Animals in technology

We got a little acquainted with chromatophores last month — the pigment cells in cephalopod skin that allow it to change colour so that the animal can camouflage itself. We've seen it in its most stunning effect with octopodes (watch the two videos below to have your mind blown, for real), but they can change both the colour and texture of their skin.

No one has yet been able to replicate the way a cephalopod can change the texture of its skin, but scientists at Harvard have been working for over a year on something called "soft robots" — squishy silicon things that can change their colour and shape — either to blend into an environment or to stand out. For example, in the case of a rescue application, the robot could glow in the dark. It still looks like it has a bit of development to go, though.

Japan's Shinkansen, or Bullet Train, has been around since 1964. They can travel over 300 kilometres an hour, which is awesome, right? Except, there was a problem: tunnel boom. This is where the train, on entering a tunnel, would create a massive amount of air pressure that would result in a large sonic boom as the train exited.

The solution? Kingfishers. The shape of the bird's head and, more specifically, its beak, means that it can enter the water for prey with almost no splash. When the same aerodynamic shape was applied to the front of the bullet train, it eliminated tunnel boom completely — and, as a side bonus, shaved around 10-15 per cent off the energy usage of the train.

If you've ever had an occasion to look at a gecko's toes (we recommend it, they're adorable as heck), you'll notice that they're covered with ridges running from side to side, which are called lamellae. These lamellae are made up of hundreds of tiny keratin fibres (the same stuff as claws) — the setae. These give the gecko extraordinary grip, enabling it to run along virtually any surface, even vertical glass.

A few years back, researchers at Manchester University, UK, used a similar principle to develop "gecko tape". Covered with synthetic setae, it had more grip than an adhesive tape. Since that time, others have worked on the substance, including the University of Kiel in Germany and the University of Massachusetts in the US, but a product has yet to hit the market.

If you take a look at the photograph above, you'll notice the leading edge of the whale's fin is rather bumpy. These bumps are called tubercles, and they actually make the whale faster in the water. They do this by breaking the line of pressure against the fin as the whale moves through the water, pushing it into smaller channels, and enabling the whale to move faster using less energy than if the fin had been straight — a form factor that humans had previously believed more efficient.

By applying this shape to turbine blades, Dr Frank E Fish was able to make them more energy efficient — a particularly useful property, particularly when it comes to harvesting wind power.

There's something curious about sharkskin. Although sharks are smooth and dynamic in shape, their tiny scales are ridged and jagged — a property that not only helps them move faster through the water, but goes a way towards prohibiting the growth of microbes, by reducing the available surface for microbes to adhere to and creating an unstable surface.

These properties have been replicated by Sharklet, a company that creates adhesive films for environments such as hospitals, where bacterial transfer needs to be reduced. The film uses the diamond-and-riblet pattern of shark scales — which Dr Anthony Brennan ash determined is textured so as to discourage micro-organisms from settling — to create a safer, more hygienic environment.

Marine life just keeps surprising us. The 2005 Mercedes-Benz Bionic concept car looks a little dorky, but it's surprisingly aerodynamic. It was modelled after the boxfish — a similarly dorky-looking fish whose shape, nevertheless, is an excellent example of rigid aerodynamics, with a shape that can move efficiently in the water with minimum energy, while enclosed in an armoured shell. Much like you'd want a car to be, actually. The result is a vehicle that reduced the drag coefficient found in similar compact cars by up to 65 per cent.

Arachnophobia warning: the next image contains a (very cute) spider. Use the navigation above to skip it if you need to.

We all know that spider silk is astonishingly strong, able to exhibit (in the case of draglines) a tensile strength similar to that of alloy steel. But it's the way a spider can move that interested researchers at the Fraunhofer Institute for Manufacturing Engineering and Automation IPA, Germany. Spiders have no muscles in their legs, instead moving them by using hydraulic pressure. Pretty interesting, huh? It's this that gives spiders the ability to move the way they do, crawling, running and even leaping great distances (for their size).

It was with this in mind that the researchers built a spider-bot that, its builders say, can enter zones that are off-limits to humans — for example, due to a chemical spill. Its legs move using hydraulics, allowing it to move with agility over uneven ground. And the coolest bit? It was made using a 3D printer, which means that it can be manufactured quickly and cheaply.

This one wasn't so much inspired by animals as it was made out of them. Computer scientists at Japan's Kobo University made a series of channels to serve as logic gates. When released into these channels, soldier crabs — which are well known for their swarming behaviour — could be manipulated into travelling where the scientists wished them to go by casting a shadow over the areas that were off-limits. In this way, they found that they could recreate a functional OR gate.

We have to admit, we don't entirely understand what's going on, but you can read the study for yourself here (PDF).

Green fluorescent protein (GFP) glows bright under ultraviolet light. It has been used by researchers in biochemistry and molecular biology to observe processes that had previously been difficult to see, such as nerve growth, gene expression, cell division and chromosome replication. Because of this, its developers were awarded the 2008 Nobel Prize in Chemistry.

Where did it come from? A small fluorescent jellyfish, called Aequorea victoria, in which the protein glows when it comes into contact with calcium. It was first extracted and purified by marine biologist and organic chemist Osamu Shimomura, who has been working on the protein since around 1960.

The Namib Desert Beetle lives in one of the driest parts of the world — the Namib Desert in Africa, where rainfall is just 1.4 centimetres a year. Yet somehow, the beetle manages to find enough water to drink. It's actually the beetle's shell wherein the magic resides: its texture of bumps and valleys channels water from morning fog. As the fog comes in contact with the shell, it moves away from the bumps and into the valleys, which then funnel the droplets down so that the beetle can drink the water.

The US's Defense Advanced Research Projects Agency (DARPA) and the US National Science Foundation funded the research that allowed MIT professors Robert Cohen and Michael Rubner to first study, then replicate the phenomenon. The two led a team that developed a material that combines a water-repelling surface with water-attracting bumps, to trap and channel water.

The South American Tungara Frog protects its eggs by creating a floating foam nest in which they can incubate, safe from sunlight, heat and dehydration. It can also last up to two weeks — a property that researchers of the University of Cincinnati, Ohio, thought particularly interesting.

They decided to replicate the design of the frogs' nest to synthesise photosynthesis, as it concentrates the reactants well, while keeping out air and light. Because nothing would be draining the energy produced by the photosynthesis — such as a plant, which uses solar energy to survive — the captured solar energy can be converted directly into sugars. These can then be converted into substances such as ethanol and other biofuels — but the technology has not yet been developed for large-scale applications.

(Tadpoles image by Geoff Gallice, CC BY 2.0)