Книга: The Human Age

Weighing in the Nanoscale

Weighing in the 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.

In the 1966 science-fiction movie Fantastic Voyage, a tiny human-crewed submarine could sail through a patient’s turbulent bloodstream, careening down the rapids of an artery, dodging red blood cells, drifting through flesh lagoons, until they found the diseased or torn parts needing repair. With the advent of nanotechnology, this adventure leaves the realm of fiction. Researchers are perfecting microscopic devices known as nanobots and beebots (equipped with tiny stingers) that can swim through the bloodstream and directly target the site of a tumor or disease, providing radical new treatments.

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.”

There are nanobots invisible to the immune system, which shed their camouflage when they reach their work site. Tiny and agile enough to navigate a labyrinth of fragile blood vessels, some are thinner than a human hair. Researchers at the ?cole Polytechnique de Montr?al in Canada are developing a kind of self-propelled bacterium with naturally magnetic innards. In nature, the bacterium’s corkscrewlike tail propels it, and its magnetic particles point like a compass needle to guide it toward deeper water and away from the death knell of oxygen. Researchers are learning to steer the bacterium with precise tugs and pushes from an MRI machine, and at only 2 microns in diameter, the bacteria are small enough to fit through the smallest blood vessels in the human body. These harnessed bacteria can carry polymer beads roughly 150 nanometers in size; the goal is to modify the beads to carry medicines to tumors and other targets. Because we find it hard to imagine both ends of the visual spectrum—the cosmic infinite or the minutely finite—it sounds impossible. Yet we believe in them as surely as we do the unseen katydids in the woods.

We may imagine harnesses as large, leathery, and worn, and bacteria as invisibly tiny, able to slip into, through, and around objects or people. Harnessing bacteria doesn’t form a feasible image in the mind’s eye. You need to imagine bacterial horses and magnetic harnesses carrying polymer-bead bells that jingle a cancer-fighting drug. Still, a “sleigh” of medicine could become a new commonplace that slips into conversation the way a “flight” of stairs has, so comfortably that we no longer picture birds in flight when we see a staircase. We’re constantly minting new metaphors for the brain to use as mental shortcuts.

“Is there a sleigh for my illness?” someone may one day ask a doctor, as we now ask, “Is there a pill I can take?”[17]

Because boys love monster machines that dig, drag, roar, or explode, maybe the metaphor will be a “tug,” “tractor,” “missile,” or “submarine.” It might even be a “Phelps,” after the Olympic swimmer.

Another recent marvel of nanotechnology promises to alter daily life, too, but this one, despite its silver lining, is wickedly dangerous. Inevitably, it will inspire a welter of patents and ignite bioethical debates. Nano-engineers have devised a true silver bullet, a way to coat both hard surfaces (such as hospital bedrails, doorknobs, and furniture) and also soft surfaces (sheets, gowns, and curtains) with microscopic nanoparticles of silver, an element known to kill microbes. You’d think the new nanocoating would be a godsend to patients stricken with hospital-acquired sepsis and pneumonia and to the doctors fighting what has become a nightmare of antibiotic-resistant microorganisms that kill forty-eight thousand people a year.

It is. That’s the problem.

It’s possibly too effective. Remember, most microorganisms are harmless, many are beneficial, but some are absolutely essential for the environment and human life. Bacteria were the first life forms on the planet, and we owe them everything. Swarms of bacteria blanket us, other swarms colonize our insides, and still more flock like birds to any crease, cave, or canyon of the body they can find. Our biochemistry is interwoven with theirs. We also draft bacteria for many industrial and culinary purposes, from decontaminating sewage to creating tangily delicious foods like kefir, sauerkraut, and yogurt. So we need to be careful about the bacteria we target.

Will it be too tempting for nanotechnology companies, capitalizing on our fears and fetishes, to engineer superbly effective nanosilver microbe-killers, deodorants, and sanitizers of all sorts for home and industry? We may accept the changes nanotechnology creates in everyday life (such as antimalaria garments that ward off bugs) as part of the brave new world we deserve, yet we’re inventing them before thinking through their potential consequences. There’s no evidence that the antibacterial soaps available at the supermarket work better than soap and water, and in fact they may be hazardous. Triclosan—one of the standard ingredients in these soaps—is considered a pesticide by the FDA.

That’s why Kathleen Eggleson, a scientist at the University of Notre Dame, founded the Nano Impacts Intellectual Community, a monthly meeting that draws campus researchers, community leaders, and visiting scholars and authors to discuss the ethics and impact of new developments in nanotechnology. Her April 2012 paper published by the Center for Nano Science and Technology highlights the risk of unregulated products destroying microbial biodiversity. “Just this past December,” she points out, a coating for textiles “was the first nano-scale material approved as a pesticide by the FDA.” What if our nanopesticides accidentally kill the nitrogen-fixing bacteria that make our atmosphere breathable?

How incredible that we now have national committees and college seminars that debate bioethics, neuroethics, and nanoethics. We’re creating ethical predicaments that would have made Montaigne or Whitman blink. “I sing the body electric,” Walt Whitman wrote in 1855, inspired by the novelty of useful (not just parlor-trick) electricity, which he would live to see power streetlights and telephones, trolleys and dynamos. Whitman was the first American poet the technological universe didn’t scare. He often celebrated the steam engine, the railroad, and other new inventions of his era. In Leaves of Grass, his ecstatic epic poem of American life, he depicts himself as a live wire, a relay station for all the voices of Earth, natural or invented, human or mineral. “I have instant conductors all over me,” he wrote. “They seize every object and lead it harmlessly through me.… My flesh and blood playing out lightning, to strike what is hardly different from me.”

The invention of electricity equipped Whitman and other poets with a scintillation of metaphors. Like inspiration, it was a lightning flash. Like prophetic insight, it illuminated the darkness. Like sex, it tingled the flesh. Like life, it energized raw matter. Deeply as he believed the vow “I sing the body electric,” Whitman didn’t know that our cells really do generate electricity, that the heart’s pacemaker relies on such signals, and that billions of axons in the brain create their own electrical charge (equivalent to about a 60-watt bulb). A force of nature himself, he admired the range and raw power of electricity.

Yet I’m quite sure nanotechnology’s recent breakthroughs would have stunned him, such as the dream textile named GraphExeter, a light, supple, diaphanous material made for conducting electricity, which will revolutionize electronics by making it fashionable to wear your computer or cell phone.[18] Recharging would be automatic as nanosized generators convert the body’s normal stretches and twists into electricity through the piezoelectrical effect (what keeps a self-winding quartz watch ticking).[19] Wake Forest engineers recently invented Power Felt, a nanotube fabric that generates electricity from the difference in temperature between room heat and body heat. You could start your laptop by plugging it into your jeans, recharge your cell phone by tucking it into a pocket. Then, not only would your cells sizzle with electricity, even your couture clothing could chime in.

Would a fully electric suit upset flight electronics, pacemakers, airport security monitors, or the brain’s cellular dispatches? If you wore an electric coat in a lightning storm, would the hairs on the back of your neck stand up? Would you be more prey to a lightning strike? How long will it be before late-night hosts riff about electric undies? Will people tethered to recharging poles haunt airport waiting rooms? Will it become hip to wear flashing neon ads, quotes, and designs—maybe a lover’s name in a luminous tattoo?

Yet electricity has already lost its pizzazz. It’s hard to spot things hidden in plain sight. Even harder when they’re invisible. We take electricity for granted, unaware of it if lights and devices are turned off. Still, its specter haunts the walls all around us, sizzles in great looping strings that encircle us. If you have sockets in your house, you keep pocket lightning pulsingly at hand. Flip one switch and daylight floods the room; flip another and night falls like an iron door. The ancient Romans used to build their spas around natural hot springs; today we keep miniature electric hot springs in our homes to boil water for washing and bathing. Electric clocks watch over us while we sleep, an electric furnace (even gas or oil heat uses an electric pilot light) keeps us warm, and an electric fan or air conditioner cools us. In the summer we live in an electric igloo.

How Anthropocene that we “condition” the very air we breathe, flavoring its essence. For most of human history, we simply breathed the air that surrounded us, whatever nature delivered, whether it was fume-laced from oil deposits or salty-fishy from the coast. Before the Industrial Revolution, neighbors inhaled similar air. Now we tailor the breath that streams into and out of us. Neighbors may prefer their homes warmer, cooler, candle-scented, more humid, redolent of ammonia or bleach, cleaned by UV lights or “ozone-spiced” bulbs. We personalize our air!

We don’t find any of this strange, don’t regard it as unnatural. We don’t even notice it unless the electricity goes out, and then it’s as if the electric in our cells failed and we feel disconnected, a word we use when speaking of both power outages and psychic alienation (which feels like our inner grid has blown a million fuses). We too are electric, after all, a hive of minute, usually imperceptible jolts, as electrical signals leap like mountain goats from cell to cell throughout the body. Electricity, the brain’s telegraph, is almost instantaneous. Pinch a nerve in your back and dancing knives prick your skin. Pinch a nerve in your neck and a tiny electrocutioner throws a switch. But sexual tingles and jolts we find shockingly pleasurable, “electric flesh-arrows,” as Ana?s Nin calls them.

Electricity is a molecular tug-of-war. Life forms can’t exist without electric pumps in each cell. Ions of potassium and sodium, flowing into and out of a cell, produce a wave. The sodium is forced out, the potassium rushes in, the potassium is pushed out of another cell, the sodium rushes in, and so on. Ions fly like balls tossed by a one-armed juggler. It’s balance gone awry, regained, and lost again.

We reject things deemed too “wobbly,” “rickety,” or “unsteady.” We may condemn a person for being “unstable,” “unhinged,” or “unbalanced.” Yet deep in every cell, even the most slothful of us are falling out of balance and recovering. The body’s inner electric is not a steady stream. How ironic it is that we fight change in our lives and yearn for a state of permanence no life form can manage without dying—because we’re forever tumbling and snatching ourselves up before we smack the dirt and stay down.

Just as electricity ghosts throughout modern buildings everywhere and all the time, the same will soon be true of digital technology, woven into the walls, flowing through the floors, hidden all around and upon us. We’ll completely clothe ourselves in it, swim in it. As with the natural and man-made electric in our lives, we’ll probably ignore the clouds of technology we float on, under, and inside everywhere all the time. The brain relishes familiarity, loves being on autopilot, because then it can slur over the details and spend most of its sparking on something else. At the Oshkosh Airshow I attended one summer, the first wing-walker atop an old biplane drew gasps from thousands of people brought to a halt in amazement. The second fetched an anthology of admiring stares. By the third, a surprising number of people were blas? and continued milling about, chatting or shopping. You could almost hear their brains moaning, Oh, that again, another wing-walker. It doesn’t take much for a novelty to become invisible. And yet, isn’t this what we wish from exciting new technology, for it to slide invisibly into our lives, making them effortless and more enjoyable?

We’ll get used to living inside a digital bubble. Unless, perhaps, we must think hard when we connect via a brain-computer interface to the house’s fixtures. But even then, habit being what it is, we’d most likely come home, absentmindedly recall the code opening the front door’s lock, step over the threshold, daydream a hand swiping a light switch until the room brightens, mind’s-eye visualize the solar-electric shingles melting ice jams on the roof, while simultaneously worrying over a supposed affront at work or rebuff at school, anticipating dinner, fantasizing about a cute guy or gal, and hearing a stupid tune lodged in some spiky thicket of the brain.

Whether it’s hospital chairs robed in silver nanojackets to ward off bacteria, or invisibility cloaks, or degradable electronic devices that dissolve when you’re finished with them, or thin, flexible solar panels that can be printed or painted onto a surface, the writing is on the wall (though you’ll need a microscope to read it). And when it comes to the delicate balance of Earth’s life forms, it may be a small, small world after all.