One of the most exciting advances in science during the last couple of decades has been the development of nanotechnology. It is now finding myriad applications in medicine, food, water purification, cosmetics, electronics and many other fields. The US has the largest share (28 per cent) in the nanotechnology market, followed by Japan (24 per cent), and Europe (25 per cent, main players Germany, France and UK). Nanomaterials owe their special properties due to their size. They are typically between one nanometer (mm) and100nm in size. One nanometer is on-billionth of a meter. The relative scale can be judged from the statement that a nanometer is of about the same proportion to a meter, as a marble is to the earth.
The emergence of this field was triggered by two major advances in the 1980s. The first was the development of the scanning tunneling microscope in the early 1981 which allowed images to be seen at the atomic level. The second was a serendipitous discovery of molecular “carbon footballs” in 1985 by Harry Kroto, Richard Smalley, and Robert Curl, who together won the 1996 Nobel Prize In Chemistry. A host of developments followed carbon nanotubes, thin carbon sheaths (grapheme), and different methods to develop useful nanomaterials.
The applications in medicine include improved drug delivery of nanomedicines due to improved absorption in the human body. Their use in medical imaging can provide better pictures of cancerous tissues. Suitably engineered nanoparticles can deliver drugs, heat, light, and other materials only to diseased cells without damanging healthy tissues. In the field of electronics, lighter display screens have been developed that consume less power, including flexible display panels made from nanowires. High density memory chips and much smaller transistors used in integrated circuits are being developed so that much smaller and more efficient computers can be produced. The marked size of nanoelectronics is presently estimated to be above $4 trillion.
In food science, nanotechnology is finding applications on improved methods to grow and store food. Silver nanoparticles have been incorporated in plastic storage bins so that harmful bacteria are killed on contact. Zinc oxide nonoparticles incorportated into packaging plastic films block Uv light, and provide anti-bacterial protection while making the films stronger and increasing their stability. Pesticides incorporated in nanocapsules release the toxic materials only in the stomach of insects that consume them, thereby protection the plants (and us) from their harmful effects.
Nanosensors are being developed that recognize when individual plants need water, fertilizers or nutrient and trigger their release as and when needed, thereby optimizing the growth of each plant and reducing the consumption of water, nutrients and fertilizers. Nanofood products are estimated to have a market size of about $20 billion.
Other applications of nanotechnology include the development of bulletproof paper made from nanocellulose which is stronger than steel, new light weight and stronger materials used in space craft and aeroplanes, and longer lasting light weight batteries. Nanotechnology has also been used for the economical production of stronger light weight textiles, tennis racquets and other sports goods. Textiles using nanotechnology are estimated to have a market size of $115 billion.
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