Why now? If it seems that nanotechnology and nanotechnology applications have begun to blossom in the last ten years, this is largely due to the development of new instruments that allow researchers to observe and manipulate matter at the nanolevel. Technologies such as scanning tunneling microscopy, magnetic force microscopy, and electron microscopy allow scientists to observe events at the atomic level. At the same time, economic pressures in the electronics industry have forced the development of new lithographic techniques that continue the steady reduction in feature size and cost. Just as Galileo’s knowledge was limited by the technology of his day, until recently a lack of good instrumentation prevented scientists from gaining more knowledge of the nanoscale. A better instrumentation for observing, manipulating and measuring events at this scale are developed, further advances in our understanding and ability will occur. One leader in nanotechnology policy has identified four distinct generations in the development of nanotechnology products, to which we can add a possible fifth:10
The above is from
Nanotechnology: The Future is Coming Sooner Than You Think
Joint Economic Committee United States Congress