By David Goldenberg and Eric Vance
People have been lifting ideas from Mother Nature for decades. Velcro was inspired by the hooked barbs of thistle, and the first highway reflectors were made to mimic cat eyes. But today, the science of copying nature, a field known as biomimetics, is a billion-dollar industry. Here are some of our favorite technologies that came in from the wild.
1. Sharkskin—The Latest Craze in Catheters
Hospitals are constantly worried about germs. No matter how often doctors and nurses wash their hands, they inadvertently spread bacteria and viruses from one patient to the next. In fact, as many as 100,000 Americans die each year from infections they pick up in hospitals. Sharks, however, have managed to stay squeaky clean for more than 100 million years. And now, thanks to them, infections may go the way of the dinosaur.
Unlike other large marine creatures, sharks don't collect slime, algae, or barnacles on their bodies. That phenomenon intrigued engineer Tony Brennan, who was trying to design a better barnacle-preventative coating for Navy ships when he learned about it in 2003. Investigating the skin further, he discovered that a shark's entire body is covered in miniature, bumpy scales, like a carpet of tiny teeth. Algae and barnacles can't grasp hold, and for that matter, neither can troublesome bacteria such as E. coli and Staphylococcus aureus.
Brennan's research inspired a company called Sharklet, which began exploring how to use the sharkskin concept to make a coating that repels germs. Today, the firm produces a sharkskin-inspired plastic wrap that's currently being tested on hospital surfaces that get touched the most (light switches, monitors, handles). So far, it seems to be successfully fending off germs. The company already has even bigger plans; Sharklet's next project is to create a plastic wrap that covers another common source of infections—the catheter.
2. Holy Bat Cane!
The cane works using echolocation, the same sensory system that bats use to map out their environments. It lets off 60,000 ultrasonic pulses per second and then listens for them to bounce back. When some return faster than others, that indicates a nearby object, which causes the cane's handle to vibrate. Using this technique, the cane not only "sees" objects on the ground, such as trash cans and fire hydrants, but also senses things above, such as low-hanging signs and tree branches. And because the cane's output and feedback are silent, people using it can still hear everything going on around them. Although the Ultracane hasn't experienced ultra-stellar sales, several companies in the United States and New Zealand are currently trying to figure out how to market similar gadgets using the same bat-inspired technology.
3. Trains Get a Nose Job for the Birds
When the first Japanese Shinkansen Bullet Train was built in 1964, it could zip along at 120 mph. But going that fast had an annoying side effect. Whenever the train exited a tunnel, there was a loud boom, and the passengers would complain of a vague feeling that the train was squeezing together.
That's when engineer and bird enthusiast Eiji Nakatsu stepped in. He discovered that the train was pushing air in front of it, forming a wall of wind. When this wall crashed against the air outside the tunnel, the collision created a loud sound and placed an immense amount of pressure on the train. In analyzing the problem, Nakatsu reasoned that the train needed to slice through the tunnel like an Olympic diver slicing through the water. For inspiration, he turned to a diver bird, the kingfisher. Living on branches high above lakes and rivers, kingfishers plunge into the water below to catch fish. Their bills, which are shaped like knives, cut through the air and barely make a ripple when they penetrate the water.
Nakatsu experimented with different shapes for the front of the train, but he discovered that the best, by far, was nearly identical to the kingfisher's bill. Nowadays, Japan's high-speed trains have long, beak-like noses that help them exit quietly out of tunnels. In fact, the refitted trains are 10 percent faster and 15 percent more fuel-efficient than their predecessors.
4. The Secret Power of Flippers
One scientist thinks he's found part of the solution to our energy crisis deep in the ocean. Frank Fish, a fluid dynamics expert and marine biologist at Pennsylvania's West Chester University, noticed something that seemed impossible about the flippers of humpback whales. Humpbacks have softball-size bumps on the forward edge of their limbs, which cut through the water and allow whales to glide through the ocean with great ease. But according to the rules of hydrodynamics, these bumps should put drag on the flippers, ruining the way they work.
Professor Fish decided to investigate. He put a 12-foot model of a flipper in a wind tunnel and witnessed it defy our understanding of physics.
The bumps, called tubercles, made the flipper even more aerodynamic. It turns out that they were positioned in such a way that they actually broke the air passing over the flipper into pieces, like the bristles of a brush running through hair. Fish's discovery, now called the "tubercle effect," not only applies to fins and flippers in the water, but also to wings and fan blades in the air.
Based on his research, Fish designed bumpy-edge blades for fans, which cut through air about 20 percent more efficiently than standard ones. He launched a company called Whalepower to manufacture them and will soon begin licensing its energy-efficient technology to improve fans in industrial plants and office buildings around the world. But Fish's big fish is wind energy. He believes that adding just a few bumps to the blades of wind turbines will revolutionize the industry, making wind more valuable than ever.
5. What Would Robotic Jesus Christ Lizard Do?
There's a reason the basilisk lizard is often referred to as the Jesus Christ lizard: It walks on water. More accurately, it runs. Many insects perform a similar trick, but they do it by being light enough not to break the surface tension of the water. The much larger basilisk lizard stays afloat by bicycling its feet at just the right angle so that its body rises out of the water and rushes forward.
In 2003, Carnegie Mellon robotics professor Metin Sitti was teaching an undergraduate robotics class that focused on studying the mechanics present in the natural world. When he used the lizard as an example of strange biomechanics, he was suddenly inspired to see if he could build a robot to perform the same trick.
It wasn't easy. Not only would the motors have to be extremely light, but the legs would have to touch down on the water perfectly each time, over and over again. After months of work, Sitti and his students were able to create the first robot that could walk on water.
Sitti's design needs some work, though. The mechanical miracle still rolls over and sinks occasionally. But once he irons out the kinks, there could be a bright future ahead for a machine that runs on land and sea. It could be used to monitor the quality of water in reservoirs or even help rescue people during floods.
6. Puff the Magic Sea Sponge
The "skeleton" of the puffball sponge is a series of calcium and silicon lattices. Actually, it's similar to the material we use to make solar panels, microchips, and batteries—except that when humans make them, we use tons of energy and all manner of toxic chemicals. Sponges do it better. They simply release special enzymes into the water that pull out the calcium and silicon and then arrange the chemicals into precise shapes.
Daniel Morse, a professor of biotechnology at the University of California, Santa Barbara, studied the sponge's enzyme technique and successfully copied it in 2006. He's already made a number of electrodes using clean, efficient sponge technology. And now, several companies are forming a multimillion-dollar alliance to commercialize similar products. In a few years, when solar panels are suddenly on every rooftop in America and microchips are sold for a pittance, don't forget to thank the little orange puffballs that started it all.
7. Wasps—They Know the Drill
Don't be scared of the two giant, whip-like needles on the end of a horntail wasp. They're not stingers; they're drill bits. Horntails use these needles (which can be longer than their entire bodies!) to drill into trees, where they deposit their young.
For years, biologists couldn't understand how the horntail drill worked. Unlike traditional drills, which require additional force (think of a construction worker bearing down on a jackhammer), the horntail can drill from any angle with little effort and little body weight. After years of studying the tiny insects, scientists finally figured out that the two needles inch their way into wood, pushing off and reinforcing each other like a zipper.
Astronomers at the University of Bath in England think the wasp's drill will come in handy in space. Scientists have long known that in order to find life on Mars, they might have to dig for it. But without much gravity, they weren't sure how they'd find the pressure to drill down on the planet's hard surface. Inspired by the insects, researchers have designed a saw with extra blades at the end that push against each other like the needles of the wasp. Theoretically, the device could even work on the surface of a meteor, where there's no gravity at all.
8. Consider the Lobster Eye
There's a reason X-ray machines are large and clunky. Unlike visible light, X-rays don't like to bend, so they're difficult to manipulate. The only way we can scan bags at airports and people at the doctor's office is by bombarding the subjects with a torrent of radiation all at once—which requires a huge device.
But lobsters, living in murky water 300 feet below the surface of the ocean, have "X-ray vision" far better than any of our machines. Unlike the human eye, which views refracted images that have to be interpreted by the brain, lobsters see direct reflections that can be focused to a single point, where they are gathered together to form an image. Scientists have figured out how to copy this trick to make new X-ray machines.
The Lobster Eye X-ray Imaging Device (LEXID) is a handheld "flashlight" that can see through 3-inch-thick steel walls.
The device shoots a small stream of low-power X-rays through an object, and a few come bouncing back off whatever is on the other side. Just as in the lobster eye, the returning signals are funneled through tiny tubes to create an image. The Department of Homeland Security has already invested $1 million in LEXID designs, which it hopes will be useful in finding contraband.
9. Playing Dead, Saving Lives
When the going gets tough, the tough play dead. That's the motto of two of nature's most durable creatures—the resurrection plant and the water bear. Together, their amazing biochemical tricks may show scientists how to save millions of lives in the developing world.
Resurrection plants refer to a group of desert mosses that shrivel up during dry spells and appear dead for years, or even decades. But once it rains, the plants become lush and green again, as if nothing happened. The water bear has a similar trick for playing dead. The microscopic animal can essentially shut down and, during that time, endure some of the most brutal environments known to man. It can survive temperatures near absolute zero and above 300°F, go a decade without water, withstand 1,000 times more radiation than any other animal on Earth, and even stay alive in the vacuum of space. Under normal circumstances, the water bear looks like a sleeping bag with chubby legs, but when it encounters extreme conditions, the bag shrivels up. If conditions go back to normal, the little fellow only needs a little water to become itself again.
The secret to the survival of both organisms is intense hibernation. They replace all of the water in their bodies with a sugar that hardens into glass. The result is a state of suspended animation. And while the process won't work to preserve people (replacing the water in our blood with sugar would kill us), it does work to preserve vaccines.
The World Health Organization estimates that 2 million children die each year from vaccine-preventable diseases such as diphtheria, tetanus, and whooping cough. Because vaccines hold living materials that die quickly in tropical heat, transporting them safely to those in need can be difficult. That's why a British company has taken a page from water bears and resurrection plants. They've created a sugar preservative that hardens the living material inside vaccines into microscopic glass beads, allowing the vaccines to last for more than a week in sweltering climates.
10. Picking Up the Bill
Marc Meyers, a professor of engineering at the University of California at San Diego, has started to understand how the bill can be so light. At first glance, it appears to be foam surrounded by a hard shell, kind of like a bike helmet. But Meyers discovered that the foam is actually a complicated network of tiny scaffolds and thin membranes. The scaffolds themselves are made of heavy bone, but they are spaced apart in such a way that the entire bill is only one-tenth the density of water. Meyers thinks that by copying the toucan bill, we can create car panels that are stronger, lighter, and safer. Toucan Sam was right; today we're all following his nose.
This story originally appeared in a 2009 issue of mental_floss magazine.