Nanotechnology is a field of research and innovation concerned with building 'things' - generally, materials and devices - on the scale of atoms and molecules. A nanometre is one-billionth of a metre: ten times the diameter of a hydrogen atom. The diameter of a human hair is, on average, 80,000 nanometres. At such scales, the ordinary rules of physics and chemistry no longer apply. For instance, materials' characteristics, such as their colour, strength, conductivity and reactivity, can differ substantially between the nanoscale and the macro. Carbon 'nanotubes' are 100 times stronger than steel but six times lighter.

The commercial applications of nanotechnology are truly diverse.

Nanotechnology products are finding their way into a variety of different industries such as automobile, aerospace, biotechnology, cosmetics, defense, energy, electronics, health care, sports/fitness, textiles, footwear. The list below gives few examples how nanotechnology is set to be incorporated in the world around us .

Automobile: Tough and ultralight nanocomposite materials for sport cars and high-performance bikes, dirt-resistant paints and anti-fog windshields/mirrors with hydrophobic nanocoatings, better fuel cells for hybrid/electric vehicles.

• Aerospace: Carbon fiber composites for modern aircraft and helicopters that help decrease weight and enhance fuel efficiency. Also the carbon fiber composites help decrease the RADAR profile of combat aircrafts. Shape-shifting aerofoils and winglets in future aircrafts/space shuttles for extreme maneuverability and handling is also a topic of R&D in the aerospace industry.

• Construction: “Self-repairing” concrete made from application of nanocomposites and nanobiotechnology, easy to clean window glass for skyscrapers having coating of nanorods on the surface which can be cleaned only with water without soap/surfactants.

• Defense: Lighter and better nanocomposite helmets and bulletproofing for security/counterterrorism personnel, Self-monitoring, analysis and reporting technology (SMART) uniforms for tactical and special forces are a major research area in the defense sector. SMART weapons and even SMART ammunition may soon be seen in the inventory of the modern militaries of the world.

• Electronics: Nanoscale MOSFETs, carbon nanotube (CNT) FETs, graphene FETs, CNT field emitters, quantum cascade laser, single electron transistors (SET) to name a few.

• Health care: Nano-enabled drug delivery where particular agents are site selectively being delivered to treat complex diseases like cancer, tumors, and 4 A. Sengupta and C.K. Sarkar neurodegenerative diseases like Alzheimer’s. The “lab on a chip” or microfluidic and analyzing systems to automatically test a large number of pathogens, a more commonplace use is the antibacterial coatings of light activated Nano Titanium in toilets, hospitals, and interiors of public transport systems.