Wednesday, 10 June 2009

Biomimicry: why the world is full of intelligent design

Forget human ingenuity - the best source of ideas for cutting-edge technology might be in nature, according to experts in 'biomimicry'

 
Robot in disguise? A gecko can climb walls speedily
Robot in disguise: the gecko's climbing ability has been copied by the Pentagon's latest robots

We humans like to think we're pretty good at design and technology – but we often forget that Mother Nature had a head start of 3.6 million years. Now, the way that geckoes climb walls, or hummingbirds hover, is at the centre of a burgeoning industry: biomimicry, the science of "reverse-engineering" clever ideas from the natural world.

Such efforts are, in a way, nothing new. Joseph Paxton's designs for the Crystal Palace that housed the Great Exhibition of 1851 were based, in part, on his observations of the structure of giant water lilies. George de Mestral, a Swiss engineer, came up with the concept of Velcro after observing the way burdock seeds clung to his clothes and the fur of his dog.

Yet as we become more and more concerned about the environmental impact of our behaviour, biomimicry is becoming fashionable.

"Imitating natural systems is about trying to mimic the amazing effectiveness of ecosystems, where the waste from one system or animal is used as the nutrients for another," says Michael Pawlyn, the director of a sustainable architecture firm and one of the designers of the Eden Project in Cornwall. "Often, by applying ideas from ecosystems you can turn problems into solutions that are better both environmentally and commercially."

Suppose, for example, you want to avoid the expense of cleaning a building. Scientists noticed that lotus leaves grow in muddy environments, yet remain pristine: the plants are self-cleaning. On closer examination, the researchers found tiny ridges and bumps on the leaves that stop water from spreading across the surface; instead, droplets slide away, carrying particles of dirt with them. They used this to come up with a paint that retains tiny bumps in its surface when it dries, copying the self-cleaning mechanism of the lotus.

This week, Pawlyn is lecturing on biomimicry at Schumacher College in Devon, which runs courses on the environment and sustainability. However, for those that can't make the lectures, we've collected a few examples of biomimicry at its best.

Beetling around in the desert

The idea sounds too good to be true: vast greenhouses-cum-power-plants that sit in the desert, producing food, energy and fresh water. Yet that is the proposed design for the Sahara Forest Project, unveiled last year by Pawlyn and others.

The idea was inspired by the Namibian fog-basking beetle, which has evolved a way to gather fresh water in the parched Namib desert. In the day, its matt black shell radiates heat; during the night, it becomes slightly cooler than its surroundings, causing fog to condense on its shell. In the morning, the beetle simply tips itself up, and lets the water trickle into its mouth.

In the larger-scale version, sea water collected from the air or pumped in from the coast evaporates at the front of a greenhouse, creating a humid environment suitable for growing crops. The water then condenses – leaving the salt behind – on the matt black pipes at the back of the greenhouse. Alongside sits a concentrated solar power array, which uses mirrors – cleaned by this distilled water – to concentrate the sun's rays. That heat turns the water into steam, driving turbines and generating electricity. The system not only produces five times as much fresh water as the greenhouse needs, but has twice the energy output of other solar-powered plants.

Although the condensation process was inspired by beetles, the operation also mimics a natural process: the hydrological system by which water moves around the Earth, from the atmosphere to the land, to the sea. The idea has already been tested in Tenerife, Oman and the United Arab Emirates, and Pawlyn claims that it is suitable for use in Africa, India, much of the Middle East, Australia and even parts of Spain.

Whale-powered turbines

Dr Frank Fish, an expert on how animals move, based at the University of West Chesterfield in Pennsylvania, was looking at a sculpture of a humpback whale, when he realised that the artist had put bumps on the whale's flippers. That made no sense: everyone knew that the leading edge of a wing had to be smooth and streamlined.

The gallery owner, however, assured Dr Fish that the bumps were in the right place. Intrigued, the doctor made a thorough investigation. What he discovered was that the mysterious bumps were precisely the right shape, and located in precisely the right places, to make even an animal as cumbersome as a whale extremely agile, as the bumps produce vortices that generate more lift and reduce drag.

Dr Fish has set up a firm called WhalePower, which uses this concept – which he refers to as "tubercle technology" – to design wind turbines, pumps and fans. The bumpy blades, he says, are quieter and more reliable – and produce 20 per cent more electricity a year.

Turning cardboard into caviar

Devised by Graham Wiles of the Green Business Network, the ABLE Project, based in Wakefield, near Leeds, began by involving disadvantaged people in cardboard recycling. What it evolved into, however, is a system that mirrors a natural process: the "circle of life", in which each living thing, or its waste, provides the food for another.

First, the young people involved started shredding the discarded paper and selling it as bedding for horses. Wiles then had the idea of collecting the soiled bedding and composting it in a wormery. He established 
a fish farm to raise Siberian sturgeon and ornamental Koi carp, feeding them on the worms. This year, the sturgeon produced their first batch of caviar.

The chain doesn't end there. Wiles has now planted willow trees, fed on composted sludge from the local sewage works, which will be used to fuel a biomass boiler, to provide the optimal growing temperature for the fish. The waste from the fish tanks will then fertilise an orchard, tree nursery and vegetable plot. As Pawlyn explains, the ABLE Project "demonstrates the potential to turn a waste material into 
a high value product while yielding numerous social, economic and environmental benefits".

A car that 'sees' like a bee

When Nissan set itself the goal of halving the number of deaths or serious injuries involving its vehicles between 1995 and 2015, it seemed an ambitious task. But the company had a secret weapon: the bumble-bee.

The Japanese firm recently unveiled a new micro robotic car, the BR23C, which avoids collisions by using sensors based on the creatures' compound eyes. With a field of vision more than 300 degrees wide, bees' eyes allow them to fly uninterrupted inside their personal space, and to dodge any obstacles.

In order to recreate the function of a compound eye, engineers at Nissan came up with the idea of a Laser Range Finder. The LRF detects obstacles up to two metres away within a 180-degree radius in front of the car, calculates the distance and sends a signal to an on-board microprocessor which helps the driver to avoid a collision.

"The split-second it detects an obstacle, the robot will mimic the movements of a bee and instantly change direction by turning its wheels at right angles or greater to avoid a collision," explains Toshiyuki Andou, manager of Nissan's mobility laboratory and principal engineer on the project. The firm hopes to incorporate the system into manually driven cars in the near future.

Dining out at the wormery

One of Pawlyn's more ambitious plans – for which he is still trying to find funding – is the Community Ecology Centre, in which the building's external form and internal function mimic the interconnectedness of the natural world.

"We wanted to create a celebratory form of architecture," he says, "which is commercially viable, links energy production and water purification, and acts as a social hub."

At the heart of the centre is a greenhouse, with tropical fruit and vegetables grown near the ceiling, where it's hotter. The produce will be served in a restaurant; the waste food will feed a wormery; the worms will be fed to tilapia, a breed of fish; and the tilapia will be served to the diners. Any rubbish will be processed by an anaerobic digester, a kind of processor in which micro-organisms break down the waste in an oxygen-free environment, producing biogas to heat the greenhouse and provide electricity.

Meanwhile, a "living machine", designed to mimic the filtration process that occurs in natural wetlands, will turn the sewage into clean water.

One giant leap for robotkind

Their names may sound like a collection of children's toys, but the latest robots funded by the Pentagon's Defence Advanced Research Projects Agency, or Darpa, are anything but playthings. The six-legged devices developed by the RiSE project, which is presided over by Professor Mark Cutkosky of Stanford University, are biologically inspired, based on insects and reptiles. The aim is to develop machines capable of walking both along the ground and up walls and other surfaces. "Stickybot" looks and climbs exactly like a gecko, using friction to adhere to smooth surfaces; while "DynoClimber" scuttles up walls like a cockroach, at speeds of 66cm a second (or 1.5 times its body length every second).

Researchers at Bath University are also working on robots that copy insects, in this case by jumping. With their lack of muscles, insects have to rely on unleashing small amounts of energy, like flattening and releasing a spring. Using a similar system, the "Jollbot" can leap 50cm into the air.

The robot's creator, Rhodri Armour, hopes that an advanced version would be able to leap and bound over the Martian surface, in areas where Nasa's Mars Rover is too ungainly to tread.