Introduction to Nanotechnology
Weighing in on Scale
Nanotechnology is the science of the extremely tiny. According to the US Government’s National Nanotechnology Initiative (NNI) “nanotechnology is the understanding and control of matter at dimensions of roughly 1 to 100 nanometers, where unique phenomena enable novel applications.” Nanotechnology is unbelievably miniscule. It is so small that even the most powerful conventional microscopes cannot see it. To put things in perspective, if the world were scaled down so that people averaged 100 nanometers tall, the Moon would be about 8 inches (20.5 cm) across—about the size of a basketball or a soccer ball. The Earth would be roughly 30 inches (76 cm) in diameter, or just small enough to squeak through a doorway.•
The nanoscale is the scale of atoms and molecules, the fundamental building blocks of the material world. At the nanoscale, scientists can start affecting the properties of materials directly, making them harder or lighter or more durable. In some cases, simply making things smaller changes their properties—a chemical might take on a new color, or start to conduct electricity when re-fashioned at the nanoscale. Nanoscale particles tend to be more chemically reactive than their ordinary-sized counterparts because they have more surface area.
In other cases, nanotechnology is about not only shrinking, but fundamentally changing the internal structure of compounds. Pure carbon, for example, takes two familiar forms: diamond and graphite (pencil lead). But by arranging carbon into precise nanometer-scale structures, a new product can be made that is up to thirty times stronger than steel, yet is one sixth the weight. This form of carbon (called a “nanotube,” or, more accurately, “nanotubes”) is one of the earliest forms of nanotechnology.
This sort of nanotechnology is currently being used for a wide variety of applications, and more than six hundred nanotechnology-enabled consumer products are on the market. Carbon nanotubes are used to make bicycle frames and tennis rackets lighter and stronger. Nano-sized particles of titanium dioxide and zinc oxide are used in many sunscreens, to block UV radiation more effectively without making your skin look pasty white. New tupperware features nanoscale silver that are antimicrobial, to prevent food stored in them from going bad. Clothes are treated with nano-engineered coatings that make them stain-proof or static-free. And computer chips using nanoscale components are ubiquitous in consumer electronics, from computers to mp3 players, digital cameras to video game consoles—“Moore’s Law,” which states that processors double in computing power every two years, is now driven by the relentless miniaturization of computer components deep into the nanoscale.
Thus far, nanotechnology remains a science in its infancy. Its potential goes far beyond these products: it will affect virtually all of the devices and materials we deal with in everyday life, from consumer products to food to medicine. Novel nanostructures could serve as new kinds of drugs for treating common conditions such as cancer, Parkinson’s, and cardiovascular disease, or as artificial tissues for replacing diseased kidneys and livers. Dangerous side effects of current treatments (like chemotherapy) may be engineered away. Nano-engineered solar panels could produce many times more energy than current types, while being lighter and more durable. Nanotech batteries last longer and are lighter and more powerful than their current counterparts. Foods could be engineered to improve nutritional value, tasted, or shelf life.
Dollars and Sense
In 2007, $60 billion worth of nano-enabled products were sold, and this figure is predicted to rise to $150 billion by 2008. Nanotechnology will also produce employment opportunities, with an anticipated 7 million jobs generated globally by nanotechnology in the next decade. By 2014, the Lux Research group predicts that $2.6 trillion in manufactured goods will incorporate nanotechnology — about 15% of total global output.
As a new field, nanotechnology is just beginning to deliver on its promise. But, like many new technologies, safety and ethical concerns about its use remain. Little hard research has been done on the health risks of nanotechnology, and there are so many different sorts of nanotechnology that it is hard to characterize those risks. Even the most fundamental questions about risk remain hard to answer. It is not clear, for example, how to measure exposure to nanomaterials: whereas with conventional materials, weight or volume are typically used, with nanomaterials, surface area may be a better predictor of the risks of exposure.
Nanoparticles’ small size might allow them to get places that conventional particles would not be able to go. This could mean penetrating to deep within the lungs when inhaled, then passing into the bloodstrean and reaching other organs. Or it might lead to nanometer-scale particles spreading through the environment and building up in places you wouldn’t normally find pollutants.
The very small size of nanoparticles in some products has raised concerns that they might be released into the air and inhaled, or end up in food (intentionally or unintentionally), and lead to harm as a result. But research into what might and might not be a cause for concern is still at a very early stage.
It is also possible that these miniscule particles might also pass through systems designed to prevent environmental releases of larger particles and enter our air and water; environments where they may provoke unintended consequences. Some nanoparticles have demonstrated an ability to bind to sediments and contaminating substances in the soil and air. As a result, they could become a mechanism for the widespread transport of pollutants in groundwater and air. But more research is still needed to separate speculative risks from real ones.
At the end of the day, nanotechnology is about doing things differently. Even though current applications of nanotechnology might seem rather crude, they are advancing what we can achieve in significant ways. And future applications will become increasingly sophisticated, giving scientists and engineers the ability to tackle challenging problems that affect us all - including treating cancer, generating clean/renewable energy, and providing clean water anytime, anyplace. Inevitably, these new and emerging applications will raise important questions concerning how we develop safe and acceptable nanotechnologies. Perhaps the greatest challenge to benefiting from nanotechnology is having the foresight to develop and use it wisely.
• The average human height (in the US) is about 168 cm. The Moon is about 3,475 km in diameter; Earth is about 12,750 km across.