The term “nano” refers to the metric prefix 10-9. It means one billionth of something. “Nano” can be ascribed to any unit of measure. For example, you may report a very small mass in nanograms or the amount of liquid in one cell in terms of nanoliters.
So, what is nanoscience? Nanoscience is the study of structures and materials on the scale of nanometers. To give you an idea of how long a nanometer is, this printed page is about 75,000 nanometers thick. When structures are made small enough—in the nanometer size range—they can take on interesting and useful properties.
Nanoscale structures have existed in nature long before scientists began studying them in laboratories. A single strand of DNA, the building block of all living things, is about three nanometers wide. The scales on a morpho butterfly’s wings contain nanostructures that change the way light waves interact with each other, giving the wings brilliant metallic blue and green hues. Peacock feathers and soap bubbles also get their iridescent coloration from light interacting with structures just tens of nanometers thick. Scientists have even created nanostructures in the laboratory that mimic some of nature’s amazing nanostructures.
Because nanostructures are so small, specialized methods are needed to manufacture objects in this size range. Scientists use beams of electrons or ions to etch features as small as 25 nanometers into metal, silicon and carbon-based materials. In addition to being formed on these solid material surfaces, nanostructures can also be formed in liquids. Nanostructures can be created by reacting chemicals in liquids and gases to generate nanofibers, nanocrystals and quantum dots, some as small as one nanometer wide. Scientists are even learning how to build three-dimensional structures at the nanoscale. Called nano-electro-mechanical systems, or NEMS, these devices might one day be used like microscopic robots to carry out tasks too small for humans to do themselves. For example, NEMS could carry out surgery on a single cell or act as mechanical actuators to move around individual molecules.
In order to observe and study nanostructures, specialized equipment must be used. If you wanted to magnify something ten times, you could use a magnifying glass that fits in your pocket. If you wanted to magnify something 200 times, you would need a microscope that may weigh several pounds and take up part of a desk. To magnify nanoscale structures, high-powered microscopes that fill an entire room are needed!
Nanoscience has already impacted our lives with innovations such as stain-resistant fabrics inspired by nanoscale features found on lotus plants and computer hard drives, which store information on magnetic strips that are just 20 nanometers thick. Scientists and engineers from several disciplines including physics, chemistry, biology and materials science use nanoscience principles for advanced applications in energy, medicine, information storage, computing and elsewhere. Although breakthroughs in any research field are difficult to predict, the future of nanoscience will likely involve scaling up from atomic assembly and individual nanodevices to macroscopic systems and structures with evolving properties and multiple functions.