Scientists Pursue Natural Champions
Animals and plants have what scientists want. They continue to pursue the technology inherent in some of the common organisms around us, hoping to lead to inventions to improve human life. Certain champions keep showing up in reports over the years, but other new ones are joining the ranks.
Spider power: Several reports continued to praise the wonder of spider web silk. Scientists have known for years that it is stronger than steel and Kevlar, Live Science said the Darwin bark spider (Caerostris darwini), a new species found in Madagascar, spins silk twice as strong as any previously studied silk, and twice as elastic. This “toughest biomaterial ever seen” is 10 times stronger than Kevlar.
Not only that, the spider manages to spin its giant webs across rivers, streams and lakes up to 25 meters across. “Our initial reaction was simply 'Wow!'” said one researcher. Another commented that the discovery “opens up new technological applications for spider silk that capitalize on C. darwini silk’s truly impressive combination of light weight and high performance.”
National Geographic posted a photo gallery that shows giant webs that could have been the inspiration for Shelob’s lair in Lord of the Rings. The spider catches large mayflies, but scientists believe that bats or small birds could get entangled in the large, super-strong webs. Learning how this little spider, less than an inch long, can spin such massive structures will probably keep the National Geographic Society busy for awhile.
Bird power: An old joke has a businessman saying, “I just flew in from Chicago, and boy, are my arms tired.” Flying like a bird has been a dream ever since man watched the effortless flight of our feathered friends. Now, for the first time, human-powered flight has been achieved in a new “ornithopter” that slowly flaps its wings as the operator pedals a cycle inside a compartment.
The Snowbird, invented by Todd Reichert of the University of Toronto, “represents the completion of an age-old aeronautical dream.” Reichert piloted and powered the test flight of Snowbird and was one of its lead developers. “Throughout history, countless men and women have dreamt of flying like a bird under their own power, and hundreds, if not thousands have attempted to achieve it,” he said. This represents one of the last of the aviation firsts.”
To really enjoy this achievement, watch one of the videos available at the BBC News and Live Science #1 and #2. It’s a pretty clumsy contraption compared to a sparrow or pelican, but getting a man with a 0.3 horsepower human “engine” off the ground with flapping wings is quite a sight.
Plant champions: Leaves act, in a way, like perfect solar cells. Why not follow their example? “A team led by a North Carolina State University researcher has shown that water-gel-based solar devices – ‘artificial leaves’ – can act like solar cells to produce electricity, an article on PhysOrg began. “The findings prove the concept for making solar cells that more closely mimic nature. They also have the potential to be less expensive and more environmentally friendly than the current standard-bearer: silicon-based solar cells.”
Will our homes some day be independently powered by rooftops of leaf-like solar systems? Dr. Orlin Velev of the University wants to “learn how to mimic the materials by which nature harnesses solar energy.” One challenge is to mimic the self-regeneration capabilities of plants. The other is to mimic their efficiency. While hedging his bets at this point about the potential for human technology at this early stage of development, he said, “we believe that the concept of biologically inspired ‘soft’ devices for generating electricity may in the future provide an alternative for the present-day solid-state technologies.” His team has even shown the ability to incorporate chlorophyll, plant’s light-snatching molecule, into his arrays, along with synthetic light-sensitive molecules. Science Daily accompanied their write-up with a photo of leaves uplifted under the sun.
- Plant champions II: It’s not just their light-gathering power that has some scientists excited about leaves. Their unique shapes offer interesting possibilities for invention. Scientists at the Max Planck Institute in Germany succeeded in taking a plant stem with leaves and replacing all the cells with iron carbide, a magnetic material. Why? “Biology’s intricate forms provide a wide range of templates for a variety of applications,” the article explained. Specifically, “Nature’s fine structures are also suitable for technical applications – they exist in a myriad variety of forms, they usually display high mechanical stability and, due to their large surfaces, provide suitable templates for catalysts and electrodes.” The structure of the leaves was preserved down to the last detail. Zoe Schepp, who carried out the experiment, said, “What is important about this study is that it shows how we can exploit nature’s formal variety to produce wafer-thin metal carbide structures in one simple step.”
- Gecko champion: Our biomimetic friend the gecko is back with a new trick. Scientists at the University of Illinois at Urbana-Champaign have found away to use the sticky-foot mechanism to print electronics on a variety of surfaces, like clothes, plastic, and leather. See the story at Science Daily. Will electronic clothes be in our future?
- Cell champions: Most cells have “primary cilia” that act as tiny antennae, sensing their environment. Science Daily and PhysOrg talked about a “cilia revolution” in materials science where inventors are using that strategy to build materials that can respond to thermal, chemical and electrical stimulation. “University of Southern Mississippi scientists recently imitated Mother Nature by developing, for the first time, a new, skinny-molecule-based material that resembles cilia, the tiny, hair-like structures through which organisms derive smell, vision, hearing and fluid flow,” Science Daily said. The “Man-made, hair-like structures [are] poised to change industry paradigms,” PhysOrg headlined. The “artificial cilia” produced by USM scientists respond to acidity, temperature and radiation by bending over and fluorescing blue. The fact that the researchers can control this behavior opens up “unlimited possibilities for future use.” The article continued, “Scientists long imagined what could be done if they could engineer cilia for other organic and nonorganic uses. But creating them solely belonged to the life nurturing processes of nature, until now.” Of course, they are not quite as elegant and exquisitely controlled as living cilia, but “There is no limit to dreaming up applications for such a material,” the article ended. The press release originated from the National Science Foundation.
- Jellyfish power: Plants don’t monopolize the solar power market. Some jellyfish contain green fluorescent protein (GFP) that holds promise for better solar cells, too. “When exposed to ultraviolet light, the GFP absorbs photons and emits electrons, which travel around a circuit to produce electricity,” an article on New Scientist reported. A team at the Chalmers University of Technology in Gothenburg, Sweden, is excited about the possibility “to create a biological fuel cell that generates electricity without the need for an external source of light” by using the ingredients of biological light. Their “jellyfish biophotovoltaic device” might be able “to power nano-devices embedded in living organisms,” the lead author said. The design is simple, green, and efficient.
- Beetle meter: Nature last week (470: p. 370, 09/23/2010) included a short research highlight about scientists at Sogang University in Seoul, Korea, who imitated the way the Hercules beetle changes color in muggy weather. “Inspired by the natural design of the Hercules beetle,” the short article said, “researchers have created a film that changes colour according to the ambient humidity.” What’s it good for? “A sensor made from the material would not need electricity and could be used in small medical or agricultural devices.”
- Bee democracy: Can biomimetics inform politics? Thomas D. Seeley, a professor of neurobiology and behavior, thinks so. He has written a new book on “Honeybee Democracy,” reported PhysOrg. What do our honey-making friends have to teach us? Seeley has observed the bees’s decision-making behaviors and observed that they tend to achieve optimal decisions, even though no one individual has a complete view of the situation. “Indeed, humans can learn much about democratic decision-making by looking at bees, Seeley said. If the members of a group have common interests, like the bees in a swarm, then the keys to good collective decision-making are to ensure the group contains diverse members and an impartial leader, and conducts open debates.”
Most of these articles said nothing about evolution. The one exception was the spider silk story. The champion spider was named after Darwin because it “may become a model for evolutionary studies,” said PhysOrg. One of the authors of a paper in PLoS One said, “these spiders may have evolved a novel mechanism for the production or assembly of their ‘super silk.’” Evidence was lacking for either of these assertions.
The authors of the article in PLoS One could only speculate about the evolution of this spider.1 “The rivers across which adult C. darwini suspend their webs are used as flyways by large insects, birds and bats,” they said. “It is tempting to speculate that Caerostris evolved giant webs under selection to capture such extraordinarily large prey.” Using “evolved… to” as a goal-directed action, however, is inconsistent with Darwinian contingency, however, and adding “under selection” does little to mitigate the fallacy. They had to admit that there was no evidence for it, anyway: “However, as appealing as the hypothesis that Caerostris evolved such extraordinary silk under natural selection for the capture of giant prey might be, the meager preliminary data that exist on Caerostris prey only found abundant smaller aquatic insects in their webs. Regardless, the webs allow access to habitat and prey that other spiders cannot utilize.”
1. Agnarrson, Kuntner and Blackledge, “Bioprospecting Finds the Toughest Biological Material: Extraordinary Silk from a Giant Riverine Orb Spider,” Public Library of Science ONE, 5(9): e11234. doi:10.1371/journal.pone.0011234.
Did the spider hunters help their Darwinist case at all with their ending paragraph?
In summary, we hypothesize that the world’s longest orb-webs and toughest silk coevolved within the genus Caerostris as species began to occupy a novel habitat – the flyways above rivers. This spectacular adaptation puts C. darwini at a considerable advantage over other forest dwelling species of orb spiders, by allowing Caerostris to ensnare abundant insects or other prey flying over water. Perhaps most importantly, our study demonstrates how understanding the ecologies of spiders can play a critical role in biomimicry. The discovery of C. darwini’s incredibly tough dragline silk followed from our initial observations about its extraordinary orb webs and greatly expand our understanding of the potential performance of silk fibers.
The bluffing here is odious. Darwinism had nothing to offer this discovery or the practical uses that might come from it. It wasn’t evolutionary theory that played the “critical role” in understanding the extraordinary orb webs this spider makes. It was ecology. Ecology as a science has no necessary connection to Darwinism. The team found this spider and predicted its webs would be strong, based on the habitat, and they were. What’s Darwin got to do with it? They produced no evidence of a mutation or selection effect that would have produced this extraordinary material. Evolution was only a distraction, a tumor, a parasite, a name-dropping gimmick to give their dictator, King Charles, some credit for a story that had everything to do with intelligent design, not evolution.
OK, enough of Darwin. We love biomimetics here because the stories are usually so interesting, amazing, useful, promising, and de-Darwinated (that’s like decaffeinated or detoxified). We’ve been reporting biomimetics stories for years, but many of them seem to predict future inventions that have not yet made it to market. Here’s a project: List products people are using today that have a plant or animal inspiration. In a sense, all aircraft could qualify, because the Wright brothers studied birds for ideas. Synthetic sponges seem to imitate their natural counterparts. We know that Velcro got its start when a man was curious how cockleburs stuck so effectively to clothing. There are three examples to get you thinking. This website lists ten interesting “product designs that are inspired by nature,” but not all of them are in common use yet. Send in your examples of biomimetic items you use, so that we can assemble a list of useful products we all use that had natural design, not Darwin, as their inspiration.