How nanotechnology could solve a host of eco-problems.
Sat, Jul 01, 2006 at 12:00 AM
Photo: Ivan Ermanoski, Theodore E. Madey/Rutgers University
Mention the term "nanotech" and it’s likely to conjure up images of formless gray goo and miniature life-forms run amok. This young, emerging field is so potentially radical that it readily plays into sci-fi fantasies: Take Michael Crichton’s thriller Prey, about a killer nanotech swarm that escapes from a Silicon Valley start-up’s lab.
Certainly nanotechnology — the science of designing and manipulating materials at a scale of one to 100 nanometers (a nanometer is one billionth of a meter; a human hair, by comparison, is 80,000 nanometers thick) — has had its share of detractors. No doubt, that’s fueled in part because at the nanoscale, familiar materials often acquire strange new properties and behavior: Gold looks ruby-red; graphite found in pencils becomes as strong as steel. Though critics contend that we don’t yet understand how nano-based materials affect human health or the environment, they also concede that done right, nanotech could alleviate some of the world’s most pressing environmental problems. Research is showing nanotech’s potential for helping reduce waste, conserve energy and natural resources, replace harmful chemicals with benign ones and pave the way for affordable renewable energy.
Nanotech, for instance, could help tackle the global challenge of providing clean water to billions of people who don’t have access to it. Companies such as eMembrane in Providence, Rhode Island, and Agua Via in Silicon Valley are making inexpensive nanoscale water filters that can trap microscopic impurities. Agua Via is commercializing a nanomembrane for water purification that’s only one molecule thick; it mimics the human kidney’s complex filtration and separation process.
Battery performance and energy storage are also getting a boost from nanotech. Today’s battries lose much of their power-producing capability and corrode over time, but nanotechniques are helping companies create smaller, lighter, more efficient batteries, says Jennifer Fonstad, managing director at venture capital firm Draper Fisher Jurvetson in Menlo Park, California. Fonstad’s company has invested in Solicore, a Lakeland, Florida, startup that makes thin, flexible, environmentally safe lithium polymer batteries to power tiny devices like smart cards and RFID tags.
Perhaps most significant, nano-based materials and methods are leading to breakthroughs that may correct tough problems with renewable energy — especially solar power. Startups such as Konarka Technologies, HelioVolt and Nanosolar are using nanotech to create “thin film” solar cells that are lighter, more flexible, and lower in overall cost than conventional silicon-based solar panels. Thin film is efficient at converting sunlight into energy — up to 20 percent efficiency rates, versus about 15 percent for silicon — but it has been expensive to manufacture, a challenge that nanotech is addressing. In a process akin to that of a high-tech printing press, tiny, light-sensitive nanoparticles are dispersed in “ink” that can be printed onto various materials such as metal roofing in a fast and economical way. “That wasn’t possible previously,” says Martin Roscheisen, CEO of the Palo Alto, California–based Nanosolar. The company has installed its thin-film systems at three test sites and will make them more widely available early next year.
The Lowell, Massachusetts–based Konarka is focusing on integrating solar power–generating nanoparticles into plastic and fabric. It is currently developing solar tents and uniforms for the Department of Defense, and the company sees its technology being used to create other types of powergenerating furniture, clothing and accessories. Other companies are employing nanotech to capture the full spectrum of the sun’s rays, including invisible infrared rays.
In the longer term, nanotech could hold the key to the much-hyped hydrogen economy. The main challenges to achieving that vision — where cars run on efficient, hydrogen-powered fuel cells — are storing hydrogen (a volatile gas) and extracting it cleanly (because some extraction methods require burning fossil fuels). Scientists at Rutgers University have found a way to extract hydrogen from ammonia by using surfaces covered with nano-size pyramids of the element iridium, which break down the ammonia into hydrogen and nitrogen without the pollution created by non-sustainable production methods. “Ammonia is such a hydrogen-rich molecule, it is a good way to store hydrogen if it can be extracted easily,” says Theodore Madey, a professor of physics and chemistry at Rutgers, whose group conducted the research.
So far so good — so why all the fuss? While most scientists dismiss the sci-fi notion that self-replicating nanobots would proliferate unchecked (the so-called “gray goo” scenario), some real health and environmental questions exist. Recent studies have indicated that nanoparticles can be harmful when inhaled or absorbed through dermal contact. In one study, researchers at Southern Methodist University put nano-size “buckyballs” into a fish tank with largemouth bass; within 48 hours, the fishes’ brain cells showed signs of damage. That’s especially worrisome with nanotech making its way into consumer products, including cosmetics and food. Experts also worry about nanotech being abused by criminals and terrorists, or even by governments, which could use it to monitor their citizens. Various parties have called for more study, regulations, or even an outright moratorium on nanotech development.
Still, the research continues, and the ecobenefits of nano may not end with these technologies. On a more fundamental level, nanotech could transform the way we make everything from electronics to medicine. By working directly with molecules and atoms, scientists are able to create stronger, lighter, higherperformance materials that require less energy to make and generate less waste. Rodney Brooks, director of MIT’s Computer Science and Artificial Intelligence Laboratory, describes nanotech’s promise this way: “Instead of growing a tree, cutting it down and building a table out of it, we will ultimately be able to grow the table.”
It may be a while before we are growing our furniture in labs. But if we can put aside the scenarios of gray goo, we may begin to see the potential for green good.
Keeping nano safe
Though government agencies such as the EPA are studying the eco-effects of nanotech, currently no guidelines or regulations pertain specifically to this emerging field. In the meantime, the Washington, D.C.–based Environmental Defense (ED) and the chemical giant DuPont are working together to create a framework for “the responsible development, production, use, and disposal of nanoscale materials.” The goal, officials say, is to learn from past mistakes with “miracle” products that were rushed onto the market with little study, like asbestos and chlorofluorocarbons (CFCs). “There have been a lot of examples where we’ve had a really promising technology that was widely released before we understood the consequences—with disastrous results,” explains Scott Walsh, a project manager for ED. “We’re excited about nanotechnology, but its potential impact is so broad that we have to get out in front and make sure we do it right.” The work has so far been kept under wraps, but ED and DuPont plan to begin publicizing their efforts in May (after press time).
Story by Amy Cortese. This article originally appeared in Plenty in July 2006. The story was added to MNN.com in June 2009.