28-05-2012, 10:15 AM
NANOTECHNOLOGY: AN OVERVIEW
NANOTECHNOLOGY AN OVERVIEW.doc (Size: 220.5 KB / Downloads: 27)
Nanotechnology is the manipulation of matter on the nanoscale. A nanometer is a very small measure of length-it is one billionth of a meter, a length so small that only three or four atoms lined up in a row would be a nanometer. So, nanotechnology involves designing and building materials and devices where the basic structure of the material or device is specified on the scale of one or a few nanometers. Ultimately, nanotechnology will mean materials and devices in which every atom is assigned a place, and having every atom in the right place will be essential for the functioning of the device.
The kinds of product that could be built will range from microscopic, very powerful computers to super strong materials ten times as strong as steel, but much lighter too, food to other biological tissues. All these products would be very inexpensive because the molecular machines that built them will basically take atoms from garbage or dirt, and energy from sunshine, and rearrange those atoms into useful products, just like trees and crops take dirt, water and sunshine and rearrange the atoms into wood and food.
. MECHANICAL ENGINEERING AND NANOTECHNOLOGY - THE COMMON CHORD
The mechanical applications of nanotechnology are immense as it is in any other technological field. This paper concentrates on certain applications of interest viz. Carbon Nanotubes, Nanomachines and other related fields.
Carbon nanotubes are cylindrical molecules with dimensions in the range of nanometers. They are constituted of carbon atoms only, and can essentially be thought of as a layer of graphite rolled-up into a cylinder. They have an impressive list of attributes. They can behave like metals or semiconductors, can conduct electrically better than copper, can transmit heat better than diamond, and they rank among the strongest materials known- not bad for structures that are just a few nanometers across. Several decades from now we may see integrated circuits with components and wires made from nanotubes and may be even buildings that can snap back into shape after an earthquake.
Nanomachines are extremely small machines which are built from individual atoms. During the 1980’s and 1990’s, futurist and visionary K.Eric Drexler popularized the potential of nanomachines. ‘Nanomachines’ include replicas of present day machines(nanogears,nanopumps etc as well as new machines that do not have analog in the present world, like the assembler. The assembler is a nanomachine designed to manipulate matter as the atomic level.
. CARBON NANOTUBES
In 1991, a Japanese scientist Sumio Iijima used a high-resolution transmission electron microscope to study the soot created in an electrical discharge between two carbon electrodes at the NEC Fundamental Research Laboratory in Tsukuba, Japan. He found that the soot contained structures that consisted of several concentric tubes of carbon, nested inside each like Russian dolls. These were termed as ‘Carbon Nanotubes’.
Later efficient ways of making large quantities of these multiwall nanotubes were developed. Subsequently, 1993, single-wall nanotubes were tens of nanometers across, the typical diameter of a single-wall nanotube was just one or two nanometers. The past decade has seen an explosion of research into both types of nanotube.
Today, nanotubes can be grown efficiently by the catalytic decomposition of a reaction gas that contains carbon, with iron often being used as the catalyst. This process has two main advantages. First, the nanotubes are obtained at much lower temperature, although this is at the cost of lower quality. Second, the catalyst can be grown on a substrate, which allows novel structures, such as ‘nanobrushes’, to be obtained. Currently nanotubes can be grown to lengths exceeding 100 microns, and in various shapes such as ‘nanosprings’.
. CONCLUSION
All the applications mentioned in this paper exhibit a wealth of properties and phenomena. While many of these are understood, others remain controversial, and all these fields are sure to remain an exciting area of science for years to come. The amazing predictions discussed are not in doubt. Like any new technology, however many of these have to outperform current technologies to gain a foothold. All these challenges will keep researchers busy for a long time to come.
NANOTECHNOLOGY AN OVERVIEW.doc (Size: 220.5 KB / Downloads: 27)
Nanotechnology is the manipulation of matter on the nanoscale. A nanometer is a very small measure of length-it is one billionth of a meter, a length so small that only three or four atoms lined up in a row would be a nanometer. So, nanotechnology involves designing and building materials and devices where the basic structure of the material or device is specified on the scale of one or a few nanometers. Ultimately, nanotechnology will mean materials and devices in which every atom is assigned a place, and having every atom in the right place will be essential for the functioning of the device.
The kinds of product that could be built will range from microscopic, very powerful computers to super strong materials ten times as strong as steel, but much lighter too, food to other biological tissues. All these products would be very inexpensive because the molecular machines that built them will basically take atoms from garbage or dirt, and energy from sunshine, and rearrange those atoms into useful products, just like trees and crops take dirt, water and sunshine and rearrange the atoms into wood and food.
. MECHANICAL ENGINEERING AND NANOTECHNOLOGY - THE COMMON CHORD
The mechanical applications of nanotechnology are immense as it is in any other technological field. This paper concentrates on certain applications of interest viz. Carbon Nanotubes, Nanomachines and other related fields.
Carbon nanotubes are cylindrical molecules with dimensions in the range of nanometers. They are constituted of carbon atoms only, and can essentially be thought of as a layer of graphite rolled-up into a cylinder. They have an impressive list of attributes. They can behave like metals or semiconductors, can conduct electrically better than copper, can transmit heat better than diamond, and they rank among the strongest materials known- not bad for structures that are just a few nanometers across. Several decades from now we may see integrated circuits with components and wires made from nanotubes and may be even buildings that can snap back into shape after an earthquake.
Nanomachines are extremely small machines which are built from individual atoms. During the 1980’s and 1990’s, futurist and visionary K.Eric Drexler popularized the potential of nanomachines. ‘Nanomachines’ include replicas of present day machines(nanogears,nanopumps etc as well as new machines that do not have analog in the present world, like the assembler. The assembler is a nanomachine designed to manipulate matter as the atomic level.
. CARBON NANOTUBES
In 1991, a Japanese scientist Sumio Iijima used a high-resolution transmission electron microscope to study the soot created in an electrical discharge between two carbon electrodes at the NEC Fundamental Research Laboratory in Tsukuba, Japan. He found that the soot contained structures that consisted of several concentric tubes of carbon, nested inside each like Russian dolls. These were termed as ‘Carbon Nanotubes’.
Later efficient ways of making large quantities of these multiwall nanotubes were developed. Subsequently, 1993, single-wall nanotubes were tens of nanometers across, the typical diameter of a single-wall nanotube was just one or two nanometers. The past decade has seen an explosion of research into both types of nanotube.
Today, nanotubes can be grown efficiently by the catalytic decomposition of a reaction gas that contains carbon, with iron often being used as the catalyst. This process has two main advantages. First, the nanotubes are obtained at much lower temperature, although this is at the cost of lower quality. Second, the catalyst can be grown on a substrate, which allows novel structures, such as ‘nanobrushes’, to be obtained. Currently nanotubes can be grown to lengths exceeding 100 microns, and in various shapes such as ‘nanosprings’.
. CONCLUSION
All the applications mentioned in this paper exhibit a wealth of properties and phenomena. While many of these are understood, others remain controversial, and all these fields are sure to remain an exciting area of science for years to come. The amazing predictions discussed are not in doubt. Like any new technology, however many of these have to outperform current technologies to gain a foothold. All these challenges will keep researchers busy for a long time to come.