ASEMINAR REPORT

ON

“NANORAM”

In partial fulfillment ofB.TECH IV Year (Computer Science & Engineering)

Department of Computer Science EngineeringJODHPUR INSTITUTE OF ENGINEERING & TECHNOLOGY

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Submitted To: Miss. Pooja Saxena Lecturer Computer Science & Engineering Department

Submitted By: Nitesh Kumar TaterComputer Science & Engg.IV Year

ACKNOWLEDGEMENT

With great pleasure and gratefulness, I extend my deep sense of gratitude to Miss.Pooja Saxena for giving me an opportunity to accomplish my seminar under her guidance and to increase my knowledge.

I also like to thanks Dr.Sugandha Singh (HEAD, Computer Science & Engineering, Jodhpur Institute of Engineering & Technology) for giving her precious time & guidance for the successful completion of my seminar.

I would express our sincere gratitude towards “Computer Science & Engineering Department, Jodhpur Institute of Engineering & Technology” for providing me excellent research facilities and state-of-the-art technology.

I am indebted to all our elders, lecturers and friends for inspiring me to do my seminar with immense dedication. Lastly I wish to thank each and every person involved in making my seminar successful.

Thank You.

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Nitesh Kumar TaterVIII Sem.CSE

PREFACE

Seminar is an important constituent of any curriculum and the B.TECH

course is no exception to this general rule. A seminar helps a student in increasing

his knowledge and confidence.

Seminar switches process of learning to process of presenting knowledge.

This provision offers a very good opportunity to the students to supplement their

knowledge and skills by giving presentation. This opportunity should be utilized for

developing and enhancing our skills.

This report describes in detail my seminar in B.TECH 4th year, on topic NANORAM.

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INDEX

1. Introduction…………..…………………………………………5

2. Nanotechnology ……..…………………………………………9

2.1 History …………………………………………9

2.2 Fundamental Concept…….…..…………….…10

2.3 Application ……..…………………………....10

3. Nano-Ram……………….………………………………….…18

3.1 Carbon Nano Tube …………….………………18

3.2 Technology…….…………………..…………..19

3.3 Design and Description………..………..……..20

4. Advantages ……………………….…………………………...23

5. Comparison with other proposed systems …………………….24

6. Limitation ………………………………….…………….........24

7. Application………………………………….……………..…..24

8. Conclusion…………………………….…….……………....…25

9. Keyword ………………………………………………...…….25

10. References & Bibliography………………………………..…...25

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1. INTRODUCTION:

Today the world is of digital. All the electronic devices are formalized to manipulate the digital data. The back -bone of today’s research and development “The Computer” is also a digital device. Digital by name deals with digits and all the gadgets available today (like PDA’s, laptops, etc…) need to manipulate the digital data. To manipulate first we have to store it at a place. Thus MEMORY in today’s world plays a key role and a constant research to improve the memory in today’s electronic gadgets is ON.

RAM (random access memory) is the main storage device in all digital systems. The speed of the system mainly depends on how speed and vast the RAM is. Today with increasing power need of man even the POWER consumed is also a major part to look at. By generations RAM also had under gone many changes. Some of the versions of RAM’s which are in use are DRAM, SRAM and FLASH MEMORY. DRAM (dynamic RAM) although has a capability to hold large amounts of data it is slower and volatile.

SRAM (static RAM) even superior to DRAM in speed but less denser. Even this is volatile in nature. Overcoming the volatile nature of these two FLASH MEMORY is the latest of today random access memories. Even this fails in power saving. Overcoming all these failures of above mentioned RAM’s , researchers developed a new RAM which unlike the semiconductor technology alone used by the former, uses a combination of NANOTECHNOLOGY and contemporary SEMICONDUCTOR TECHNOLOGY and isgiven the name NRAM.

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NANO + RAM

Greek prefix which means dwarf. In science this prefix denotes a fraction of 10-9 a given unit. For instance 1nm = 10-9m

Greek prefix which means dwarf. In science this prefix denotes a fraction of 10-9 a given unit. For instance 1nm = 10-9m

RAM (Random-Access Memory) is a form of computer data storage.

It takes the form of integrated circuits that allow stored volatile

data to be accessed in random order.

RAM (Random-Access Memory) is a form of computer data storage.

It takes the form of integrated circuits that allow stored volatile

data to be accessed in random order.

1.1 RAM (Random Access Memory):

It is a form of computer data storage. It takes the form of integrated circuits that allow stored volatile data to be accessed in random order. By contrast, storage devices such as magnetic discs and optical discs rely on the physical movement of the recording medium or a reading head. In these devices, the movement takes longer than data transfer, and the retrieval time varies based on the physical location of the next item.

The word RAM is often associated with volatile types of memory (such as DRAM memory modules), where the information is lost after the power is switched off. Many other types of memory are RAM, too, including most types of ROM and a type of flash memory called NOR Flash.

1.2 Types of RAM: There are mainly two types of RAM

1.2.1 DRAM:

Dynamic RAM is the most common type of memory in use today. Inside a dynamic RAM chip, each memory cell holds one bit of information and is made up of two parts: a transistor and a capacitor. These are, of course, extremely small transistors and capacitors so that millions of them can fit on a single memory chip. The capacitor holds the bit of information -- a 0 or a 1. The transistor acts as a switch that lets the control circuitry on the memory chip read the capacitor or change its state.

A capacitor is like a small bucket that is able to store electrons. To store a 1 in the memory cell, the bucket is filled with electrons. To store a 0, it is emptied. The problem with the capacitor's bucket is that it has a leak. In a matter of a few milliseconds a full bucket becomes empty. Therefore, for dynamic memory to work, either the CPU or the memory controller has to come along and recharge all of the capacitors holding a 1 before they discharge. To do this, the memory controller reads the memory and then writes it right back. This refresh operation happens automatically thousands of times per second.

This refresh operation is where dynamic RAM gets its name. Dynamic RAM has to be dynamically refreshed all of the time or it forgets what it is holding. The downside of all of this refreshing is that it takes time and slows down the memory.

1.2.2 SRAM:

Static RAM uses a completely different technology. In static RAM, a form of flip-flop holds each bit of memory. A flip-flop for a memory cell takes 4 or 6 transistors along with some wiring, but never has to be refreshed. This makes static RAM significantly faster than dynamic RAM. However, because it has more parts, a static memory cell takes a lot more space on a chip than a dynamic memory cell. Therefore you get less memory per chip, and that makes static RAM a lot more expensive. So static RAM is fast and expensive, and dynamic RAM is less expensive and

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slower. Therefore static RAM is used to create the CPU's speed-sensitive cache, while dynamic RAM forms the larger system RAM space.

There are some other types of RAM:

There are many different types of RAM which have appeared over the years and it is often difficult knowing the difference between them both performance wise and visually identifying them. This article tells a little about each RAM type, what it looks like and how it performs.

FPM RAMFPM RAM, which stands for Fast Page Mode RAM is a type of Dynamic RAM (DRAM). The term “Fast Page Mode comes from the capability of memory being able to access data that is on the same page and can be done with less latency. Most 486 and Pentium based systems from 1995 and earlier use FPM Memory.

FPM RAM

EDO RAMEDO RAM, which stands for “Extended Data Out RAM came out in 1995 as a new type of memory available for Pentium based systems. EDO is a modified form of FPM RAM which is commonly referred to as “Hyper Page Mode. Extended Data Out refers to fact that the data output drivers on the memory module are not switched off when the memory controller removes the column address to begin the next cycle, unlike FPM RAM. Most early Penitum based systems use EDO.

EDO RAM

SDRAMSDRAM , which is short for Synchronous DRAM is a type of DRAM that runs in synchronization with the memory bus. Beginning in 1996 most Intel based chipsets began to support SDRAM which made it a popular choice for new systems in 2001.SDRAM is capable of running at 133MHz which is about three times faster than FPM RAM and twice as fast as EDO RAM. Most Pentium or Celeron systems purchased in 1999 have SDRAM.

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SD RAM

DDR RAMDDR RAM, which stands for “Double Data Rate which is a type of SDRAM and appeared first on the market around 2001 but didn’t catch on until about 2001 when the mainstream motherboards started supporting it. The difference between SDRAM and DDR RAM is that instead of doubling the clock rate it transfers data twice per clock cycle which effectively doubles the data rate. DDRRAM has become mainstream in the graphics card market and has become the memory standard.

DDR RAM

Difference between DDR1,DDR2,DDR3 types of RAM?In computing, a computer bus operating with double data rate transfers data on both the rising and falling edges of the clock signal. This is also known as double pumped, dual-pumped, and double transition.DDR2 stores memory in memory cells that are activated with the use of a clock signal to synchronize their operation with an external data bus. Like DDR before it, DDR2 cells transfer data both on the rising and falling edge of the clock (a technique called "dual pumping"). The key difference between DDR and DDR2 is that in DDR2 the bus is clocked at twice the speed of the memory cells, so four words of data can be transferred per memory cell cycle. DDR3 memory comes with a promise of a power consumption reduction of 30% compared to current commercial DDR2 modules due to DDR3's 1.5 V supply voltage, compared to DDR2's 1.8 V or DDR's 2.5 V. This supply voltage works well with the 90 nm fabrication technology used for most DDR3 chips. Some manufacturers further propose to use "dual-gate" transistors to reduce leakage of current.The main benefit of DDR3 comes from the higher bandwidth made possible by DDR3's 8 bit deep prefetch buffer, whereas DDR2's is 4 bits, and DDR's is 2 bits deep.

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2. Nanotechnology

Nanotechnology, shortened to "nanotech", is the study of the controlling of matter on an atomic and molecular scale. Generally nanotechnology deals with structures of the size 100 nanometers or smaller in at least one dimension, and involves developing materials or devices within that size. Nanotechnology is very diverse, ranging from extensions of conventional device physics to completely new approaches based upon molecular self-assembly, from developing new materials with dimensions on the nanoscale to investigating whether we can directly control matter on the atomic scale.

There has been much debate on the future implications of nanotechnology. Nanotechnology has the potential to create many new materials and devices with a vast range of applications, such as in medicine, electronics and energy production. On the other hand, nanotechnology raises many of the same issues as with any introduction of new technology, including concerns about the toxicity and environmental impact of nanomaterials, and their potential effects on global economics, as well as speculation about various doomsday scenarios. These concerns have led to a debate among advocacy groups and governments on whether special regulation of nanotechnology is warranted.

Figure: Rotating view of Buckminster Fullerene C60.

2.1 History of Nanotechnology

The first use of the concepts found in 'nano-technology' (but pre-dating use of that name) was in "There's Plenty of Room at the Bottom," a talk given by physicist Richard Feynman at an American Physical Society meeting at Caltech on December 29, 1959. Feynman described a process by which the ability to manipulate individual atoms and molecules might be developed, using one set of precise tools to build and operate another proportionally smaller set, and so on down to the needed scale. In the course of this, he noted, scaling issues would arise from the changing magnitude of various physical phenomena: gravity would become less important, surface tension and van der Waals attraction would become increasingly more significant, etc. This basic idea appeared plausible, and exponential assembly enhances it with parallelism to produce a useful quantity of end products. The term "nanotechnology" was defined by Tokyo Science University Professor Norio Taniguchi in a 1974 paper as follows: "'Nano-technology'

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mainly consists of the processing of, separation, consolidation, and deformation of materials by one atom or by one molecule." In the 1980s the basic idea of this definition was explored in much more depth by Dr. K. Eric Drexler, who promoted the technological significance of nano-scale phenomena and devices through speeches and the books Engines of Creation: The Coming Era of Nanotechnology (1986) and Nanosystems: Molecular Machinery, Manufacturing, and Computation, and so the term acquired its current sense. Engines of Creation: The Coming Era of Nanotechnology is considered the first book on the topic of nanotechnology. Nanotechnology and nanoscience got started in the early 1980s with two major developments; the birth of cluster science and the invention of the scanning tunneling microscope (STM). This development led to the discovery of fullerenes in 1985 and carbon nanotubes a few years later. In another development, the synthesis and properties of semiconductor nanocrystals was studied; this led to a fast increasing number of metal and metal oxide nanoparticles and quantum dots. The atomic force microscope (AFM or SFM) was invented six years after the STM was invented. In 2000, the United States National Nanotechnology Initiative was founded to coordinate Federal nanotechnology research and development and is evaluated by the President's Council of Advisors on Science and Technology.

2.2 Fundamental concepts:-

One nanometer (nm) is one billionth, or 10−9, of a meter. By comparison, typical carbon-carbon bond lengths, or the spacing between these atoms in a molecule, are in the range 0.12–0.15 nm, and a DNA double-helix has a diameter around 2 nm. On the other hand, the smallest cellular life-forms, the bacteria of the genus Mycoplasma, are around 200 nm in length.

To put that scale in another context, the comparative size of a nanometer to a meter is the same as that of a marble to the size of the earth. Or another way of putting it: a nanometer is the amount a man's beard grows in the time it takes him to raise the razor to his face.

Two main approaches are used in nanotechnology. In the "bottom-up" approach, materials and devices are built from molecular components which assemble themselves chemically by principles of molecular recognition. In the "top-down" approach, nano-objects are constructed from larger entities without atomic-level control.

Areas of physics such as nanoelectronics, nanomechanics and nanophotonics have evolved during the last few decades to provide a basic scientific foundation of nanotechnology.

2.3 Application of Nanotechnology:-

2.3.1 Medicine

The biological and medical research communities have exploited the unique properties of nanomaterials for various applications (e.g., contrast agents for cell imaging and therapeutics for treating cancer). Terms such as biomedical nanotechnology, nanobiotechnology and nanomedicine are used to describe this hybrid field. Functionalities can be added to nanomaterials by interfacing them with biological molecules or structures.

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The size of nanomaterials is similar to that of most biological molecules and structures; therefore, nanomaterials can be useful for both in vivo and in vitro biomedical research and applications. Thus far, the integration of nanomaterials with biology has led to the development of diagnostic devices, contrast agents, analytical tools, physical therapy applications, and drug delivery vehicles.

1. Diagnostics

Nanotechnology-on-a-chip is one more dimension of lab-on-a-chip technology. Magnetic nanoparticles, bound to a suitable antibody, are used to label specific molecules, structures or microorganisms. Gold nanoparticles tagged with short segments of DNA can be used for detection of genetic sequence in a sample. Multicolor optical coding for biological assays has been achieved by embedding different-sized quantum dots into polymeric microbeads. Nanopore technology for analysis of nucleic acids converts strings of nucleotides directly into electronic signatures.

2. Drug delivery

Nanotechnology has been a boom in medical field by delivering drugs to specific cells using nanoparticles. The overall drug consumption and side-effects can be lowered significantly by depositing the active agent in the morbid region only and in no higher dose than needed. This highly selective approach reduces costs and human suffering. An example can be found in dendrimers and nanoporous materials. Another example is to use block co-polymers, which form micelles for drug encapsulation.[1] They could hold small drug molecules transporting them to the desired location. Another vision is based on small electromechanical systems; NEMS are being investigated for the active release of drugs. Some potentially important applications include cancer treatment with iron nanoparticles or gold shells. A targeted or personalized medicine reduces the drug consumption and treatment expenses resulting in an overall societal benefit by reducing the costs to the public health system. Nanotechnology is also opening up new opportunities in implantable delivery systems, which are often preferable to the use of injectable drugs, because the latter frequently display first-order kinetics (the blood concentration goes up rapidly, but drops exponentially over time). This rapid rise may cause difficulties with toxicity, and drug efficacy can diminish as the drug concentration falls below the targeted range.

3. Tissue engineering

Nanotechnology can help to reproduce or to repair damaged tissue. “Tissue engineering” makes use of artificially stimulated cell proliferation by using suitable nanomaterial-based scaffolds and growth factors. Tissue engineering might replace today’s conventional treatments like organ transplants or artificial implants. Advanced forms of tissue engineering may lead to life extension.

For patients with end-state organ failure, there may not be enough healthy cells for expansion and transplantation into the ECM (extracellular matrix). In this case, pluripotent stem cells are needed. One potential source for these cells is iPS (induced Pluripontent Stem cells); these are ordinary cells from the patient’s own body that are reprogrammed into a pluripotent state, and has the advantage of avoiding rejection (and the potentially life-threatening complications associated with immunosuppressive treatments).

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Another potential source of pluripotent cells is from embryos, but this has two disadvantages: 1). it requires that we solve the problem of cloning, which is technically very difficult (especially preventing abnormalities).

2) It requires the harvesting of embryos. Given that each one of us was once an embryo, this source is claimed by some to be ethically problematic.

4. Chemistry and environment

Chemical catalysis and filtration techniques are two prominent examples where nanotechnology already plays a role. The synthesis provides novel materials with tailored features and chemical properties: for example, nanoparticles with a distinct chemical surrounding (ligands), or specific optical properties. In this sense, chemistry is indeed a basic nanoscience. In a short-term perspective, chemistry will provide novel “nanomaterials” and in the long run, superior processes such as “self-assembly” will enable energy and time preserving strategies. In a sense, all chemical synthesis can be understood in terms of nanotechnology, because of its ability to manufacture certain molecules. Thus, chemistry forms a base for nanotechnology providing tailor-made molecules, polymers, etcetera, as well as clusters and nanoparticles.

5. Catalysis

Chemical catalysis benefits especially from nanoparticles, due to the extremely large surface to volume ratio. The application potential of nanoparticles in catalysis ranges from fuel cell to catalytic converters and photocatalytic devices. Catalysis is also important for the production of chemicals.Platinum nanoparticles are now being considered in the next generation of automotive catalytic converters because the very high surface area of nanoparticles could reduce the amount of platinum required.However, some concerns have been raised due to experiments demonstrating that they will spontaneously combust if methane is mixed with the ambient air. Ongoing research at the Centre National de la Recherche Scientifique (CNRS) in France may resolve their true usefulness for catalytic applications.Nanofiltration may come to be an important application, although future research must be careful to investigate possible toxicity.

2.3.2 Filtration

A strong influence of nanochemistry on waste-water treatment, air purification and energy storage devices is to be expected. Mechanical or chemical methods can be used for effective filtration techniques. One class of filtration techniques is based on the use of membranes with suitable hole sizes, whereby the liquid is pressed through the membrane. Nanoporous membranes are suitable for a mechanical filtration with extremely small pores smaller than 10 nm (“nanofiltration”) and may be composed of nanotubes. Nanofiltration is mainly used for the removal of ions or the separation of different fluids. On a larger scale, the membrane filtration technique is named ultrafiltration, which works down to between 10 and 100 nm. One important field of application for ultrafiltration is medical purposes as can be found in renal dialysis. Magnetic nanoparticles offer an effective and reliable method to remove heavy metal contaminants from waste water by making use of magnetic separation techniques. Using nanoscale particles increases the efficiency to absorb the contaminants and is comparatively inexpensive compared to traditional precipitation and filtration methods.

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Some water-treatment devices incorporating nanotechnology are already on the market, with more in development. Low-cost nanostructured separation membranes methods have been shown to be effective in producing potable water in a recent study.

2.3.3 Energy

The most advanced nanotechnology projects related to energy are: storage, conversion, manufacturing improvements by reducing materials and process rates, energy saving (by better thermal insulation for example), and enhanced renewable energy sources.

1. Reduction of energy consumption

A reduction of energy consumption can be reached by better insulation systems, by the use of more efficient lighting or combustion systems, and by use of lighter and stronger materials in the transportation sector. Currently used light bulbs only convert approximately 5% of the electrical energy into light. Nanotechnological approaches like light-emitting diodes (LEDs) or quantum caged atoms (QCAs) could lead to a strong reduction of energy consumption for illumination.

2. Increasing the efficiency of energy production

Today's best solar cells have layers of several different semiconductors stacked together to absorb light at different energies but they still only manage to use 40 percent of the Sun's energy. Commercially available solar cells have much lower efficiencies (15-20%). Nanotechnology could help increase the efficiency of light conversion by using nanostructures with a continuum of bandgaps.The degree of efficiency of the internal combustion engine is about 30-40% at the moment. Nanotechnology could improve combustion by designing specific catalysts with maximized surface area. In 2005, scientists at the University of Toronto developed a spray-on nanoparticle substance that, when applied to a surface, instantly transforms it into a solar collector.

3. The use of more environmentally friendly energy systems

An example for an environmentally friendly form of energy is the use of fuel cells powered by hydrogen, which is ideally produced by renewable energies. Probably the most prominent nanostructured material in fuel cells is the catalyst consisting of carbon supported noble metal particles with diameters of 1-5 nm. Suitable materials for hydrogen storage contain a large number of small nanosized pores. Therefore many nanostructured materials like nanotubes, zeolites or alanates are under investigation. Nanotechnology can contribute to the further reduction of combustion engine pollutants by nanoporous filters, which can clean the exhaust mechanically, by catalytic converters based on nanoscale noble metal particles or by catalytic coatings on cylinder walls and catalytic nanoparticles as additive for fuels.

2.3.4 Recycling of batteries

Because of the relatively low energy density of batteries the operating time is limited and a replacement or recharging is needed. The huge number of spent batteries and accumulators represent a disposal problem. The use of batteries with higher energy content or the use of

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rechargeable batteries or supercapacitors with higher rate of recharging using nanomaterials could be helpful for the battery disposal problem.

2.3.5 Information and communication

Current high-technology production processes are based on traditional top down strategies, where nanotechnology has already been introduced silently. The critical length scale of integrated circuits is already at the nanoscale (50 nm and below) regarding the gate length of transistors in CPUs or DRAM devices.

2.3.6 Memory Storage

Electronic memory designs in the past have largely relied on the formation of transistors. However, research into crossbar switch based electronics have offered an alternative using reconfigurable interconnections between vertical and horizontal wiring arrays to create ultra-high density memories. Two leaders in this area are Nantero which has developed a carbon nanotube based crossbar memory called Nano-RAM and Hewlett-Packard which has proposed the use of memristor material as a future replacement of Flash memory.

2.3.7 Novel semiconductor devices

An example of such novel devices is based on spintronics.The dependence of the resistance of a material (due to the spin of the electrons) on an external field is called magneto resistance. This effect can be significantly amplified (GMR - Giant Magneto-Resistance) for nano sized objects, for example when two ferromagnetic layers are separated by a nonmagnetic layer, which is several nanometers thick (e.g. Co-Cu-Co). The GMR effect has led to a strong increase in the data storage density of hard disks and made the gigabyte range possible. The so called tunneling magneto resistance (TMR) is very similar to GMR and based on the spin dependent tunneling of electrons through adjacent ferromagnetic layers. Both GMR and TMR effects can be used to create a non-volatile main memory for computers, such as the so called magnetic random access memory or MRAM.

2.3.8 Novel optoelectronic devices

In the modern communication technology traditional analog electrical devices are increasingly replaced by optical or optoelectronic devices due to their enormous bandwidth and capacity, respectively. Two promising examples are photonic crystals and quantum dots. Photonic crystals are materials with a periodic variation in the refractive index with a lattice constant that is half the wavelength of the light used. They offer a selectable band gap for the propagation of a certain wavelength, thus they resemble a semiconductor, but for light or photons instead of electrons. Quantum dots are nano scaled objects, which can be used, among many other things, for the construction of lasers. The advantage of a quantum dot laser over the traditional semiconductor laser is that their emitted wavelength depends on the diameter of the dot. Quantum dot lasers are cheaper and offer a higher beam quality than conventional laser diodes.

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2.3.9 Displays

The production of displays with low energy consumption could be accomplished using carbon nanotubes (CNT). Carbon nanotubes are electrically conductive and due to their small diameter of several nanometers, they can be used as field emitters with extremely high efficiency for field emission displays (FED). The principle of operation resembles that of the cathode ray tube, but on a much smaller length scale.

2.3.10 Quantum computers

Entirely new approaches for computing exploit the laws of quantum mechanics for novel quantum computers, which enable the use of fast quantum algorithms. The Quantum computer has quantum bit memory space termed "Qubit" for several computations at the same time. This facility may improve the performance of the older systems.

2.3.11 Heavy Industry

An inevitable use of nanotechnology will be in heavy industry.

2.3.12 Aerospace

Lighter and stronger materials will be of immense use to aircraft manufacturers, leading to increased performance. Spacecraft will also benefit, where weight is a major factor. Nanotechnology would help to reduce the size of equipment and thereby decrease fuel-consumption required to get it airborne.

Hang gliders may be able to halve their weight while increasing their strength and toughness through the use of nanotech materials. Nanotech is lowering the mass of supercapacitors that will increasingly be used to give power to assistive electrical motors for launching hang gliders off flatland to thermal-chasing altitudes.

2.3.13 Construction

Nanotechnology has the potential to make construction faster, cheaper, safer, and more varied. Automation of nanotechnology construction can allow for the creation of structures from advanced homes to massive skyscrapers much more quickly and at much lower cost.

2.3.14 Refineries

Using nanotech applications, refineries producing materials such as steel and aluminium will be able to remove any impurities in the materials they create.

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2.3.15 Vehicle manufacturers

Much like aerospace, lighter and stronger materials will be useful for creating vehicles that are both faster and safer. Combustion engines will also benefit from parts that are more hard-wearing and more heat-resistant.

2.3.16 Consumer goods

Nanotechnology is already impacting the field of consumer goods, providing products with novel functions ranging from easy-to-clean to scratch-resistant. Modern textiles are wrinkle-resistant and stain-repellent; in the mid-term clothes will become “smart”, through embedded “wearable electronics”. Already in use are different nanoparticle improved products. Especially in the field of cosmetics, such novel products have a promising potential.

2.3.17 Foods

Complex set of engineering and scientific challenges in the food and bioprocessing industry for manufacturing high quality and safe food through efficient and sustainable means can be solved through nanotechnology. Bacteria identification and food quality monitoring using biosensors; intelligent, active, and smart food packaging systems; nanoencapsulation of bioactive food compounds are few examples of emerging applications of nanotechnology for the food industry. Nanotechnology can be applied in the production, processing, safety and packaging of food. A nanocomposite coating process could improve food packaging by placing anti-microbial agents directly on the surface of the coated film. Nanocomposites could increase or decrease gas permeability of different fillers as is needed for different products. They can also improve the mechanical and heat-resistance properties and lower the oxygen transmission rate. Research is being performed to apply nanotechnology to the detection of chemical and biological substances for sensanges in foods.

2.3.18 Nano-foods

New foods are among the nanotechnology-created consumer products coming onto the market at the rate of 3 to 4 per week, according to the Project on Emerging Nanotechnologies (PEN), based on an inventory it has drawn up of 609 known or claimed nano-products.

On PEN's list are three foods -- a brand of canola cooking oil called Canola Active Oil, a tea called Nanotea and a chocolate diet shake called Nanoceuticals Slim Shake Chocolate.

According to company information posted on PEN's Web site, the canola oil, by Shemen Industries of Israel, contains an additive called "nanodrops" designed to carry vitamins, minerals and phytochemicals through the digestive system and urea.

The shake, according to U.S. manufacturer RBC Life Sciences Inc., uses cocoa infused "NanoClusters" to enhance the taste and health benefits of cocoa without the need for extra sugar.

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2.3.19 Household

The most prominent application of nanotechnology in the household is self-cleaning or “easy-to-clean” surfaces on ceramics or glasses. Nanoceramic particles have improved the smoothness and heat resistance of common household equipment such as the flat iron.

2.3.20 Optics

The first sunglasses using protective and anti-reflective ultrathin polymer coatings are on the market. For optics, nanotechnology also offers scratch resistant surface coatings based on nanocomposites. Nano-optics could allow for an increase in precision of pupil repair and other types of laser eye surgery.

2.3.21 Textiles

The use of engineered nanofibers already makes clothes water- and stain-repellent or wrinkle-free. Textiles with a nanotechnological finish can be washed less frequently and at lower temperatures. Nanotechnology has been used to integrate tiny carbon particles membrane and guarantee full-surface protection from electrostatic charges for the wearer. Many other applications have been developed by research institutions such Textiles Nanotechnology Laboratory at Cornell University

2.3.22 Cosmetics

One field of application is in sunscreens. The traditional chemical UV protection approach suffers from its poor long-term stability. A sunscreen based on mineral nanoparticles such as titanium dioxide offer several advantages. Titanium oxide nanoparticles have a comparable UV protection property as the bulk material, but lose the cosmetically undesirable whitening as the particle size is decreased.

2.3.23 Agriculture

Applications of nanotechnology have the potential to change the entire agriculture sector and food industry chain from production to conservation, processing, packaging, transportation, and even waste treatment. NanoScience concepts and Nanotechnology applications have the potential to redesign the production cycle, restructure the processing and conservation processes and redefine the food habits of the people.

Major Challenges related to agriculture like Low productivity in cultivable areas, Large uncultivable areas,Shrinkage of cultivable lands, Wastage of inputs like water, fertilizers, pesticides, Wastage of products and of course Food security for growing numbers can be addressed through various applications of nanotechnology.

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3. NANO RAM

The proprietary NRAM design, invented by Dr.Thomas Rueckes, Nantero’s Chief Technology Officer, Uses carbon nanotubes as active memory element. Nano-RAM is a proprietary computer memory technology from the company Natero. It is a type of nonvolatile random access memory based on the mechanical position of carbon nanotubes deposited on a chip-like substrate. It can replace DRAM, SRAM, flash and ultimately hard disk storage. In other word a universal memory chip suitable for countless existing and new application in the field of electronics.

3.1 Carbon Nano Tube:-

Carbon nanotubes (CNT) are allotropes of carbon with a cylindrical nanostructure. Nanotubes have been constructed with length-to-diameter ratio of up to 132,000,000:1, which is significantly larger than any other material.CNT developed by Sumio Iijima. These cylindrical carbon molecules have novel properties. This property is useful in many applications in nanotechnology, electronics, optics and other fields of science.

Figure: CARBON NANOTUBES

Nanotubes are members of the fullerene structural family. It has ability to conduct electricity as well as copper.it is stronger than steel and as hard as diamond. The wall of a single-walled carbon nanotube is only one carbon atom thick and the tube diameter is approximately 100,000 times smaller than a human hair. Their name is derived from their size, since the diameter of a nanotube is on the order of a few nanometers (approximately 1/50,000th of the width of a human hair), while they can be up to several millimeters in length (as of 2008). Nanotubes are categorized as single-walled nanotubes (SWNTs) and multi-walled nanotubes (MWNTs).

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Advantages Very small in size. Low power consumption

Disadvantage High cost Requirement of high precision Occurrence of impurities

3.2 Technology:-

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 100 nm away.

Fig: STORAGE IN NRAM

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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. However if a larger voltage is applied between the two electrodes, the nanotubes will be pulled towards the upper electrode until they touch it. At this point a small voltage applied between the terminal and upper electrode will allow current to flow (nanotubes are conductors), representing a "1" state. The state can be changed by reversing the polarity of the charge applied to the two electrodes.

What causes this to act as a memory is that the two positions of the nanotubes are both stable. In the off position the mechanical strain on the tubes is low, so they will naturally remain in this position and continue to read "0". When the tubes are pulled into contact with the upper electrode a new force, the tiny Van der Waals force, comes into play and attracts the tubes enough to overcome the mechanical strain. Once in this position the tubes will again happily remain there and continue to read "1". These positions are fairly resistant to outside interference like radiation that can erase or flip memory in a conventional DRAM.

NRAMs are built by depositing masses of nanotubes on a pre-fabricated chip containing rows of bar-shaped electrodes with the slightly taller insulating layers between them. Tubes in the "wrong" location are then removed, and the gold terminals deposited on top. Any number of methods can be used to select a single cell for writing, for instance the second set of electrodes can be run in the opposite direction, forming a grid, or they can be selected by adding voltage to the terminals as well, meaning that only those selected cells have a total voltage high enough to cause the flip.

Currently the method of removing the unwanted nanotubes makes the system impractical. The accuracy and size of the epitaxy machinery (Epitaxy refers to the method of depositing a monocrystalline film on a monocrystalline substrate. The deposited film is denoted as epitaxial film or epitaxial layer. The term epitaxy comes from the Greek roots epi, meaning "above", and taxis, meaning "in ordered manner". It can be translated "to arrange upon".) is considerably "larger" that the cell size otherwise possible. Existing experimental cells have very low densities compared to existing systems; some new method of construction will have to be introduced in order to make the system practical.

2.3 DESIGN and DESCRIPTION:

The design is quite simple. Nanotubes can serve as individually addressable electromechanical switches arrayed across the surface of a microchip, storing hundreds of gigabits of information may be even a terabit. An electric field applied to a nanotubes would cause it to flex downward into depression etched onto the chip’s surface, where it would contact rather another nanotube or touch a metallic electrode.Once bent, the nanotubes can remain that way, including when the power is turned off, allowing for non-volatile operation. Vanderwaals forces, which are weakmolecular forces of attractions, would hold the switch in place until application of fields of different polarity causes the nanotube to return to its straightened position.

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Fig: simple construction of NRAM showing its Various components.

As shown in fig sagging and straightening represent ’1’ and ‘0’ states, respectively, for a random access memory. In its ‘0’state, the nanotube fabric remains suspended above the electrode. When the transistor below the electrode is turned on, the electrode is turned on, the electrode produces an electric field that causes the nanotubes fabric to bend and touch the electrode - a configuration that denotes ‘1’ state. This is the principle of a switching device.

A nanotube memory is faster much smaller while consuming little power. Due to their extraordinary tensile strength, resilience and very high conductivity, nanotubes can be flexed up and down million times without any damage and can make a very good switching contact.

Fig: suspended nanotube switched connection

Nanotubes purchased from bulk suppliers are a form of high -tech carbon soot that contains a residue of about 5 percent iron a containment that must be removed before further processing. It requires a complex filtration process to reduce the amount of iron to the parts per billion levels. The purified carbon nanotubes are deposited as a film on the surface of a silicon wafer without interfering with adjoi ning electrical circuitry from which chips are carved.

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Figure: When reading an OFF state no current flows from the carbon nanotube ribbon to the electrode

Figure: When reading an ON state a current passes from the carbon nanotube to the electrode

Deposition of nanotubes onto the wafer using a gas vapour requires temperatures so high that the circuitry already in place would be ruined. It is therefore done by spraying a special solvent containing nanotube on the top of the silicon disk spinning like a phonograph record. The thin film of nanotubes left after the solvent is evaporated, is subjected to standard semiconductor lithography and etching, which leave the surface groupings of nanotubes with interconnecting wires. Thereafter, chips are cut from the wafer and encapsulated by the standard IC technology

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3. ADVANTAGES:

NRAM has a density, at least in theory, similar to that of DRAM. DRAM consists of a number of capacitors, which are essentially two small metal plates with a thin insulator between them. NRAM is similar, with the terminals and electrodes being roughly the same size as the plates in a DRAM, the nanotubes between them being so much smaller they add nothing to th e overall size. However it seems there is a minimum size at which a DRAM can be built, below which there is simply not enough charge being stored to be able to effectively read it. NRAM appears to be limited only by the current state of art in lithography. This means that NRAM may be able to become much denser than DRAM, meaning that it will also be less expensive, if it becomes possible to control the locations of carbon nanotubes at the scale the Semiconductor Industry can control the placement of devices on SILICON.

Additionally, unlike DRAM, NRAM does not require power to "refresh" it, and will retain its memory even after the power is removed. Additionally the power needed to write to the device is much lower than a DRAM, which has to build up charge on the plates. This means that NRAM will not only compete with DRAM in terms of cost, but will require much less power to run, and as a result also be much faster (write speed is largely determined by the total charge needed). NRAM can theoretically reach sp eeds similar to SRAM, which is faster than DRAM but much less dense, and thus much more expensive.

In comparison with other NVRAM technologies, NRAM has the potential to be even more advantageous. The most common form of NVRAM today is Flash RAM, which combines a bistable transistor circuit known as a flipflop (also the basis of SRAM) with a high-performance insulator wrapped around one of the transistor's bases. After being written to, the insulator traps electrons in the base electrode, locking it into th e "1" state. However, in order to change that bit the insulator has to be "overcharged" to erase any charge already stored in it. This requires high voltage, about 10 volts, much more than a battery can provide. Flash systems thus have to include a "charge pump" that slowly builds up power and then releases it at higher voltage. This process is not only very slow, but degrades the insulators as well. For this reason Flash has a limited lifetime, between 10,000 and 1,000,000 "writes" before the device will n o longer operateeffectively.

NRAM potentially avoids all of these issues. The read and write process are both "low energy" in comparison to Flash (or DRAM for that matter), meaning that NRAM can result in longer battery life in conventional devices. It ma y also be much faster to write than either, meaning it may be used to replace both. A modern cellphone will often include Flash memory for storing phone numbers and such, DRAM for higher speed working memory because flash is too slow, and additionally some SRAM in the CPU because DRAM is too slow for its own use. With NRAM all of these may be replaced, with some NRAM placed on the CPU to act as the CPU cache, and more in other chips replacing both the DRAM and Flash.

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4. Comparison with other proposed systems:

NRAM is one of a variety of new memory systems, many of which claim to be "universal" in the same fashion as NRAM -- replacing everything from Flash to DRAM to SRAM.

The only system currently ready for commercial use is ferroelectric random access memory (FRAM or FeRAM). FeRAM adds a small amount of a ferro–electric material in an otherwise "normal" DRAM cell, the state of the field in the material encoding the bit in a non-destructive format. FeRAM has all of the advantages of NRAM, although the smallest possible cell size is much larger than for NRAM. FeRAM is currently in use in a number of applications where the limited number of writes in Flash is an issue, but due to the massive investment in Flash factories (fabs), it has not yet been able to even replace Flash in the market. Other more speculative memory systems include MRAM and PRAM. MRAM is based on a magnetic effect similar to that utilized in modern hard drives, the memory as a whole consisting of a grid of small magnetic "dots" each holding one bit. Key to MRAM's potential is the way it reads the memory using the magneto -restrictive effect, allowing it to read the memory both non -destructively and with very little power. Unfortunately it appears MRAM is already reaching its fundamental smallest cell size, already much larger than existing Flash devices. PRAM is based on a technology similar to that in a writable CD or DVD, using a phase -change material that changes its magnetic or electrical properties instead of its optical ones. PRAM appears to have a small cell size as well, although current devices are nowhere near small enough to find if there is some practical limit.

5. LIMITATION:-

Over supply of DRAM Is relatively costly NRAM is still in research phase

6. APPLICATION:-

Computer and Laptops (Enabling instant –on performance, with no for boot up) Mobile devices (Faster storage of more data for PDA’s and handhelds) Embedded memory (More powerful microprocessor, microcontroller, other logic device) High speed network server Faster and denser

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5. CONCLUSION:

Though this technology today is limited to laboratories and not economically viable, some new method of construction will have to be introduced in order to make the system practical.one we can see the enabling of instant-on computers, which boot and reboot instantly with un-imaginable memory sizes, as well as high density portable memory - MP3 players with 1000s of songs, PDAs with 10 gigabytes of memory, high-speed network servers and much more.

6. KEYWORDS:

RAM — Random Access MemoryNRAM — Nano Random Access MemoryDRAM — Dynamic Random Access MemorySRAM — Static Random Access Memor yMRAM — Magnetic Random Access MemoryFe RAM — Ferro Electric Random Access MemoryPDA — Personal Digital Assistant

7. REFERENCES:

1. Nanotube RAM could displace silicon memory -J. Eric smith

2. www.wikipedia.com

3. www.nerdshit.com

4. The incredible shrinking Nanotube Memory-E.F.Y magazine.

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