Applications of nanotubes

Unusual electrical properties of nanotubes will make them one of the main materials of nanoelectronics. On their basis prototypes of new elements for computers are made. These elements provide a reduction of devices in comparison with silicon ones by several orders of magnitude. And nanotubes are given an unquestionably leading position among prospective candidates for the place of silicon.

Another use of nanotubes in nanoelectronics is the creation of semiconductor heterostructures, i.e. structures such as "metal / semiconductor" or the junction of two different semiconductors (nanotransistors). To do this, it is necessary to create a structural defect in the nanotube growth process (namely, to replace one of the carbon hexagons with a pentagon) by simply breaking it in the middle in a special way. Then one part of the nanotube will have metallic properties, and the other will have the properties of semiconductors.

Several applications of nanotubes in the computer industry have been developed. Under the influence of the voltage applied to one of the ends of the nanotube, the other end begins to emit electrons that fall on the phosphorescent screen and cause illumination. The resultant grain of the image will be fantastically small: of the order of a micron.

Due to their superior electrical properties carbon nanomaterials such as one-dimensional (1D) carbon nanotubes and two-dimensional (2D) graphene are evolving as significant tools which provide a faster and more power-efficient electronics. In addition, high surface to volume ratio, robust and durable mechanical properties have established them a highly sensitive and lower energy consuming building block for nano sensors. All the carbon nanotubes have an ability to emit electrons in the presence of an electric field. This property has been utilized in the field emission devices like television, computer screens and other instruments which are based on cathode-ray emission. Nanotechnology is facilitating the production of brighter, clearer and more efficient displays for computers and television.

The chemical and physical state of the environment may alter the electrical conductivity of carbon nanotubes and thus carbon nanotubes have been developed as chemical and physical sensors. The efficiency of carbon nanotubes to detect any changes in chemical composition of the environment is three times higher in magnitude than conventional solid state sensors. The other advantage of these electronic chips is that they are smaller in size and can be used at room temperature.

Another example is the use of a nanotube as a needle for a scanning microscope. Usually such a point is an acute sharpened tungsten needle, but according to atomic standards such sharpening is still quite rough. Nanotube is an ideal needle with a diameter of the order of several atoms. Applying a certain voltage, you can pick up the atoms and whole molecules that are on the substrate directly under the needle, and carry them from place to place.