Six ways nature has inspired tech innovations
Whale fins and cow udders, wasp appendages and gecko feet - just some of the natural phenomena that have inspired technological innovation over the years.
The field, known as biomimicry or biomimetics, has already given us well-known practical applications, such as cats' eyes for the road and Velcro for our fastenings.
But more recent examples include superstrong mini-robots and prototype surgical needles.
Evolution has had hundreds millions of years to perfect its designs, whereas engineering has only been around for a nano-second, relatively speaking.
But studying nature's mechanics is helping us produce ever better man-made materials and structures.
Nacre, also known as mother of pearl, is found in the inner layer of the shells of molluscs such as mussels.
Along with cat skin and cow udders, it has "auxetic" properties, make it good at absorbing impacts.
"Auxetic material is a material where when you pull it, it actually gets fatter rather than thinner," Prof Andy Alderson, principle research fellow at Sheffield Hallam University, explained to the BBC earlier this year.
He has a new PhD programme exploring the use of auxetic material in sports protection wear such as shin pads and cricket helmets - and it may have a medical application, too.
"It could lead to new materials for artificial inter-vertebral discs for the relief of chronic back pain," he said.
Man-made auxetics now include honeycombs and foams, fibres and fabrics, as well as carbon fibre-reinforced composite materials.
Geckos in space
US space agency Nasa has been learning a few tricks by observing the gecko.
Tiny hairs on their feet allow these small lizards to grip and climb walls - and they don't lose their stickiness over time. The harder they press their feet the stickier they become.
Aaron Parness and colleagues at the the Jet Propulsion Laboratory in Pasadena have developed a material containing minute synthetic hairs that stick to a surface when a force is applied to make the hairs bend.
Prototype objects have been developed which might in future be able to act as anchors on board the International Space Station - but the technology may also be able to be used on its exterior, by repair or inspection robots.
Using the same principle, researchers at Stanford University in the US have developed tiny robots that can drag more than 2,000 times their own weight.
A team led by Prof Sangbae Kim have built a robotic "cheetah" at the Massachusetts Institute of Technology (MIT).
This summer they revealed that their robotic cheetah can now run at up to 13mph (21km/h) and can also jump over obstacles by itself.
"The general goal of our lab is to understand the locomotion aspect of animals," said Prof Kim in an explaining video on the MIT website.
"We are focusing on four-legged animals, to understand how they efficiently run in the field in nature so we can take the inspiration and use it in the engineering world."
The team hopes this research may lead to a completely new form of transport, making the car obsolete.
Dr Ferdinando Rodriguez y Baena from Imperial College has spent the last six years developing Sting (Soft Tissue Intervention and Neurosurgical Guide), a prototype needle that could be used during delicate brain surgery.
Sting was rather appropriately inspired by the humble female wood wasp, which uses a bendable, needle-like ovipositor to bore into wood and then lay her eggs.
The computer-operated needle is made of tiny interlocked polymer shafts that move together, minimising damage to surrounding areas, and which make the needle good at travelling along curves.
Dr Rodriguez y Baena heard about the wasp's ovipositor during dinner with Oxford University zoologist Prof Julian Vincent, who has spent his entire career studying biomimetics.
"You would not know the design started off with a wood wasp - and that is a strength," says Prof Vincent.
"It shows you how unlikely some of the biomimetics stuff can be."
Whales and wind
The bumps on a humpback whale's fin aid its agility in the water - an effect discovered, appropriately enough, by Dr Frank Fish (yes, we know whales are mammals).
He called it the "tubercle effect" and founded a company called the Whalepower Corporation, to improve the efficiency of fans, turbines, compressors and pumps.
Shark skin is covered in tiny ridged scales known as dermal denticles that optimise water flow, reduce drag and enable the predatory fish to swim faster.
Inspired by this observation, Speedo developed it Fastskin swimwear range which aimed to replicate this effect and streamline swimmers' bodies. The firm claimed that the new suits "revolutionised the swimming world".
But scientists have failed to find any significant performance-related benefits that could be linked directly to the properties of the swimwear itself, and the aerospace industry has also struggled to replicate significant improvements.
"Aerospace people found the amount of fuel saved [during experiments with plastic grooves on wings] wasn't really worth it," says Prof Vincent.
"Plus it made the aircraft more difficult to wash."
Replicating nature's sophistication is still proving difficult in many cases, however.
"People have been trying to make spider silk for 3,000 years and we still haven't done it," says Prof Vincent.
"The nearest we've got so far is Kevlar which is used on the sails of boats."
Kevlar is an incredibly strong, but very light, polymer that is widely used - perhaps most famously in protective clothing. It was accidently discovered by chemist Stephanie Kwolek in the 1960s.
"It was the nasty gunge in the bottom of a test tube," says Prof Vincent. "Most people looked at it and threw it away."
But high temperatures are required to make Kevlar because of the high-energy bonds between its molecules that make it so tough.
When it comes to the clever spider, "we can do the chemistry but we can't do the spinning," says Prof Vincent.