essential when working with bionics. After all, what are 20 years of intensive research compared to millions of years of evolution?