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Saturday, 28 April 2018

Mimicking the original designer.

To Match the Genius of Centipedes, Bats, and Peacocks, Scientists Play a Game of Catch-Up
Evolution News & Views

Pure science seeks understanding of "the nature of nature" and its operations. Applied science takes the insights from pure research and makes it work for human interests. What if you had a single word that incorporates both? Here's a contender for such a word: Biomimetics. The application side is clear, because engineers and inventors try to imitate nature's designs. But the pure-research side becomes active in the process, because you have to understand something before you can imitate it. This is a win-win bonanza for 21st-century science, and intelligent design, if not by that name, is at the center of it.

Drug discovery. We see both sides of the coin in a paper in  Nature Communications,, "Biomimetically inspired asymmetric total synthesis of (+)-19-dehydroxyl arisandilactone A." It begins, "Complex natural products are a proven and rich source of disease-modulating drugs [applied science] and of efficient tools for the study of chemical biology [pure science] and drug discovery." Nature is way out in front, the next sentence suggests: "The architectures of complex natural products are generally considered to represent significant barriers to efficient chemical synthesis." [Emphasis added.] It takes Olympic-level effort to scale these barriers, but by studying how a medicinal plant builds a complex organic compound, Chinese scientists think they are learning how to synthesize other molecules of interest.

Spider-man wannabees. Researchers at the  American Institute of Physics sound like kids at a Spiderman movie. They say "Wow!" at the "impressive weight-lifting abilities" in the silk of a particular spider. The muscles of human weight-lifters are impressive enough at the molecular level, but "Variations of this dynamic geometry appear elsewhere in nature, exhibiting a variety of mechanisms and structures and inspiring development in artificial muscle technology," they say. "Spider silk, specifically Ornithoctonus huwena spider silk, now offers the newest such inspiration" for a team of Chinese and American scientists. Thinking ahead to artificial muscles, these researchers had to study the spider's silk at the micro-level, learning about the proteins involved and how they become activated by water.

These spider silk fibers, actuated by water droplets, showed impressive behavior in all the ways that matter to muscle performance (or to super heroes that may need them to swing from buildings).
Bat robotics. "Advanced robotic bat's flight characteristics simulates the real thing," announces a headline from Engineering at Illinois News. Everybody is aware that robotic drones are the hottest thing these days in everything from toys to weapons. The smart guys at University of Illinois, in cooperation with Jet Propulsion Laboratory, have built the latest iteration of their bat-mimicking "bat bots."

Bats have long captured the imaginations of scientists and engineers with their unrivaled agility and maneuvering characteristics, achieved by functionally versatile dynamic wing conformations as well as more than forty active and passive joints on the wings. However, their wing flexibility and complex wing kinematics pose significant technological challenges for robot modelling, design, and control.
Researchers at the University of Illinois at Urbana-Champaign and Caltech have developed a self-contained robotic bat -- dubbed Bat Bot (B2) -- with soft, articulated wings that can mimic the key flight mechanisms of biological bats.

A video (above) shows off the invention and boasts about its design. But the human engineers running a flight test at the end of the clip look like kids playing with paper airplanes compared to the 'biological bats' whose elegant motions are shown in this Nature Video."Whenever I see bats make sharp turns or perch upside down with elegant wing movements, I get mesmerized," the lead engineer remarks. Clunky as Bat Bot is at this stage, both Live Science  and New Scientist believe that exciting applications can come from this advancing technology.

Dragonfly drone. A lab in Massachusetts appears to be besting the Illinois team, by creating an even smaller drone that mimics dragonflies. On closer reading of the  Live Science story about the DragonflEye project, though, we learn that the team at Charles Stark Draper Laboratory is actually outfitting live dragonflies with electronic backpacks. This allows them to send commands to the insects' flight muscles, turning them into cyborgs that they can control. "DragonflEye sees these tiny flight masters as potentially controllable flyers that would be 'smaller, lighter and stealthier than anything else that's manmade,'" the article says, but we don't know if the Illinois team will call it cheating to use live insects.

Bee bots. If honeybee numbers keep dropping, how will our crops get pollinated? Some inventors think that tiny quadcopter drones might be recruited as "artificial pollinators" in the future. Watch a horse trot into this biomimetics tale:

As bees slip onto the endangered species lists, researchers in Japan are pollinating lilies with insect-sized drones. The undersides of these artificial pollinators are coated with horse hairs and an ionic gel just sticky enough to pick up pollen from one flower and deposit it onto another. The drones' designers are hopeful that their invention could someday help carry the burden that modern agricultural demand has put on colonies.
See the horse hairs up close in New Scientist's  coverage. Now a problem: how to scale this up to tackle crops like almond orchards that can stretch for miles, where each tree can have 50,000 flowers to pollinate. Elizabeth Franklin doesn't think robotic pollinators will ever compete with live honeybee (The Conversation). A U.K. researcher rubs it in (Live Science):

In a blog post, he wrote that there are roughly 3.2 trillion bees on the planet. Even if the robo-bees cost 1 cent per unit and lasted a year, which he said is a highly optimistic estimate, it would cost $32 billion a year to maintain the population and would litter the countryside with tiny robots.
"Real bees avoid all of these issues; they are self-replicating, self-powering and essentially carbon-neutral," Goulson wrote in the post. "We have wonderfully efficient pollinators already. Let's look after them, not plan for their demise."

Plant ceramics. Harvard  has a whole institute dedicated to biomimetics: the Wyss Center for Biologically Inspired Design. The wizards there are hot on the trail of leaves of grass, according to news from Wyss, and that's not just poetic license. Impressed by grass's ability to "support its own weight, resist strong wind loads, and recover after being compressed," they thought that if they could 3-D print something like that, it would enable a very useful material for many applications. In order to invent "ceramic foam" usable in a 3-D printer, they had to look at grass carefully. "The plant's hardiness comes from a combination of its hollow, tubular macrostructure and porous, or cellular, microstructure, they found. "These architectural features work together to give grass its robust mechanical properties." So by printing their foam into honeycomb-like shapes, they're getting close to printing hierarchical microstructures with desirable mechanical, thermal, and transport characteristics: "Inspired by natural cellular structures" in a common blade of grass.

Speaking of ceramics, another team is trying to imitate the "unique structural and functional capabilities" of nacre (mother-of-pearl), by "Using graphene networks to build bioinspired self-monitoring ceramics" (Nature Communications). Pages and pages of graphs, mathematics, and chemistry show it's not easy to imitate an oyster.

Peacock dye.The  American Chemical Society  is involved in the gold rush, too, excited to announce that "Peacock colors inspire [a] greener way to dye clothes." The iridescent colors of birds and butterflies come not from pigments, but from geometric structures at the nanoscopic level that intensify certain wavelengths of light. Everyone from fashion designers to parents to the EPA will be happy to learn about better dyes inspired by peacock feathers. "Testing showed the method could produce the full spectrum of colors, which remained bright even after washing," an ACS team said. "In addition, the team said that the technique did not produce contaminants that could pollute nearby water."

For those not afflicted by arachnophobia, Phys.org  tells about another team at the University of Akron working on a similar idea to 3-D print dyes inspired by (ready?) tarantula hairs.

Centipede robots. What kid hasn't been fascinated by the wave-like motion of dozens of feet in caterpillars, centipedes, and millipedes? Some who grew up to become scientists didn't forget that fascination. Japanese scientists publishing in PLOS ONE are among them, describing, "Decentralized control scheme for myriapod robot inspired by adaptive and resilient centipede locomotion." Read in this open-access paper about how they tackled one of the major challenges, developing "a control scheme that can coordinate their numerous legs in real time." Some of us have enough trouble controlling two legs, let alone dozens. The breakthrough came by "drawing inspiration from behavioral experiments on centipede locomotion under unusual conditions," they say.

There's something satisfying about watching the brightest scientific minds as they try to play catch-up with the genius of centipedes, bats, and peacocks. Biomimetics is not for lazy scientists. Nature's designs are too sophisticated for Darwinian storytellers. They stimulate inspiration, perspiration, and admiration, with potential applications to benefit us all -- and the key word is design.

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