Butterfly Cities and Spider Optics
Skycrapers of the future may shine in brilliant butterfly colors. Optical biosensors may be made from spider webs. These are just a few of the engineering marvels coming from biomimetics—the imitation of nature.
Walls of butterfly light: A press release from University of Pennsylvania features Shu Yang’s work to imitate two desirable properties of butterfly wings: optical intensification with “structural color,” and hydrophobicity (exceptional water resistance). Both of these properties work for butterflies because of the structure of the wing scales.
By etching wafers with a laser, Yang’s team has succeeded in creating material with these properties. Joanna Carver on New Scientist asked why this research is important, and found out what’s coming for futuristic cities:
Why do this? As it turns out, we have plenty to gain from butterflies. Yang has a grant to develop butterfly-inspired hydrophobic coatings for drier, cleaner and hence more efficient solar panels. But it doesn’t stop there – Yang has a vision of butterfly cities. She’s working with architects to create a low-cost version of her artificial butterfly wing material. “Specifically, we’re interested in putting this kind of material on the outside of buildings,” Yang said. “The structural colour we can produce is bright and highly decorative.”
The colors can be controlled electronically, Yang says. Building coated by this material will also be more energy efficient, environmentally friendly, and self-cleaning. So instead of the drab concrete look of many old downtown buildings, futuristic cities may shimmer and shine with beautiful colorful light, inspired by butterflies. The story was picked up by Science Daily and PhysOrg.
Spider optics: Did you know spider silk conducts light almost as good as glass fibers? That “hidden talent” was featured in a press release from the Optical Society of America (OSA), which is working on harnessing silk’s optical properties for use in biosensors, lasers, and microchips. The copy on PhysOrg begins with a photo of a handsome golden orb web spider, decked out in yellow spotted coat and striped legs, balanced upside down on its web of ideal material engineers seek to replicate.
“Spiders use their silk to catch lunch. Now physicists are using it to catch light,” the OSA press release begins. One team is using actual spider silk to guide light in photonic chips, while another is trying to imitate the proteins to manufacture the silk. Like the butterfly wing, the spider’s material is eco-friendly, hardy and renewable. Spider silk was already highly prized for its flexibility and durability. For it to have this additional property is remarkable. One engineer remarked, in fact, “There are materials that can do one of each, or a few of each, but seldom all of each.”
That’s not all the OSA is looking at. How about “spider plastic”? Imitation plastics made of spider silk might some day be used for implantable devices that the patient’s body can resorb. Even a prototype biodegradable laser was created from the stuff. The “spider optics” experiments showed that silk can direct light as well as transmit it. Another benefit is that it comes out of the spider ready to use.
The press release states that Biomedical engineer Fiorenzo Omenetto of Tufts University in Boston gave a TED talk last year about his work with silkworm silk, hoping that “these recent successes will help more people become excited about the potential of this remarkable material.” Biomimetics is a 99% Darwin-free, sociologically friendly research program everyone can get behind. The remaining 1% consists of the usual Darwin spin some reporters put on it, but evolution really contributes nothing.
This is the way out for imprisoned science. It makes people excited, it stimulates research, and it helps humanity. What’s there to dislike? This could well be the thing needed to give science education a shot in the arm without any school board fights. Textbooks can silently ditch the Haeckel embryos for pictures of butterflies next to skyscrapers, and drop the peppered moths for orb-web spiders next to state-of-the-art optical devices. Think of the fun science labs and science fair projects! Students will eagerly learn the details of biology in the process. Nobody will miss the old icons of evolution in the gold rush over new knowledge, improved living and wealth and job creation by the new generation of biomimetics entrepreneurs. NSF and NIH, put our money here! Job creation from biomimetics projects via technology transfer will raise revenues. Everybody wins. Darwin was so 1859; this is 2012. Let’s all get with the 21st century program; it’s not zero-sum, it’s win-win!