Adventures in Biomimetics
The imitation of nature in engineering has become one of the hottest trends in science. Almost every week, amazing technologies are being advanced the easy way – by observing how living things do it. We all stand to benefit from the design-based science of biomimetics. Here are a few recent examples.
1. Layered materials by imitation: PhysOrg titled an article, “Mimicking biological complexity, in a tiny particle.” MIT engineers are finding ways to make micromolds for multilayer structures the way the body does, to build tissue replacements for surgery. Some of the structures they’re working on may even contain biological collagen.
2. Spider silk: Spider webs remain one of the holy grails for biomimicy engineers. An article on Science Daily is titled, “Why Spiders Don't Drop Off of Their Threads: Source of Spider Silk’s Extreme Strength Unveiled.” It begins, “Spider thread has five times the tensile strength of steel and is stronger than even the best currently available synthetic fibers. Scientists have now succeeded in unveiling a further secret of silk proteins and the mechanism that imparts spider silk with its strength.” A professor at the Institute for Advanced Study at the University of Munich continues the praise: “The strength of spider dragline silk exceeds that of any material produced in laboratories, by far.” We should take a moment to consider what the spider has to do:
Spider threads consist of long chains of thousands of repeating sequences of protein molecules. These silk proteins are stored in the silk gland in a highly concentrated form until they are needed. The long chains with their repeating sequences of protein molecules are initially unordered and must not get too close to each other as they would immediately clump up. Only in the spinning passage, just before being used, are the threads oriented parallel to each other and form so-called micro crystallites that are, in turn, assembled to stable threads with cross links.
Superlatives for spider silk’s “extraordinary characteristics” continue throughout the article, alongside laments about how difficult they are to duplicate. Even the scary black widow was honored for its silk. Slow progress in creating synthetic silk is being made for children wishing to someday become a real Spider-Man.
3. Spider wear: Cops can take heart that progress is being made by a Dutch team, according to Live Science, to create better bullet-proof vests inspired by spider webbing. So far they have made a “spider skin” that can stop, well, low-velocity bullets… with improvements sure to come. “Such skin is still a long way from adding practical protection to humans, but it gives a glimpse of what future soldiers or would-be superheroes might expect.”
4. Bee internet: Want faster navigation through the internet maze? Think like a bee. Live Science reported,
Bees never seem to disappoint. Organized, selfless, altruistic and industrious, they are the primary pollinators of the world’s flowers, the makers of beeswax, propolis and honey. They’re expert communicators and fantastic fliers. They do many things so well that we don’t understand how they do them.
Now, one more skill can be added to the list of inexplicable bee attributes. Biologists from Queen Mary’s School of Biological and Chemical Sciences at the University of London have found that, through an unknown method, bees calculate the most efficient route possible between all the flowers in their environment, minimizing the energy required to gather nectar. With very simple brains, they solve complex routing problems that would confound most humans.
How can the study of bees help us? The article said, “we can learn how to optimize designs for information networks whose routes can’t be planned ahead of time.” One of the engineers explained how we could apply what they are learning: “we can imagine that ‘bee-inspired’ algorithms could ultimately be used to improve designs of fast-growing information networks (e.g. mobile phone networks, Internet) or transport networks (buses, trains) on which our modern societies rely.”
5. Dance with the bees: Meet RoboBee, a robot that has learned the waggle dance of the honeybee hive. New Scientist teased, “It smells, it buzzes, it even dances like a honeybee. In a field in Germany, RoboBee is making its first attempts at speaking to the insects in their own language.” Tim Landgraf of the Free University of Berlin in Germany made their invention out of foam. “Like a real bee, it can spin, buzz its wings, carry scents and droplets of sugar water, and give off heat,” reporter Michael Marshall said.
Did it fool the bees? Not quite; they did leave the hive, but went to their old feeders. Not having Rosetta Stone software for bee-ese, Landgraf is double-checking the video footage he took to see where he got the vocabulary wrong. He’s finding that “bee communication is even more sophisticated than von Frisch thought,” referring to the pioneer of waggle dance studies. He may have to put legs on his robot, because “some studies suggest there is a tap-dance element to the dance.”
6. Wave like cilia: Live Science began an article, “Thin, hair-like biological structures called cilia are tiny but mighty. Each one, made up of more than 600 different proteins, works together with hundreds of others in a tightly-packed layer to move like a crowd at a ball game doing ‘the wave.’” Federally-funded researchers at Brandeis University are trying to recreate this effect with actual biological proteins. Why? “… the new models could have applications in fields ranging from cell biology to physics and nanoscience” and “could even shed light on other self-organizing systems, such as bacterial colonies, flocks of migrating birds and traffic patterns.” Watch the short video clip to see cilia doing The Wave.
7. Gecko footprints: Scientists have learned a lot about how geckos scamper up walls with 500,000 tiny hairs on their toes that grip surfaces using atomic forces. Now, researchers at the University of Akron have made another discovery: geckos leave footprints. According to PhysOrg, trails of phospholipids have been found in gecko tracks, suggesting a kind of glue involved in the adhesive walk. “This material … has not been considered in current models of gecko adhesion and now provides the missing link in understanding superhydrophobicity, self-cleaning and fluid-like adhesion and release of gecko feet.” When we get the whole process figured out, what can we look forward to? How about “synthetic adhesives that could be reused thousands of times over, such as for wall-climbing robots, microelectronics, adhesive tapes and bioadhesives.”
8. Genetic code expansion: Biomimetics can also mean tweaking an existing biological structure or function. A Yale team, according to PhysOrg, has used the genetic DNA code to engineer a new protein that does not exist in nature. “Instead of creating something new in nature, the researchers essentially induced phosphorylation, a fundamental process that occurs in all forms of life and can dramatically change a protein's function,” the article explained. This is an epigenetic operation: “The rules for protein phosphorylation are not directly coded in the DNA but instead occur after the protein is made.” What might come of this tinkering with “biological switches”? The Yale team said it “will give us a completely new way to study disease states and hopefully guide the discovery of new drugs.”
9. Coral sunscreen: Instead of slathering oil on your skin, why not take a pill, inspired by coral? The BBC News said, “Scientists hope to harness coral’s natural defence against the sun’s harmful ultraviolet rays to make a sunscreen pill for humans.” At Kings College London they want to “uncover the genetic and biochemical processes behind coral’s innate gift.” Apparently the compounds produced in coral get passed on to fish that dine on them, providing hope that these compounds could be administered orally or in lotions for humans. They said, “there is a need for better sunscreens,” so why not save a step and use what corals manufacture so effectively?
10. Beetle feet for wounds: “Sticking plasters revolutionized the protection of minor wounds, but they’re not ideal for fragile skin,” began an article in Nature.1 “A material that mimics the adhesive properties of certain beetles’ feet might provide a solution.” Aristotle had investigated the beetle walk in ancient times, but it wasn’t till Y2K (2000) that the mechanism was described. Today’s acrylic adhesives lose their grip after repeated use, Karp and Langer said; “To bypass the need for these glues, researchers have focused on adhesion mechanisms used by animals such as beetles and geckos, whose feet stick to walls without any glue.”
Geckos and certain beetles use similar mechanisms, but with a difference: “Gecko spatulae are roughly hundreds of nanometres in length, whereas the mushroom-shaped structures of Chrysomelidae beetles’ feet are on the micrometre scale,” the authors noted. Now, Kwak et al. in work described by the authors, have succeeded in producing an adhesive without glue that mimics the mushroom-shaped projections on beetle feet. “Remarkably, the substrate maintained good adhesion through up to 30 cycles of attachment and removal, without causing significant damage to skin.” This could someday be a great boon to burn victims, skin graft patients and other people facing surgery.
In a book review for Science,2 Andrew Biewener considered “Animals as Mature Technology.” The new book from Harvard he reviewed was Engineering Animals: How Life Works, by Denny and McFadzean. He called the book “a readable romp through a diverse range of topics that include animal energetics, metabolism, and ecology; structural and circulatory mechanics; locomotion; sensory signal processing and control; and communication.” Animal parts featured include bat and dolphin sonar, bird flight, pterosaur bones, fish migration, and much more. It looks like biomimetics engineers will not run out of inspiring subjects any time soon.
1. Jeffrey M. Karp and Robert Langer, “Materials science: Dry solution to a sticky problem,” Nature 477 (01 September 2011), pp. 42–43, doi:10.1038/477042a.
2. Andrew A. Biewener, “Biomechanics: Animals as ‘Mature Technology’,” Science, 19 August 2011: Vol. 333 no. 6045 p. 938, DOI: 10.1126/science.1208791.
It’s nice to have good news to share between depressing reports about Darwinian bigotry and foolishness. Biomimetics is good for humanity. Everyone can join in the adventure, evolutionists and creationists, because there is no requirement for Darwinian just-so stories to interfere with the celebrations about design. We think even Darwinians would like to have biologically-inspired adhesives in their next surgery, coral-inspired sunscreen pills, real SpiderMan toys for their kids, and a bee-inspired faster internet. Keep science’s focus on good design in nature and let the evolutionary nonsense drop off the radar like old Victorian fads.