The first thing you notice about the entomology collections department, Lepidoptera division, at the Smithsonian’s Museum of Natural History is a faint, elusively familiar odor. Mothballs. I briefly contemplated the cosmic irony of mothballs in a room full of moths (and butterflies, a lineage of moths evolved to fly during the day) before turning to Bob Robbins, a research entomologist. “There are many insects that will eat dried insects,” he said, “so traditionally you kept those pests out using naphthalene, or mothballs.”
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The mothballs have been phased out (in favor of freezing new specimens to kill any pests), but that lingering smell, as well as the endless drawers of insects pinned under glass and carefully arrayed in row after row of steel cabinets for taxonomic posterity, only heightens the sense of age in the hushed chamber. Time seems to stand as still as the millions of specimens.
But pore through those drawers, through the precisely spaced squadrons of swallowtails and sunset moths, and a different idea begins to form: This is not a dormant repository, but a laboratory that investigates an extraordinarily successful enterprise. Over some 150 million years, these “products” have been ruthlessly prototyped, market-tested, upgraded, refined and otherwise made new and improved as the world around them changed. Each of these fragile specimens is a package of innovation waiting to be understood and adapted.
This is the idea behind the increasingly influential discipline of biomimicry: that we human beings, who have been trying to make things for only the blink of an evolutionary eye, have a lot to learn from the long processes of natural selection, whether it’s how to make a wing more aerodynamic or a city more resilient or an electronic display more vibrant. More than a decade ago, an MIT grad named Mark Miles was dabbling in the field of micro-electromechanical and materials processing. As he paged through a science magazine, he was stopped by an article on how butterflies generate color in their wings. The brilliant iridescent blue of the various Morpho species, for example, comes not from pigment, but from “structural color.” Those wings harbor a nanoscale assemblage of shingled plates, whose shape and distance from one another are arranged in a precise pattern that disrupts reflective light wavelengths to produce the brilliant blue. To create that same blue out of pigment would require much more energy—energy better used for flying, feeding and reproducing.
Miles wondered if this capability could be exploited in some way. Where else might you want incredibly vivid color in a thin package? Of course: in an electronic device display. Qualcomm, which acquired the company Miles had formed to develop the technology, used it in its Mirasol display. “We exploit the phenomena of optical interference,” says Brian Gally, senior director of product management at Qualcomm. Lurking beneath the glass surface is a vast array of interferometric modulators, essentially microscopic (10 to 50 microns square) mirrors that move up and down, in microseconds, to create the proper color.
Like the butterfly’s wings, “the display is taking the white ambient light around us, white light or sunlight, and through interference is going to send us back a color image,” Gally says. Unlike conventional LCD screens, the Mirasol doesn’t have to generate its own light. “The display brightness just automatically scales with ambient light.” As a result, the Mirasol consumes a tenth of the power of an LCD reader. Qualcomm used the display in an e-reader and is offering it for license to other companies.
Though biomimicry has inspired human innovations for decades—one of the most often-cited examples is Velcro, which the Swiss engineer Georges de Mestral patented in 1955 after studying how burs stuck to his clothes—better technology and more nuanced research have enabled increasingly complex adaptions. Design software created by German researcher Claus Mattheck—and used in Opel and Mercedes cars—reflects the ways trees and bones distribute strength and loads. A fan created by Pax Scientific borrows from the patterns of swirling kelp, nautilus and whelks to move air more efficiently. A saltwater-irrigated greenhouse in the Qatari desert will use condensation and evaporation tricks gleaned from the nose of a camel. Now, thanks in part to continuing innovations in nanoscale fabrication, manufacturers are bringing an expanding array of products to market.
Biomimicry isn’t itself a product but a process, drawing on natural organisms and processes in order to spark innovation. Organizations and even cities can look to ecosystems for inspiration, says Tim McGee, a biologist and member of Biomimicry 3.8, a Montana-based consultancy. In Lavasa—described as “India’s first planned hill city” by its developers, who hope to eventually build homes for more than 300,000 people there—the guild consulted with landscape architects. Thus the planting strategy included deciduous trees, forming a canopy to catch, and then reflect, through evaporation, nearly a third of the monsoon rain that hits it. That effect acts “like an engine that drives the monsoon inland,” says McGee, which helps prevent drought there. The hydrodynamically efficient shape of banyan tree leaves influenced the design of a better water-dispatching roof shingle, while water divertment systems were inspired by the ways harvester ants direct water away from their nests. The first Lavasa “town” has been completed, with four more projected to follow by 2020.
Everyone’s talking about ways to reduce the human footprint, or to get to “net zero” impact. But nature, says McGee, usually goes one step further: “It’s almost never net zero—the output from that system is usually beneficial to everything around it.” What if we could build our cities the same way? “What if, in New York City, when it rained, the water that went into the East River was cleaner than when it fell?” And what if, when forests caught fire, the flames could be extinguished by means that didn’t depend on toxic substances? “Nature creates flame retardants that are nontoxic,” notes McGee. “Why can’t we?”
For years researchers have focused on the chemistry of flame retardants, without results. But perhaps natural processes could offer some path to innovation in the laboratory, McGee says. Maybe it’s the way jack-pine cones open in the face of heat (to allow reproduction even as fire destroys the forest), or the way eucalyptus trees shed scattered pieces of quick-burning bark to suck up oxygen and take fire away from the main trunk. Jaime Grunlan, a mechanical engineer at Texas A&M, has developed a fire-resistant fabric that uses chitosan, a renewable material taken from lobster and shrimp shells (and a chemical relative of the chitin in butterflies’ wings), to create a nanolayer polymer coating that, when exposed to heat, produces a carbon “shell” that protects the fabric.
Lepidoptera epitomizes a few of the problems that have been hammered out on nature’s workbench over many millennia. In the evolutionary call and response between prey and predator, many moths have developed the ability to detect the ultrasound clicks of bats, and some can even send confusing countersignals. Butterfly wings tend to be black closer to their bodies, to help capture heat. Those wings are covered with a contaminant-resistant coating—they self-clean. The ornamental “eyes” on those wings, meant to scare away predators, are often positioned near the edge to minimize wing damage if the butterfly is bitten.
And then there’s the color—what we think of when we think of butterflies. “People call them flying flowers,” says Robbins. While some use color for camouflage, the most vivid species go the other route, advertising their toxicity to would-be predators in a gaudy display. The writer David Quammen dubs them the “bimbos of the natural world,” an “evolutionary experiment in sheer decorative excess.” Overall, Quammen writes, butterflies “represent an ideal of sweetness and gentle grace that seems almost innocent of the whole merciless evolutionary free-for-all.” And there’s a wealth of inspiration waiting to take flight on those gossamer wings.
Researchers at Shanghai Jiao Tong University, inspired by birdwing butterflies—the black area of their wings enables almost total light absorption, to trap heat—are creating a structurally similar super-black amorphous carbon film to help create more efficient solar technology. A project called NOtES, which grew out of research at Simon Fraser University in British Columbia, uses nanoscale light-interfering structures to create an anti-counterfeiting stamp that is more difficult to crack than a hologram and can be “printed” not only on bank notes, but on a whole range of other objects. Radio-frequency identification (RFID) tags, which are used for everything from tracking inventory to sensing the performance of one’s tires, tend not to work well in extreme environments, particularly where there’s water or metal. And so a company named Omni-ID adapted the interference principle to create a more reliable RFID, using tiny metal scales in the tags to improve their transmission of radio signals.
Given that the Morpho deploys color to attract attention, it seems appropriate that the butterfly has also inspired human fashion. Donna Sgro, a fashion designer in Sydney, Australia, and self-described “occasional lepidopterist,” created three dresses from a fabric called Morphotex, a pigment-free, iridescent blue material that draws its color from optical interference. Sgro says that while Morphotex eliminates the need for dyes (and thus potentially bears a smaller environmental footprint), her interest ranged beyond the usual “problem-solution-type design approach” that biomimists tend to follow. Fashion, after all, is about more than the basic need for clothing. How can the way nature uses aesthetics inform the way we do? Sgro is now studying for a PhD in biomimicry and fashion at the Royal Institute of Fashion in Melbourne.
Robbins and I left the Natural History Museum’s collections center and went to the nearby Butterfly Pavilion, and it was like a lepidopterous lovefest. A woman angled her smartphone to photograph a Monarch feeding on a flower. A Japanese tourist exclaimed as a Gulf Fritillary landed on her shoulder bag. A child squealed as a Morpho peleides slowly wafted its iridescent blue wings. It’s not easy to imagine this scene occurring with any other insect; justly or not, we don’t visit grub or ant pavilions.
I asked about the peculiar appeal of these insects. “They don’t sting, they don’t bite,” he said. “The ones that people see are generally pretty. Some of them are harmful agriculturally, but they’re pretty friendly guys and they’re a hell of a lot prettier than most other insects.” If only, I thought, people could now know how useful all that beauty can be.