March 27, 2010 | David F. Coppedge

Biomimetics: Science for Now

Do you want science that makes a difference in our lives?  Look at real plants and animals with real solutions to practical problems.  That’s where researchers are making amazing discoveries with practical spinoffs.

  1. Shellfish materials:  Strong, lightweight structures are coming, thanks to the imitation of oysters and shellfish.  PhysOrg reported that researchers at the University of Helsinki are coming closer to manufacturing nacre-inspired polymers that are unbreakable, fire resistant, and gas free.  Such materials are a dream in electronics; they can insulate and are strong and flexible.  Lightweight, too – and they self-assemble when you get the conditions right.
        The press release ended with a quizzical juxtaposition of ideas: “The new material is an example of biomimetics, which aims to mimic the most attractive materials in the nature, but in simpler terms.”  The idea is that nature’s solutions are much more complex than ours.  But then one of the scientists was quoted saying it all just evolved:

    “The materials scientists are fascinated by the delicacy of natural materials.  The properties have been developed due to the lengthy process of evolution and in some cases extraordinary properties relevant to technology can be identified.  In addition to nacreous shells, the materials scientists explore for example mimics for silk, jaws, and bones.”

  2. Leaf mimic:  “Blueprint for ‘Artificial Leaf’ Mimics Mother Nature” announced Science Daily.  A presentation by Chinese scientists to the American Chemical Society showed how “design of artificial photosynthetic systems based on biological paradigms” is leading toward “a working prototype to exploit sustainable energy resources.”  This is a long-sought goal: to imitate the energy-efficient harvesting of sunlight achieved by plants and algae.  The scientists actually took “a closer look at the leaf” for ideas.  “Not too surprisingly, the structure of green leaves provides them an extremely high light-harvesting efficiency.”  The next step was clear: “The scientists decided to mimic that natural design in the development of a blueprint for artificial leaf-like structures.”
        The word “design” was as ubiquitous in this article as the word evolution was scarce: e.g., “design of novel artificial solar energy transduction systems based on natural paradigms, particularly based on exploring and mimicking the structural design.  The last sentence was a virtual manifesto for biomimetics: “Nature still has much to teach us, and human ingenuity can modify the principles of natural systems for enhanced utility.”
  3. Bee nose:  We all know about the sniffers of dogs, but did you know honeybees are their equals?  PhysOrg reported about how the Defense Department is not just imitating bees, but training them for active duty.  Maybe you never heard that “In 2010, bee training in the fields of defense and security, medicine, food, and building industries is big business.”  Bees are smaller, cheaper and easier to transport than dogs.  Honeybees with diodes on their backs are now being used to sniff out TNT.  Let them find the landmines, the military says, so that human farmers don’t have to find them “the ugly way.”
  4. Green materials:  As an environmentally-conscious citizen, you would like to reduce the use of styrofoam cups going into landfills, wouldn’t you?  Well, thank a seashell for finding a better use for them, said Science Daily.  “Scientists have made synthetic ‘sea shells’ from a mixture of chalk and polystyrene cups – and produced a tough new material that could make our homes and offices more durable.”  PhysOrg quipped, “Strength is shore thing for sea shell scientists.”
        And where did they get the idea?  “A team of materials scientists and chemists have taken inspiration from sea shells found on the beach to create a composite material from dissimilar ‘ingredients’.”  That’s how sea shells do it: they intersperse mineral crystals with proteins in ways that provide crack resistance and structural strength.  Researchers at University of Manchester are boasting as if they did the hard part: “We have replicated nature’s addition of proteins using polystyrene, to create a strong shell-like structure with similar properties to those seen in nature.”  Shouldn’t the shell – or the shell-maker – get the design credit?
  5. Spider silk:  Spiders are the “masters of materials sciencePhysOrg reminded us, and “ scientists are finally catching up.”  Attempts to understand and imitate spider silk have been reported here many times.  “Silks are among the toughest materials known, stronger and less brittle, pound for pound, than steel,” the article recapped.  “Now scientists at MIT have unraveled some of their deepest secrets in research that could lead the way to the creation of synthetic materials that duplicate, or even exceed, the extraordinary properties of natural silk.”  That leads to an interesting philosophical question.  If humans create it, is it natural?
        What the MIT team found out is that the arrangement of the silk elements makes the difference.  The protein components known as beta sheets “are arranged in a structure that resembles a tall stack of pancakes, but with the crystal structures within each pancake alternating in their orientation,” Markus Buehler, an MIT civil engineering professor, explained (see picture in the Science Daily article).  “This particular geometry of tiny silk nanocrystals allows hydrogen bonds to work cooperatively, reinforcing adjacent chains against external forces, which leads to the outstanding extensibility and strength of spider silk.”  Slight deviations in the length of the beta sheets leads to breakdown of the silk’s remarkable strength and flexibility, the team found.  Expect good things from what biomimetics is discovering:

    Buehler says the work has implications far beyond just understanding silk.  He notes that the findings could be applied to a broader class of biological materials, such as wood or plant fibers, and bio-inspired materials, such as novel fibers, yarns and fabrics or tissue replacement materials, to produce a variety of useful materials out of simple, commonplace elements.  For example, he and his team are looking at the possibility of synthesizing materials that have a similar structure to silk, but using molecules that have inherently greater strength, such as carbon nanotubes.
        The long-term impact of this research, Buehler says, will be the development of a new material design paradigm that enables the creation of highly functional materials out of abundant, inexpensive materials.

    The fact that the arrangement of elements is critical to their success is reminiscent of how the properties of DNA and proteins are critically dependent on the sequence of the building blocks.  Applying this new paradigm – that it is arrangement as much or more than material – provides a whole new design pathway for inventors, thanks to the lowly garden spider.

  6. Signal in the noise:  An article in PhysOrg sounds at first like a strictly physical engineering problem of how to amplify signal in a noisy environment using a principle called stochastic resonance.  But at the end of the article, the researchers talk about designing an “artificial neuron” that mimics the signal-enhancing capabilities of nerve cells.  Artificial neurons are defined as “simple computing, logic gates.  Their actions resemble the firing of signals as they are observed between neurons,” the article explains.  The team at University of Wurzburg “believes that its devices can be thus used in the future to mimic neuron action in artificial networks and to serve as sensors for signals usually hidden under the noise.”
        With neural networks in mind, their plans will imitate neurons even more.  In the brain, “actions cascade based in part on the noise of individual spiking neurons,” the article explained.  “This incredible sensitivity makes the devices an ideal candidate for quantum computing.”   Quantum computing has been a design goal for years.  Finding ways to maximize signal in a noisy environment, as neurons do, would allow circuits to keep getting smaller and more efficient despite increases in thermal noise that accompanies shrinking size.
  7. Snail armor:  Snails seem good for little more than amusing children, annoying gardeners and making the French say Bon appetit.  But they’re good for something else, reported Live Science: inspiring a new generation of body armor.  The article is an interview with Christine Ortiz, a materials scientist at MIT, who is studying a snail that lives near hydrothermal vents 2.5 miles deep in the Indian Ocean.  Athletes or soldiers might benefit from what she is learning: “Understanding the physical and mechanical properties of the snail could improve load-bearing and protective materials in everything from aircraft hulls to sports equipment.”  Other beneficiaries of snail-inspired materials could be emergency responders, firefighters, police officers, aircraft designers, commercial designers, and recipients of prosthetics coming out of regenerative medicine.  The interview pointed to a NSF press release from January about “the fantastic armor of a wonder snail.”

Dr. Ortiz was asked how she got into her field: “I was always fascinated, since I was a small child, by nature, biology, evolution, and related fields.”  Was one of those fields intelligent design?  Probably not, but she feels one of the most important qualities of a scientist is “The ability to see the unexpected in data, to fearlessly explore areas outside of one’s comfort zone, and to draw on and link to bodies of work in other fields, regardless of vocabulary and language barriers.”  Follow that advice consistently and you never know where your world view might end up.

Our entries on the imitation of nature are valuable in multiple ways (see 03/06/2010 and the other 200+ entries on biomimetics over the years).  For one, it is simply fascinating how animals and plants do what they do.  That’s why the Biomimetics and Amazing tags often go together.  In addition, these reports provide our readers a wide-ranging education in biology, physics, engineering, and even philosophy of science.  Think, too, of the teachable moments they provide for parents wanting to inspire their precocious youngsters with the wonders of nature and the possibilities of science as a career.  For another, unlike some scientific subjects of doubtful utility, biomimetics promises really cool technologies that are likely to make a big difference in human comfort, safety, security and convenience – all with lower energy costs and less impact on the environment.  (We still want the gecko boots, the lotus windshields and the spider-man gloves).  And for a final reason, the sheer entertainment value of watching evolutionists sit on the sidelines pretending to be relevant to these efforts that are design-based from start to finish is priceless.

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