29-05-2012, 03:43 PM
NanoTechnology
NANOTECHNOLOGY.docx (Size: 368.32 KB / Downloads: 69)
INTRODUCTION
In a world of information, digital technologies have made copying fast, cheap, and perfect, quite, independent of cost or complexity of the content. What if the same were to happen in the world of matter? The production cost of a ton of tetra byte RAM chips would be about the same as the production cost of steel. Design costs matter, production costs would not matter.
Hard to imagine? Not for the new breed of scientist who says that the 21st century could see all these science fiction dreams come true that is because of molecular nanotechnology, a hybrid of chemistry and engineering that would let us manufacture anything with atomic precision. Nanotechnology at times becomes easier to predict.
Nanotechnology can best be considered as a 'catch-all' description of activities at the level of atoms and molecules that have applications in the real world.
Nanotechnology is the creation of functional materials, devices and systems through control of matter on the nanometer length scale (1-100 nanometers), and exploitation of novel phenomena and properties (physical, chemical, biological, mechanical, electrical...) at that length scale. For comparison, 10 nanometers is 1000 times smaller than the diameter of a human hair. A scientific and technical revolution has just begun based upon the ability to systematically organize and manipulate matter at nanoscale.
The term sometimes applies to any microscopic technology. Due to the small size at which nanotechnology operates, physical phenomena not observed at the macroscopic scale dominate. These nanoscale phenomena include quantum size effects and short range forces such as vander waals forces. Furthermore the vastly increased ratio of surface area to volume promotes surface phenomena. Since the progress of computers is growing expotentially it is believed that it will develop into nanotechnology in the near future. Just as computers break down data into its most basic form 1’s and 0’s—
nanotechnology deals with matter in its most elemental form: atoms and molecules.
With a computer, once data is broken down and organized into combinations of 1s and 0s, it can be easily reproduced and distributed. With matter, the basic building blocks are atoms and the combinations of atoms that make up molecules. Nanotechnology lets you manipulate those atoms and molecules, making it possible to manufacture, replicate, and distribute any substance known to humans as easily and cheaply as you can replicate data on a computer.In fiction and media, "nanotechnology" often refers to hypothetical molecular nanotechnology (also known as "MNT").
HISTORY
The first mention of nanotechnology (not yet using that name) occurred in a talk given by Richard Feynman in 1959, entitled “There’s plenty of Room at the Bottom”. Feynman suggested a means to develop the ability to manipulate atoms and molecules "directly", by developing a set of one-tenth-scale machine tools analogous to those found in any machine shop. As the sizes get smaller, we would have to redesign some tools because the relative strength of various forces would change. Gravity would become less important, surface tension would become more important, Van der Waals attraction would become important, etc. Feynman mentioned these scaling issues during his talk. Nobody has yet effectively refuted the feasibility of his proposal.
HOW WILL NANO TECHNOLOGY CHANGE THE WORLD
FIRST BRICKS THEN THE BUILDING
Before nanotechnology can become anything other than a very impressive computer simulation, nanotechnologists are inventing an assembler, few-atoms-large nanomachines that can custom-build matter.
Engineers at Cornell and Stanford, as well as at Zyvex (the self- described "first molecular nanotechnology development company") are working to create such assemblers right now.
The first products will most likely be superstrong nanoscale building materials, such as the Buckytubes. Fullerenes, or buckminsterfullerenes in full, are molecules composed entirely of carbon, taking the form of a hollow sphere, ellipsoid, tube, or ring. They are sometimes called buckyballs or buckytubes, depending on the shape.
Bucky tubes are chicken-wire-shaped tubes made from geodesic dome-shaped carbon molecules. These tubes are essentially nanometer-sized graphite fibers, and their strength is 100 to 150 times that of steel at less than one-fourth the weight. Fullerenes are similar in structure to graphite, which is composed of a sheet of linked hexagonal rings, but they contain pentagonal (or sometimes heptagonal) rings that prevent the sheet from being planar. Cylindrical fullerenes are often called nanotubes. The smallest fullerene in which no two pentagons share an edge (which is destabilizing — see pentalne) is C60, and as such it is also the most common. A common method used to produce fullerenes is to send a large current between two nearby graphite electrodes in an inert atmosphere. The resulting carbon plasma arc between the electrodes cools into sooty residue from which many fullerenes can be isolated.
The key to manufacturing with assemblers on a large scale is self-replication. One nano-sized robot making wood one nano-sized piece at a time would be painfully slow. But if these assemblers could replicate themselves, we could have trillions of assemblers all manufacturing in unison. Then there would be no limit to the kinds of things we could create. "Not only will our manufacturing process be transformed, but our concept of labor. Consumer goods will become plentiful, inexpensive, smart, and durable".
.CARBON NANOTUBE:
An electronic device known as a diode can be formed by joining two nanoscale carbon tubes with different electronic properties.
Carbon nanotubes are tubular carbon molecules with properties that make them potentially useful in extremely small scale electronic and mechanical applications. They exhibit unusual strength and unique electrical properties, and are extremely efficient conductors of heat.
A nanotube has a structure similar to a fullerene, but where a fullerene's carbon atoms form a sphere, a nanotube is cylindrical and each end is typically capped with half a fullerene molecule. Their name derives from their size; nanotubes are on the order of only a few nonometers wide (on the order of one ten-thousandth the width of a human hair), and their length can be millions of times greater than their width.
Nanotubes are composed entirely of sp2 bonds, similar to graphite. Stronger than the sp3 bonds found in diamond, this bonding structure provides them with their unique strength. Nanotubes naturally align themselves into "ropes" held together by Van der Waals force . Under high pressure, nanotubes can merge together, trading some sp2 bonds for sp3 bonds, giving great possibility for producing strong, unlimited-length wires through high-pressure nanotube linking.
.NANOWIRE:
A"nanowire" is a wire of dimensions of the order of a nanometer (10 - 9 meters). The nanowires could be used, in a near feature, as components of nanotechnology to create electrical circuits out of compounds that are capable of being formed into extremely small circuits. Nanowires are not observed spontaneously in nature and must be produced in a laboratory. Nanowires can be either suspended or deposited.
USE OF NANOWIRES:
To create active electronic elements, the first key step was to chemically dope a semiconductor nanowire. This has already been done to individual nanowires to create p-type and n-type semicondcutors.
NANOTECHNOLOGY.docx (Size: 368.32 KB / Downloads: 69)
INTRODUCTION
In a world of information, digital technologies have made copying fast, cheap, and perfect, quite, independent of cost or complexity of the content. What if the same were to happen in the world of matter? The production cost of a ton of tetra byte RAM chips would be about the same as the production cost of steel. Design costs matter, production costs would not matter.
Hard to imagine? Not for the new breed of scientist who says that the 21st century could see all these science fiction dreams come true that is because of molecular nanotechnology, a hybrid of chemistry and engineering that would let us manufacture anything with atomic precision. Nanotechnology at times becomes easier to predict.
Nanotechnology can best be considered as a 'catch-all' description of activities at the level of atoms and molecules that have applications in the real world.
Nanotechnology is the creation of functional materials, devices and systems through control of matter on the nanometer length scale (1-100 nanometers), and exploitation of novel phenomena and properties (physical, chemical, biological, mechanical, electrical...) at that length scale. For comparison, 10 nanometers is 1000 times smaller than the diameter of a human hair. A scientific and technical revolution has just begun based upon the ability to systematically organize and manipulate matter at nanoscale.
The term sometimes applies to any microscopic technology. Due to the small size at which nanotechnology operates, physical phenomena not observed at the macroscopic scale dominate. These nanoscale phenomena include quantum size effects and short range forces such as vander waals forces. Furthermore the vastly increased ratio of surface area to volume promotes surface phenomena. Since the progress of computers is growing expotentially it is believed that it will develop into nanotechnology in the near future. Just as computers break down data into its most basic form 1’s and 0’s—
nanotechnology deals with matter in its most elemental form: atoms and molecules.
With a computer, once data is broken down and organized into combinations of 1s and 0s, it can be easily reproduced and distributed. With matter, the basic building blocks are atoms and the combinations of atoms that make up molecules. Nanotechnology lets you manipulate those atoms and molecules, making it possible to manufacture, replicate, and distribute any substance known to humans as easily and cheaply as you can replicate data on a computer.In fiction and media, "nanotechnology" often refers to hypothetical molecular nanotechnology (also known as "MNT").
HISTORY
The first mention of nanotechnology (not yet using that name) occurred in a talk given by Richard Feynman in 1959, entitled “There’s plenty of Room at the Bottom”. Feynman suggested a means to develop the ability to manipulate atoms and molecules "directly", by developing a set of one-tenth-scale machine tools analogous to those found in any machine shop. As the sizes get smaller, we would have to redesign some tools because the relative strength of various forces would change. Gravity would become less important, surface tension would become more important, Van der Waals attraction would become important, etc. Feynman mentioned these scaling issues during his talk. Nobody has yet effectively refuted the feasibility of his proposal.
HOW WILL NANO TECHNOLOGY CHANGE THE WORLD
FIRST BRICKS THEN THE BUILDING
Before nanotechnology can become anything other than a very impressive computer simulation, nanotechnologists are inventing an assembler, few-atoms-large nanomachines that can custom-build matter.
Engineers at Cornell and Stanford, as well as at Zyvex (the self- described "first molecular nanotechnology development company") are working to create such assemblers right now.
The first products will most likely be superstrong nanoscale building materials, such as the Buckytubes. Fullerenes, or buckminsterfullerenes in full, are molecules composed entirely of carbon, taking the form of a hollow sphere, ellipsoid, tube, or ring. They are sometimes called buckyballs or buckytubes, depending on the shape.
Bucky tubes are chicken-wire-shaped tubes made from geodesic dome-shaped carbon molecules. These tubes are essentially nanometer-sized graphite fibers, and their strength is 100 to 150 times that of steel at less than one-fourth the weight. Fullerenes are similar in structure to graphite, which is composed of a sheet of linked hexagonal rings, but they contain pentagonal (or sometimes heptagonal) rings that prevent the sheet from being planar. Cylindrical fullerenes are often called nanotubes. The smallest fullerene in which no two pentagons share an edge (which is destabilizing — see pentalne) is C60, and as such it is also the most common. A common method used to produce fullerenes is to send a large current between two nearby graphite electrodes in an inert atmosphere. The resulting carbon plasma arc between the electrodes cools into sooty residue from which many fullerenes can be isolated.
The key to manufacturing with assemblers on a large scale is self-replication. One nano-sized robot making wood one nano-sized piece at a time would be painfully slow. But if these assemblers could replicate themselves, we could have trillions of assemblers all manufacturing in unison. Then there would be no limit to the kinds of things we could create. "Not only will our manufacturing process be transformed, but our concept of labor. Consumer goods will become plentiful, inexpensive, smart, and durable".
.CARBON NANOTUBE:
An electronic device known as a diode can be formed by joining two nanoscale carbon tubes with different electronic properties.
Carbon nanotubes are tubular carbon molecules with properties that make them potentially useful in extremely small scale electronic and mechanical applications. They exhibit unusual strength and unique electrical properties, and are extremely efficient conductors of heat.
A nanotube has a structure similar to a fullerene, but where a fullerene's carbon atoms form a sphere, a nanotube is cylindrical and each end is typically capped with half a fullerene molecule. Their name derives from their size; nanotubes are on the order of only a few nonometers wide (on the order of one ten-thousandth the width of a human hair), and their length can be millions of times greater than their width.
Nanotubes are composed entirely of sp2 bonds, similar to graphite. Stronger than the sp3 bonds found in diamond, this bonding structure provides them with their unique strength. Nanotubes naturally align themselves into "ropes" held together by Van der Waals force . Under high pressure, nanotubes can merge together, trading some sp2 bonds for sp3 bonds, giving great possibility for producing strong, unlimited-length wires through high-pressure nanotube linking.
.NANOWIRE:
A"nanowire" is a wire of dimensions of the order of a nanometer (10 - 9 meters). The nanowires could be used, in a near feature, as components of nanotechnology to create electrical circuits out of compounds that are capable of being formed into extremely small circuits. Nanowires are not observed spontaneously in nature and must be produced in a laboratory. Nanowires can be either suspended or deposited.
USE OF NANOWIRES:
To create active electronic elements, the first key step was to chemically dope a semiconductor nanowire. This has already been done to individual nanowires to create p-type and n-type semicondcutors.