Inventors Covet Nature's Engineering
Scientists and entrepreneurs can’t get enough of the design solutions found in the living world.
Snake-bots: PhysOrg wrote about “Flexible snake armor: Biology could inspire systems in engineering with minimized abrasion.” Snakes slither on all kinds of surfaces; their skin, therefore, is optimized to handle friction. Scientists at Kiel University looked at electron micrographs of snake skin cross-sections and found a gradient of stiff to flexible cells from outside to inside. “A material that has a transition from a stiff outside to a flexible inside can distribute an impacting force over a larger area, therefore decreasing the force on one single point,” a researcher explained. “Materials like this are like a flexible amour.” How could imitating this structure help humans? “Possible application areas can be found in the medical engineering sector, in which friction could for instance be optimized for artificial implants,” the article said. “Furthermore, the propulsion and conveyer technique market could profit from the abrasion minimization findings, since lubrication would have to be implicated less often.” Research on the mechanical properties of snake skin is “extremely new,” the spokesperson said.
Worm-bots: The pulsing action used by earthworms and snails, called peristalsis, has inspired another soft robot named “Meshworm” by its inventors. “Now researchers at MIT, Harvard University and Seoul National University have engineered a soft autonomous robot that moves via peristalsis, crawling across surfaces by contracting segments of its body, much like an earthworm,” a report on Science Daily says. “The robot, made almost entirely of soft materials, is remarkably resilient: Even when stepped upon or bludgeoned with a hammer, the robot is able to inch away, unscathed.” Faced with challenges of building artificial muscles and soft actuators, the team “looked to the earthworm for design guidance.” The article explains how they did it. A softbot using peristalsis would be useful for getting into tight places. Have they thought about just training earthworms?
Gecko tape update: The climbing ability of geckos with dry feet has been well studied, but how do they perform when wet? The BBC News and Science Daily revealed the secret: they trap air bubbles between the tiny hairs on the toe pads that cling to surfaces. Tokay geckos live in tropical rainforests where wetness is a problem. In natural circumstances, the geckos do fairly well in wet weather, but in the lab, when the toes were soaked, they lost adhesion. Researchers at the University of Akron hope to use what they are learning to develop a “gecko tape” that works on both wet and dry surfaces. The BBC article also discussed research in Japan with beetles that can walk underwater. The beetles use capillary action of an oily secretion to do the trick. “Inspired by this, the team created an artificial structure from silicone to mimic the adhesion and were able to successfully stick a plastic toy bulldozer to the bottom of a fish tank.”
Bamboo construction: The wood of bamboo decays in UV light and has poor fire resistance; otherwise, it has desirable properties for construction, PhysOrgs aid in “Bamboo: The new super construction material.” Those properties are its fast growth and a strength like steel. If they can overcome the undesirable properties, researchers at the University of Bath believe bamboo holds promise. They are experimenting with composites that boost its UV and fire resistance. “Possible applications of the resulting novel composites developed through this research programme include incorporation in architectural structures, particularly in critical areas such as joints and load bearing elements of buildings.”
Octobot camouflage: “…inspired by the squid and octopus,” PhysOrg wrote, Harvard scientists have “devised a rubbery robot … which can crawl, camouflage itself and hide from infrared cameras.” With “dynamic coloration,” this robot could someday help surgeons and search-and-rescue teams. “One of the fascinating characteristics of these animals,” a researcher said, “is their ability to control their appearance, and that inspired us to take this idea further and explore dynamic coloration.” Just as the animals can hide from predators or signal friends, the new robots could camouflage themselves or signal their positions to other robots. The progress was reported in Science Magazine (Morin et al., “Camouflage and Display for Soft Machines,” Science 7 August 2012: Vol. 337 no. 6096 pp. 828-832, DOI: 10.1126/science.1222149). The paper begins, “Synthetic systems cannot easily mimic the color-changing abilities of animals such as cephalopods.” They hope their soft-bots can mimic some of the functions, if not the anatomy, of squid and octopus.
Flower power: How to get more energy from sunlight? Follow the sun, like sunflowers do. “A field of young sunflowers will slowly rotate from east to west during the course of a sunny day, each leaf seeking out as much sunlight as possible as the sun moves across the sky through an adaptation called heliotropism,” began an article on PhysOrg. It’s a clever bit of natural engineering that inspired imitation from a UW-Madison electrical and computer engineer, who has found a way to mimic the passive heliotropism seen in sunflowers for use in the next crop of solar power systems.” The article includes a video clip about Hongrui Jiang’s invention using passive heliotropism that improved solar panel light harvesting by 10%. “But eventually, Jiang hopes to see huge industrial solar farms where fields of photovoltaic solar panels shift effortlessly along with the sunflowers that inspired him,” because “This is exactly what nature does.”
Ultimate hard drive: Science Now called DNA the “ultimate hard drive” for information storage. How about some “wow” stats? “When it comes to storing information, hard drives don’t hold a candle to DNA,” John Bohannon wrote. “Our genetic code packs billions of gigabytes into a single gram. A mere milligram of the molecule could encode the complete text of every book in the Library of Congress and have plenty of room to spare.” He reported, “researchers stored an entire genetics textbook in less than a picogram of DNA—one trillionth of a gram—an advance that could revolutionize our ability to save data.” It’s not practical for personal computers yet, but just wait; an engineer at the Craig Venter Institute said, “the field is moving fast and the technology will soon be cheaper, faster, and smaller.” Synthetic DNA – no cells required – has been put on rewritable devices: “an inkjet printer embeds short fragments of chemically synthesized DNA onto the surface of a tiny glass chip.” The researchers boast, “DNA chips are now the storage medium with the highest known information density.” New Scientist’s coverage of this achievement added even more “wow” factoids about DNA:
DNA is one of the most dense and stable media for storing information known. In theory, DNA can encode two bits per nucleotide. That’s 455 exabytes – roughly the capacity of 100 billion DVDs – per gram of single-stranded DNA, making it five or six orders denser than currently available digital media, such as flash memory. Information stored in DNA can also be read thousands of years after it was first laid down.
Researcher George Church even wrote his latest book in DNA, illustrations and all, said Science Daily. Another good thing about DNA encoding is that the molecule is stable at room temperature.
Fixing what happens: This is not exactly a biomimetics story, but it deals with a biological reality which, if handled better, would hold great promise for world health. The Bill and Melinda Gates Foundation, according to PhysOrg, sponsored a “Reinvent the Toilet Challenge” since much of the world lacks access to good sanitation (see YouTube video about the challenge). Cranfield University, one of the competitors, has come up with a human-powered device that extracts the water from refuse and concentrates it into briquets that can be used for fuel or fertilizer – and it’s not just for poor countries, too. The sanitary reapplication of digestive waste could go a long way to conserving water and preventing disease. As side benefits, new sources of energy and even fresh water could result when nature calls.
The BBC News joked that Gates is flushing his money down the toilet, but quickly explained that the initiative could prevent many deaths: for example, 1.5 million children die each year from diarrheal disease. “The project challenged inventors to come up with a toilet that operated without running water, electricity or a septic system. It needed to operate at a cost of no more than five cents (3p) a day and would ideally capture energy or other resources.” In a short video clip in the article, Gates described problems with current toilet designs. “Traditional flush toilets waste tons of drinking water and are often impractical in many areas of the developing world.” They use, in fact, 10 times more water than people drink. At a recent Reinvent the Toilet Fair, “In total 28 designs were shown off at the fair and the winner was a team from the California Institute of Technology” (see picture at Bill and Melinda Gates Foundation website). “Led by Prof Michael Hoffman, the toilet they designed was solar-powered and generated hydrogen gas and electricity. They won a $100,000 prize.”
Isn’t it refreshing to see science done for human good and environmental stewardship? Evolution was almost a no-show in these stories, just appearing in bit parts with no speeches. The Bill Gates challenge story is also a lesson about how wealth creation through capitalism can benefit the poorest of the poor. Gates built his fortune without government or U.N. help, starting in a garage. His mega-company, Microsoft, created thousands of jobs and made computing easier for the entire civilized world. Now, through some of the wealth created (not stolen from the poor), he is encouraging engineers to save millions of lives and promote environmental stewardship with a simple challenge that is long overdue: doing better with doo. Leftist redistributionist Marxists, are you paying attention? What has Darwin crap done for the world lately?