Definition of Nanotechnology:
Nanotechnology is the understanding and control of matter at the realm of 1 to 100 nanometers. (For reference, a piece of paper is about 100,000 nanometers thick.) At the nanoscale, matter functions differently from both the individual atomic and macroscopic scales, so some unique properties are available for use in the field.
Development of Nanotechnology:
Nanotechnology is a natural end-result of scientific development and our ability to understand and manipulate matter at smaller and smaller levels. Just as computers have gone from bulky, room-filling monstrosities to handheld computers, such reductions in size will continue until we reach fundamental physical limits.
Feynman & Nanotechnology:
On December 29, 1959, the influential American physicist Richard P. Feynman presented a talk to the American Physical Society entitled "There's Plenty of Room at the Bottom: An Invitation to Enter a New Field of Physics." Among physicists, this is respectfully called "the classic talk" (it's the first hit on a Google search of "classic talk"). He asked "Why cannot we write the entire 24 volumes of the Encyclopedia Brittanica on the head of a pin?" and introduced the concept of nanotechnology.
Spread of Nanotechnology:
Though Feynman's speech inspired many researchers, it wasn't until the mid-1980s that nanotechnology began to seep into the cultural mainstream conversation. In 1986, the MIT researcher K. Eric Drexler wrote Engines of Creation which laid out extensive prospects of emerging nanotechnology research.
Nanotechnology & Medicine:
One major application of nanotechnology is in the field of medicine, and in fact the knowledge gained from research of natural nanomachines, such as bacteria, has proven essential to the field. In this respect, it has developed some close connections with biophysics. It is theorized that man-made nanomachines could repair damage to the human body that is currently untreatable.
One material which is frequently discussed in nanotechnological research is graphene, an atom-thick form of graphite which was discovered by a University of Manchester team in 2004.
Preparing for a Career in Nanotechnology:
There are few degrees of study specifically in nanotechnology, so look for a good, well-rounded physics program. Nanotechnology works at tiny levels of matter, so knowledge of atomic, molecular, chemical and quantum physics is essential to this field of study. Working knowledge of biochemistry, chemistry, and biophysics, as well as a proficiency with complex mathematics, would also help qualify you for this field.