the incredible world at nanoscale -- 9/15/14
Today's selection -- from The Human Age by Diane Ackerman. The incredible developments unfolding at nanoscale:
"We're not just seeing invisibles; we're engineering things on a minute, invisible-to-the-eye scale. 'Nano,' which means 'dwarf' in Greek, applies to things one-billionth of a meter long. In nature that's the size of sea spray and smoke. An ant is about 1 million nanoparticles long. A strand of hair is 80,000 to 100,000 nanometers wide, roomy enough to hold 100,000 perfectly machined carbon nanotubes (which are 50 to 100 times stronger than steel at one-sixth the weight). A human fingernail grows about 1 nanometer a second. About 500,000 nanometers would fit in the period at the end of this sentence, with room left over for a rave of microbes and a dictator's heart.
"I'm stirred by the cathedral-like architecture of the nanoscale, which I love to ogle in photographs taken through scanning electron microscopes. One year in college, I spent off-duty hours hooking long-stranded wool rugs after the patterns of the amino acid leucine (seen by polarized light), an infant's brain cells, a single neuron, and other objects revealed by such microdelving. How beautifully some amino acids shine when lit by polarized light: pastel crystals of pyramidal calm, tiny tents along life's midway. Arranged on a slide or flattened on a page, they glow gemlike but arid. We cannot see their vitality, how they collide and collude as they build behavior. But their nanoscale physiques are eye-openers, and more and more we're turning to nature for inspiration.
"We used to think that wall-climbing geckos must have suckers on the soles of their feet. But in 2002, biologists at Lewis & Clark College in Portland, Orgeon, and the University of California at Berkeley released their strange findings, and science was agog. Viewed at the nano level, a gecko's five-toed feet are covered in a series of ridges, the ridges are tufted with billions of tiny tubular elastic hairs, and the hairs bear even tinier spatula-shaped boots. The natural force between atoms and molecules is enough to stick the spatulas to the surface of most anything. And the toes are self-cleaning. As a gecko relaxes a toe and begins to step, the dirt slides off and the gecko steps out of it. No grooming required.
"When I learned of gecko feet from a biologist friend with an infectious sense of wonder, the idea of sticky instantly changed from a gluey sensation to a triumph of nature's engineering. The next time I spied a gecko climbing up a stucco wall, my brain saw the tidy toes rising, and the spatula-tipped hairs clinging, even though my raw eyes couldn't see beyond the harlequin slither. Inspired by gecko toes, scientists have invented chemical-free dry bio-adhesives and-bandages, and all sorts of biodegradable glues and geckolike coatings for home, office, military, and sports.
"The nanotechnology world is a wonderland of surfaces unimaginably small, full of weird properties, and invisible to the naked eye, where we're nonetheless reinventing industry and manufacturing in giddy new ways. Nano can be simply, affordably lifesaving during natural disasters. The 2012 spate of floods in Thailand inspired scientists to whisk silver nanoparticles into a solar-powered water filtration system that can be mounted on a small boat to purify water for drinking from the turbid river it floats on.
"In the Namibian desert, inspired by water-condensing bumps on the backs of local beetles, a new breed of water bottle harvests water from the air and refills itself. The bottles will hit the market in 2014, for use by both marathon runners and people in third-world countries where fresh water may be scarce. South African scientists have created water-purifying tea bags. Nano can be as humdrum as the titanium dioxide particles that thicken and whiten Betty Crocker frosting and Jell-O pudding. It can be creepy: pets genetically engineered with firefly or jellyfish protein so that they glow in the dark (fluorescent green cats, mice, fish, monkeys, and dogs have already been created). It can be omnipresent and practical: the army's newly invented self-cleaning clothes. It can be unexpected, as microchips embedded in Indian snake charmers' cobras so that they can be identified if they stray into the New Delhi crowds. Or it can dazzle and fill us with hope, as in medicine, where it promises nano-windfalls. ...
"The futurist Ray Kurzweil predicts that 'by the 2030s we'll be putting millions of nanobots inside our bodies to augment our immune system, to basically wipe out disease. One scientist cured Type I diabetes in rats with a blood-cell-size device already.' "
|The Human Age: The World Shaped By Us|
|W. W. Norton & Company|
|Copyright 2014 by Diane Ackerman|
|179 - 181|