Nano-RAM is a proprietary computer memory technology from the company. Nantero and NANOMOTOR is invented by University of bologna and California. (RAM) is a type of data storage used in computers. It takes the form of integrated circuits that allow the stored data to be accessed in any order accessed in any. Abstract— NRAM (Nano Random Access Memory), is one of the important applications of .. ryaleomitsuvi.tk- ryaleomitsuvi.tk%20GSA%20Article. pdf.
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Nano-RAM is a proprietary computer memory technology from the company Nantero. It is a type . Archived from the original (PDF) on Retrieved . Seminar Report of Nano-ram - Free download as Word Doc .doc /.docx), PDF File .pdf), Text File .txt) or read online for free. report on nano ram. Nano RAM Abstract - Download as Powerpoint Presentation .ppt /.pptx), PDF File .pdf), Text File .txt) or view presentation slides online. It is abstract about.
This means that NRAM might compete with DRAM in terms of cost, but also require less power, and as a result also be much faster because write performance is largely determined by the total charge needed. The FG is surrounded by an insulating dielectric, typically an oxide.
Since the FG is electrically isolated by the surrounding dielectric, any electrons placed on the FG will be trapped on the FG which screens the CG from the channel of the transistor and modifies the threshold voltage VT of the transistor.
The current flowing through the MOSFET channel is sensed to determine the state of the cell forming a binary code where a 1 state current flow when an appropriate CG voltage is applied and a 0 state no current flow when the CG voltage is applied. After being written to, the insulator traps electrons on the FG, locking it into the 0 state.
However, in order to change that bit, the insulator has to be "overcharged" to erase any charge already stored in it. This requires higher voltage, about 10 volts, much more than a battery can provide. Flash systems include a " charge pump " that slowly builds up power and releases it at higher voltage.
This process is not only slow, but degrades the insulators. For this reason flash has a limited number of writes before the device will no longer operate effectively. It may also be much faster to write than either, meaning it may be used to replace both. Modern phones include flash memory for storing phone numbers, DRAM for higher performance working memory because flash is too slow, and some SRAM for even higher performance.
The state of the field in the material encodes the bit in a non-destructive format. FeRAM is used in applications where the limited number of writes of flash is an issue. FeRAM read operations are destructive, requiring a restoring write operation afterwards. Vaanderwaals forces interaction between atoms that enable noncovalant binding.
They rely on electron attractions that arise only at nano scale levels as a force to be reckoned with. The company is using this property in its design to integrate nanoscale material property with established cmos fabrication technique. Under differing electric charges, the tubes can be physically swung into one or two positions representing one and zeros.
Because the tubes are very small-under a thousands of time-this movement is very fast and needs very little power, and because the tubes are a thousand times conductive as copper it is very to sense to read back the data.
Once in position the tubes stay there until a signal resets them. The bit itself is not stored in the nano tubes, but rather is stored as the position of the nanotube.
Up is bit 0 and down is bit 1. Bits are switched between the states by the application of the electric field. The technology work by changing the charge placed on a latticework of crossed nanotube.
By altering the charges, engineers can cause the tubes to bind together or separate, creating ones and zeros that form the basis of computer memory. If we have two nano tubes perpendicular to each other one is positive and other negative, they will bend together and touch.
If we rearrange the atoms in sand and add a few other trace elements we can make computer chips. If we rearrange the atoms in dirt, water and air, we can make potatoes.
There are two more concepts commonly associated with Nanotechnology: Positional assembly Self replication Positional assembly refers to the arrangement of molecules so as to get the right molecular parts in the right places. The need for positional assembly implies an interest in molecular robotics e. These molecular scale positional devices are likely to resemble very small versions of their everyday macroscopic counterparts.
The self replicating systems are able both to make copies of themselves and to manufacture useful products. If we can design and build one such system the manufacturing costs for more such systems and the products they make assuming they can make copies of themselves in some reasonably inexpensive environment will be very low. You wont think about installing Microsoft Office anymore.
Youll think about growing software. The line is blurring in several ways. Scientists are learning to imitate biological patterns; biological entities are being used in technology products; and in the distant future, nanomachines may be circulating through our bloodstreams, attacking tumours and dispersing medicine. There are many others types of nanotubes, from various inorganic kinds such as, those made from boron nitride, to organic ones, such as those made from self-assembling cyclic peptides proteins components or from naturally occurring heat shock proteins extracted from bacteria that thrive in extreme environments.
However, carbon nanotubes excites the most interest, promise the greatest variety of application and currently appear to have by far the highest commercial potential.
Carbon nanotubes were discovered in by Sumio Iijima of NEC and are effectively long, thin cylinders of graphite, which you will be familiar with as the material in a pencil or as the basis of some lubricants. Graphite is made up of layers of carbon atoms arranged in a hexagonal lattice, like chicken wire. Though the chicken wire structure itself is very strong, the layers themselves sure not chemically bonded to each other but held together by weak forces called Vander Waals.
It is the sliding across each other of these layers that gives graphite its lubricating qualities and makes the mark on a piece of paper as you draw your pencil over it. Now imagine taking one of these sheets of chicken wire and rolling it up into a cylinder and joining the loose wore ends.
The result is a tube that was once described by Richard Smalley who shared the Nobel Prize for the discovery of a related form of carbon called buckminsterfullerene as nanotube. In one direction.
They can produce streams of electrons very efficiently field emission , which can be used to create light in displays for televisions or computers, or even in domestic lighting, and they can enhance the fluorescence of materials they are close to.
Their electrical properties can be made to change in the presence can act like miniature springs and they can even be stuffed with other material. Nanotubes and their variants hold promise for storing fuels such as hydrogen or methanol for use in fuel cells and they make good support for catalysts.
Nanotubes have been constructed with length-to-diameter ratio of up to ,, They exhibit extraordinary strength and.
The nature of the bonding of a nanotube is described by applied quantum chemistry, specifically, orbital hybridization.
The chemical bonding of nanotubes is composed entirely of sp2 bonds, similar to those of graphite. This bonding structure, which is stronger than the sp3 bonds found in diamonds, provides the molecules with their unique strength. Nanotubes naturally align themselves into "ropes" held together by Van der Waals forces. Since carbon nanotubes were discovered on accident by Sumio Iijima in during another experiment, hundreds of studies have been started and dedicated to achieving a better understanding of the structure of carbon nanotubes.
Although the structure of carbon nanotubes has been extensively studied by researchers and scientists in a wide variety of fields including materials science, architecture, agriculture and engineering, the full implications of this tiny microscopic wonder are still locked away in its unique natural creation, varied structural components and its ability to be both immensely flexible as well as incredibly strong.
Carbon comes in many forms. Two well-known forms of carbon are graphite and diamond. Graphite and diamond have drastically different mechanical properties such as hardness. Diamond is one of the hardest materials known to man. It can cut through glass. The difference in properties is due to the structure of the atoms and their bonds in the material, also known as the materials crystal structure. Graphite is made up of stacked sheets of hexagons with a carbon atom at each corner of the hexagon, and looks much like chicken wire.
These sheets are stacked one on top of the other, but easily slip and slide. Diamond has a tetragonal crystal structure with very few slip planes.
Carbon nanotubes are a fairly new form of carbon. A carbon nanotube structure looks like sheets of graphite that have been rolled up to form small tubes. This small difference in structure leads to a much stronger, stiffer material. Carbon nanotubes have a diameter of 1 to 10 nanometers, yet they are 50 times stronger than steel. The special nature of carbon combines with the molecular perfection of buckytubes singlewall carbon nanotubes to endow them with exceptionally high material properties such as electrical and thermal conductivity, strength, stiffness, and toughness.
The delocalised pi-electron donated by each atom is free to move about the entire structure, rather than stay home with its donor atom, giving rise to the first molecule with metallic-type electrical conductivity. The high-frequency carbon-carbon bond vibrations provide an intrinsic thermal conductivity higher than even diamond.
In most materials, however, the actual observed material properties - strength, electrical conductivity, etc. Buckytubes, however, achieve values very close to their theoretical limits because of their perfection of structure - their molecular perfection.
This aspect is part of the unique story of buckytubes. Buckytubes are an example of true nanotechnology: They open incredible applications in materials, electronics, chemical processing and energy management. Graphene consists of a hexagonal structure like chicken wire. If you imagine rolling up graphene or chicken wire into a seamless tube, this can be accomplished in various ways. For example, carboncarbon bonds the wires in chicken wire can be parallel or perpendicular to the tube axis, resulting in a tube where the hexagons circle the tube like a belt, but are oriented differently.
Alternatively, the carbon-carbon fig 3. Fig 7 illustrates these point. Carbon nanotubes appear to be sheets of graphite cells that have been mended together to look almost like a latticework fence and then rolled up in a tube shape. Although this is a simple explanation for the look of the structure of carbon nanotubes, this is not how carbon nanotubes are created, nor does it explain their immense strength or other incredible structural abilities.
The length of both type vary greatly, depending upon on the way they are made and are generally nanoscopic rather than microscopic i.
The aspect ratio length divided by diameter is typically greater than and can be up to 10,, but recently even this was made to look small. Even more recently, the same group has made strand of SWNTs cm long, but the precise make up of these strand has not yet been made clear.
A group in china has found, purely by accident that packs of relatively short carbon nanotubes can be drawn out into a bundle of fibers, making a thread only 0. The joins between the nanotubes in this thread represent a weakness but heating the thread has been found to increase the strength significantly, presumably through some sort of fusing of the individual tubes.
They have a single cylindrical wall. The structure of a SWNT can be visualized as a layer of graphite, a single atom thick, called graphene, which is rolled into a seamless cylinder. Most SWNT typically have a diameter of close to 1 nm. The tube length, however, can be many thousands of times longer. MWNTs are typically times longer than they are wide and have outer diameter mostly in the tens of nanometer.
Multitudes of exotic shapes and arrangement, often with imaginative names such as bamboo-trunks, sea urchins etc. There is as yet no good way to remove the heat produced by the devices, so packing them in more tightly will only lead to rapid overheating. As metal wires get smaller, the gust of electrons moving through them becomes strong enough to bump the metal atoms around and before long, the wires fail like blown fuses.
In theory, nanotubes could solve both these problems. Scientists have predicted that carbon nanotubes would conduct heat nearly as well as diamond or sapphire and preliminary experiments seem to confirm their prediction. So nanotubes could efficiently cool very dense arrays of devices. As bonds among carbon atoms are so much stronger than those in any metal, nanotubes can transport terrific amount of electric current the latest measurements show that a bundle of nanotubes one square centimeter in cross section could conduct about one billion amps.
Such high currents would vaporize copper or gold. When stood on end and electrified, carbon nanotubes will act just as lightning rods do, concentrating the electrical field at their tips. Their strong carbon bonds allow nanotubes to operate for longer periods without damage. The scientists have found ways to grow clusters of upright nanotubes in neat little grids.
At optimum density, such clusters can emit more than one amp per square centimetre, which is more than sufficient to light up the phosphers on a screen and is even powerful enough to drive microwave relays and high-frequency switches in cellular phones. Ise Electronics in Ise, Japan, has used nanotube composite to make prototype vaccum-tube lamps in six colours that are twice as bright as conventional lightbulbs, longer-lived and atleast 10 times more energy efficient.
The first prototype has run for well over 10, hours and has yet to fail. Engineers at Samsung in Seol stread nanotubes in a thin film over control electronics and then put phosphor-coated glass on top to make a prototype flat-pannel display. When they demonstrated the display last year, they were optimistic that the company would have the device-which will be as bright as a cathode-ray tube but it will consume one tenth as much power. And the product is on the market now.
In defect-free nanotubes, electrons travel ballistically-that is, without any of the scattering that gives metal wires their resistance. At the small size of a nanotube, the flow of electrons can be controlled with almost perfect precision. Scientists have recently demonstrated in nanotubes a phenomenon called Coulomb blockade, in which more than one electron at a time on to a nanotube. This phenomenon may make it easier to build single-electron transistors, the ultimate in sensitive electronics.
In diamond the carbon atoms link in to four-sided tetrahedral, but in nanotubes the atoms arrange themselves in hexagonal rings. In fact, a nanotube looks like a sheet or several stacked sheets of graphite rolled into a seamless cylinder.
Graphite itself is a very unusual material. Whereas most conductors can be classified as either metals or semiconductors, graphite is one of the rare materials known as semi metal, delicately balanced in the transitional zone between the two.
By combining graphite semi-metallic properties with the quantum rules of energy levels and electron waves, carbon nanotubes emerge as truly exotic conductor. One of the quantum worlds is that electrons behave like as well as particles, and electron waves can reinforce or cancel one another. As a consequence, an electron spreading around nanotubes circumference can completely cancel itself out; thus, only electrons with just the right wavelength remain.
Out of all the possible electron wavelengths, or quantum states, available in a flat graphite sheet, only a tiny subset is allowed when we roll that sheet into a nanotube. That subset depends on the circumference of the nanotube, as well as whether the nanotube twists.
In a graphite sheet, one particular electron state gives graphite almost all of its conductivity; none of the electrons in the other states are free to move about. These nanotubes are truly metallic nano wires. The remaining two third of the nanotubes are semiconductors. This means that, like silicon, they do not pass current easily without an additional boost of energy.
The burst of light or a voltage can knock electrons from valence states into conducting states where they can move about freely. The amount of energy needed depends on the separation between the two levels and is the so called band gap of a semiconductor. Carbon nanotubes dont all have the same band gap, because for every circumference there is a unique set of allowed valences and the conduction states.
The smallest diameter nanotubes have very few states that are spaced far apart in energy. As nanotube diameter increase, more and more states are allowed and the spacing between them shrinks. No other known material can be so easily tuned. A single walled nanotube is only one carbon atom thick. It can be considered as a sheet of graphite curled into the form of tube. Its properties can be changed by changing the direction of the curl.
It can be made highly conducting or semi-conducting based on the direction of the curl. A carbon nanotube is highly elastic. It can be made in the shape of a spring, brush or spiral. They have very low specific weight. Another very useful property of the nanotubes is that their high mechanical and tensile strength. A carbon nanotube can be made into a length of up to microns. They are chemically inert.
In near future it is possible that microprocessors may be converted into nanoprocessors. Nano-RAM is a proprietary computer memory technology from the company Nantero. It is a type of nonvolatile random access memory based on the mechanical position of carbon nanotubes deposited on a chip-like substrate. In other word a universal memory chip suitable for countless existing and new applications in the field of electronics. Nantero's technology is based on a well-known effect in carbon nanotubes where crossed nanotubes on a flat surface can either be touching or slightly separated in the vertical direction normal to the substrate due to Van der Waal's interactions.
In Nantero's technology, each NRAM "cell" consists of a number of nanotubes suspended on insulating "lands" over a metal electrode. At rest the nanotubes lie above the electrode "in the air", about 13 nm above it in the current versions, stretched between the two lands. A small dot of gold is deposited on top of the nanotubes on one of the lands, providing an electrical connection, or terminal.
A second electrode lies below the surface, about nm away. Normally, with the nanotubes suspended above the electrode, a small voltage applied between the terminal and upper electrode will result in no current flowing. This represents a "0" state.