Applications of Nanotechnology
Nanotechnology has found wide-ranging applications in many fields. There are following some of the important applications discussed below.
1) Electronics: Nanosized electronic components show unique properties which are different from the larger semiconductor components. The semiconductor devices are based on the concept of charge transport only whereas the nanosized components work on the concept of charge as well as spin transport of electrons. This has been used in devices like spin FET, Spin LED etc. These devices have increased the data storage capacities of hard disks and have led to small and faster microprocessors.
2) Energy: Attempts are being made to increase the efficiency of solar cells by using nanotechnology. Another important area of research is the use of hydrogen as a fuel. The main problem with hydrogen is that it is highly combustible and hence cannot be stored easily. Efforts are being made to use carbon nanotubes to trap and store hydrogen. Nanoparticles are also being used to increase the energy density of rechargeable batteries which are used in laptops and mobile phones.
3) Automobiles: Nanotube composites have better mechanical strength compared to steel but are costly at present. Efforts are being made to develop cheaper nanotube composites that can replace steel which is used to construct the body structure of automobiles. The use of nanoparticles in paints provides thin and smooth coatings. Nanoparticles are being used to develop lightweight and less rubber-consuming tyres for automobiles which will increase the mileage of the automobiles. The use of carbon nanotubes for storing hydrogen is being explored so that automobiles can be run on hydrogen
as a fuel. Nanomaterial catalysts can be used as catalysts to convert the harmful emissions from automobiles to less harmful gases.
4) Space and defence: Aerogels are porous materials with nanosized pores. They have very low density and are poor conductors of heat. They can be used in spacecraft, lightweight suits and jackets. Polymer composites using silica fibres and nanoparticles have larger mechanical strength and low-temperature coefficient of expansion. They can be used in spacecrafts which have to withstand high temperature and stress conditions during launching and
re-entry into the earth's atmosphere. Satellites and spacecrafts use solar energy. The efficiency of solar cells can be increased using nanoparticles. The use of nanoparticles will also make the solar cells smaller in size and lightweight.
5) Medical: Nanoparticles can be used for the detection and treatment of cancers and tumours. The nanoparticles are injected into the body and guided towards a specific part. Drugs can be encapsulated in nanocapsules and guided towards any specific part where the drug can be delivered in a controlled manner by opening the capsule at a desired rate using magnetic fields or infrared light. This targeted drug delivery does not affect healthy organs. Nanotechnology-based tests are being developed for fast
detection of viruses and antibodies.
6) Environmental: Nanoparticle-based sensors are capable of detecting water and air pollution due to toxic ions and pesticides with a very high sensitivity. Nanomaterial catalysts can be used as catalysts to convert the harmful emissions from industries and automobiles to less harmful gases.
Nanotubes can be used to store hydrogen fuel which, when used in automobiles, will reduce harmful emissions.
7) Textiles: The use of nanotechnology in the textile industry has led to the development of water-repellent and wrinkle-free clothes.
8) Cosmetics: Zinc oxide and titanium oxide nanoparticles are used in sunscreen lotions which protect the skin from ultraviolet radiation. These nanoparticles absorb ultraviolet radiation. Nanoparticle-based dyes and colours are harmless to the skin and
hence are used in hair creams, gels and hair dyes.
