sep 07 | The Architects Newspaper
Imitation of life
By Lisa Delgado
Since the days of Vitruvius, architects have turned to nature for inspiration, but today's designers are thinking about the way a sea sponge behaves, not just the way it looks. Biomimicry, or the imitation of nature's functions and systems, is helping push the boundaries of structure and sustainability.
There's a rising star in the architecture and design communities. She can build homes so strong, they withstand more than 2,000 times their own weight. She taught Mercedes-Benz a thing or two about making more aerodynamic cars. And in her spare time, she developed a technique for creating vibrant colors with no toxins.
So who is this superstar? You know her already--her name is Mother Nature. Time and again, she's proven herself to be a master architect and engineer. (In case you're wondering, tests have shown snail shells can support more than 2,000 times their weight, the streamlined form of the boxfish helped Mercedes-Benz build an ultrafuel-efficient car, and butterfly wings have their glorious color embedded in their structure.) We might feel humbled, but then again, nature's been at this game a lot longer than we humans, honing her designs through the process of evolution.
As scientist Janine Benyus wrote in her influential book Biomimicry: Innovation Inspired by Nature (1997), "After 3.8 billion years of research and development, failures are fossils, and what surrounds us is the secret to survival… All our inventions have already appeared in nature in a more elegant form and at less cost to the planet."
Scientists and technologists have been imitating nature for years to foster innovations in engineering. The strategy is known as "biomimicry" or "biomimetics, "meaning "imitation of life." Many architects and designers are catching on, reading Benyus' book and others on the topic, and some are giving biomimicry a try themselves.
Biomimicry can be applied at various levels: forms (biomorphism), functions, or entire ecosystems. In architecture, mimicking nature's forms is one of the oldest tricks in the book. Consciously or not, builders of primitive huts echoed the form of a skeleton, crafting simple wood frames covered by animal skins. More modern architects, too, regularly develop their designs visually inspired by organic forms: the curves, tendrils, and floral shapes of Art Nouveau, the spiny spires of Gaudí, the structural vertibrae of Calatrava.
Biomimicry gets more interesting, though, when it goes beyond form. "For us, it's asking a deeper question of how the natural world does it: not what is the form but what is the function that that form provides," says Dayna Baumeister, who helped found the Biomimicry Guild, along with Benyus. The group is devoted to biomimicry consulting, education, and research. Best of all, according to the guild, is biomimicry that echoes the workings of entire ecosystems, encompassing principles of adaptability, synergy, and efficient uses of limited resources.
While the deeper forms of biomimicry have more to offer in terms of sustainability and functionality, they're also more tricky to execute well. "It needs very careful thought," says Julian Vincent, director of the Centre for Biomimetic and Natural Technologies at the University of Bath. "When you're looking at biological systems, they tend to solve problems in very different ways from engineering systems, which is why the area is so interesting. But that means that if you're looking for an answer, you shouldn't look for it in the most obvious place." To even be able to formulate the right questions to ask and the right areas of nature to emulate, "you always need a biologist on hand," he says.
Despite its potential pitfalls, architectural biomimicry has resulted in some striking successes. The most famous example is the 1996 Eastgate building in Harare, Zimbabwe, which uses natural air conditioning modeled after the air flow in a termite mound.Designed by architect Mick Pearce with engineering by Arup, the office and retail building reportedly saved its owner $3.5 million in energy expenses in the first five years alone.
Biologically obsessed architect Eugene Tsui once designed a house in Berkeley, California, with lighweight, strong trusses modeled after seagull bone marrow and a subsurface solar heating system based on the bone and capillary structures of two dinosaurs, the stegosaurus and the dimetrodon. Grimshaw Architects covered their Waterloo International Terminal in London with glass sheets that overlap like snake scales, to better hug the structure's serpentine curves.
Some biomimetic projects in the works show promise, too, such as Skidmore, Owings & Merrill's spongelike design for the Pearl River Tower, a 71-story corporate headquarters. The design won a competition calling for sustainable design thanks to some unconventional thinking by Roger Frechette and his team in SOM's performative design group. Frechette says they turned to the sea sponge for inspiration because "we found it doing a lot of things we look to buildings to do but without mechanical energy or electricity." The squishy creatures are superbly engineered to harvest fuel from the sea: They can pump thousands of gallons of water a day, from which they draw their food. Sponges also shelter and protect a multitude of tiny inhabitants, which benefit from the flow of food-bearing water.
So what do you get when you cross a highrise with a sponge? The design for the Pearl River Tower is porous, with four holes that house wind turbines to create electricity from the strong winds that blow above the ground. Defying convention, the tower faces the wind, to better harness its energy; the holes also relieve wind pressure. The building soaks up energy from the sun as well, thanks to strategically placed photovoltaic cells. With these and other energy-saving measures such as radiant cooling, the building's energy use will be reduced by 58 to 60 percent. Frechette claims it will be by far the world's most energy-efficient supertall tower when it's completed in 2009.
In another competition-winning design, landscape architects Grant Associates of Bath, England, designed a grove of "supertrees" as part of a larger future project to develop three parks around a Singapore marina. Reaching around 100 to 180 feet high, they are tree-shaped structures that will serve as homes for orchids and ferns, and shelter the humans below from rain and sun, as real trees do. The plants grow on and through the supertrees' steel lattice skin. "Current computer analysis studies are investigating a structural design solution for the skin that reflects natural patterns of branching and cellular structures," says Andrew Grant, director of Grant Associates.
The supertrees also absorb solar energy in a way that's analogous to their organic counterparts, since they support extensive arrays of photovoltaics and solar thermal panels, he says. Canopies collect rainwater, and the structures even have irrigation and misting systems that mirror natural transpiration. At night, the trees' high-tech origins are revealed, for they transform into lanterns for the garden.
Kevin Stack, president of Syracuse, New York-based Northeast Natural Homes and Northeast Green Building Consulting, exemplifies biomimicry on the grandest scale: emulating the intricate interworkings of ecosystems. His sustainable strategies recently helped him win the state's first LEED-H Gold rating, for a residence in Skaneateles, New York.
Stack has been in the sustainable home building business for nearly 30 years, and he recently became immersed in the concepts of biomimicry through reading Benyus' book and studying at the Biomimicry Institute. He found the concepts eye-opening, especially the emphasis on studying and learning from the ecological systems of the local environment. After examining patterns of rainfall in upstate New York, he found that in an unbuilt area, 30 percent of rainfall goes into the aquifer, 30 percent is taken up by vegetation, and 40 percent evaporates. He now makes sure his buildings don't disturb those natural proportions.
Stack regards the trees that surround his construction sites as natural capital since they provide shade and oxygen and their roots help manage stormwater, so he treats them accordingly. "We actually hand-dig around their root system when we have to get close, and instead of just excavating roots out of the way, we'll bend them by hand," he explains. "If we have to cut a root, we cut it cleanly, and we apply a hormone that stimulates regrowth." Instead of using materials that would have to be shipped in, such as bamboo, he chooses local ecofriendly materials such as recycled wood from old barns and PureBond, a type of plywood made from local hardwoods using a natural, nontoxic adhesive.
When it comes to green building design, "everyone's going out, looking throughout the entire world for this special item or technology or material, but the answers are right in front of us," Stack says."You just need to pay attention."