A nanometer (nm) is a unit of length equivalent to one billionth (10-9) of a meter. For comparison, a single sheet of paper is approximately 100,000 nm thick and a strand of DNA is 2.5 nm across. By studying and controlling matter at this nanoscale (1-100 nm), scientists can alter individual atoms and molecules. These alterations can lead to changes in the physical, chemical, biological, and optical properties of matter. When compared to their larger counterparts, nanoparticles can exhibit more or less strength, flexibility, reactivity, reflectivity, or conductivity.
After only 20 years of research and development, the creation of nanotechnologies and nanodevices is occurring at a rapid rate. Nanotechnology is aiding and revolutionizing many different aspects of science and industry, including energy, environmental science, homeland security, transportation, food safety, information technology, and medicine. As with any new technology or field of study, it is important to examine the potential for unintended consequences, especially those related to human and environmental health.