|April 20, 2016|
Cities that steal smart ideas from plants and animals
|With soaring glass skyscrapers and swaths of concrete, modern cities often seem actively to work against nature, pushing it down and suppressing it rather than working alongside it.|
Yet a growing number of progressive architects, designers, engineers, scientists and urban planners are looking to the Earth's systems for inspiration.
Biomimicry is based on the idea that animals, plants and the Earth's natural processes are the ultimate engineering feats. The approach looks to replicate nature's clever ideas, whether it be designing a water collection device with inkjet-printed microdroplets imbued with binding agents, based on the Namib desert beetle's ability to harvest vapour from fog; or a passively cooled building in the style of a termite mound. Biomimicry stems from the logical conclusion that nature's systems function well: examples of when they fail are found only in the fossil record.
Of course, there is a big gap between marvelling at a spider's ability to spin a web, and designing a fabric that mimics its selectively sticky properties. And the sheltering tree does not provide the solid cover of a roof to keep out rain. But the glimpses of light and moving shadow the tree casts could offer other benefits, such as negating the need for illumination at specific times of day. A smart building might exploit these.
Dr Cheryl Desha was a panellist at last month's event Catching up with the Jetsons: Cities in 2050 at the World Science festival in Brisbane. The Queensland University of Technology lecturer in sustainable development foresees a future in which cities are more like natural environments, functional and resilient, protecting inhabitants from weather, pollution and viruses, while minimising their carbon footprint.
But there is a long way to go. "Technology is improving, but nature is ahead of us. Kilometres underwater there are organisms that, without even solar energy, are able to glow. And we are still talking about lightbulbs," she says.
Thankfully there are great minds working on it. Desha points to the not-for-profit Biomimicry Institute, founded by the eminent US natural scientist Janine Benyus.
Its website, asknature.org, is an online library of more than 1,800 bio-inspired applications for architects and engineers. The peel structure of the grapefruit--related pomelo, for example, allows it to withstand a fall of 10 metres without damage. This structure has inspired a new aluminium composite material being tested for building safety applications.
Deloitte's Netherlands office, The Edge, is the poster child for smart buildings. Among many innovations, the offices are powered by super-efficient LED panels that require such negligible amounts of electricity that they run on the same cables that carry internet data. The panels are also imbued with sensors for motion, light, temperature and humidity -- a digital ceiling that wires the building like a brain's synapses.
Melbourne city council's headquarters Council House 2 (CH2), which is cooled using salt, is a worthy Australian example. The ceiling panels are chilled by water supplied by large tanks, each containing 10,000 stainless steel balls filled with a salt suspension that freezes at 16C. The frozen salt balls chill the water before circulating it to the panels when cooling is needed. The water returns to the tank 3C warmer, and the balls' absorption of heat moves the salt back into liquid phase, so they act collectively as a thermal storage battery.
CH2's architect, Mick Pearce, also designed the Eastgate mixed-used building in Harare. Its design, inspired by the way ants cool their mounds, allows passive cooling through its solar stack. Eastgate has side channels and a vertical tunnel along its centre through which hot air is drawn upward and out via a convection current.
Desha says European investors for the project baulked at the idea of a building without airconditioners so, though superfluous, they were bolted on after construction to assuage investors' fears. "That's very telling about human psychology and how a finance system doesn't trust the engineering. That has to change," she says.
Putting nature to work in an urban setting is more obviously showcased by an increasing number of buildings that are literally green. Vegetation covering the sides and roofs of office blocks not only breaks up a cityscape of concrete and glass, but performs the air cleaning and cooling functions of a forest. Sydney's One Central Park and Milan's Bosco Verticale are spectacular examples.
Pasona Group, a recruitment company in Tokyo, takes nature's bounty one step further, with integrated urban farming facilities. Hydroponic and soil-based farming of 200 species of vegetables and rice are grown and harvested for the staff cafeteria amid daily office functions, while tomato vines are suspended above conference tables and lemon trees act as screening partitions between desks.
The urban built environment is a relatively new phenomenon in the history of human habitation, while nature's most successful processes have been honed over millions of years. Using them as a blueprint seems a wise model for developing our existing cities and planning those of the future.