Nanotechnology is the field of greatest promise for new engineering applications across the board for the next several decades. It comprises any technological developments on the nanometer scale, usually 0.1 to 100 nm and it is also referred as microscopic technology. Nanotechnology influences almost every facet of every day life such as security and medicine. This involves the intentional manufacture of large scale objects whose discrete components are less than a few hundred nanometers wide. It exploits novel phenomena and properties at thenanoscale. It is interesting to note that nature employs nanotechnology to build DNA, proteins, enzymes etc. Nanotechnology uses Bottom up approach while traditional technology uses top down approach.
What does Nano mean?

“Nano” – derived from an ancient Greek word “Nanos” meaning DWARF.

“Nano” = One billionth of something

“A Nanometer” = One billionth of a meter

Equals 10 hydrogen atoms put shoulder to shoulder

There are 25 million nms in a single inch.

Richard Feynman in 1959 wrote an article entitled ‘There's Plenty of Room at the Bottom’, He points out on manipulating atoms and molecules directly. The idea is 1/10th scale machine to help to develop the next generation of 1/100th scale machine, and so forth. Further as things get smaller, gravity would become less important, surface tension molecule attraction would become more important.

Later Tokyo Science University professor Norio Taniguchi in 1974 described on the precision manufacture of materials with nanometre tolerances. Then K Eric Drexler in 1980s used the term nanotechnology and the term was reinvented. He wrote a book in 1986 titled Engines of Creation: The Coming Era of Nanotechnology. He expanded the term into Nanosystems: Molecular Machinery, Manufacturing, and Computation.
Important areas of research

Molecular Self-Assembly – organic, biological, and composites for molecular recognition, sensors, catalysis.

Sensors – chemical, biological, and radiological agents; - biosensors; gases (O2, H2).

Novel nanomaterial synthesis and characterization.

Lab-on-chip and Lab-on-a-CD.

Novel nanomaterials derived from biological molecules – protein nanotubes, viral scaffolds, bacteriophages.

Quantum mechanical modeling of nanomaterials.

Electronic structures and properties of nanoclusters.

Fluid dynamics in micro- and nano-channels.

Molecular electronics.

Toxicity of nanoparticles