INTRODUCTION:

Nanotechnology is science, engineering, and technology conducted at the nanoscale, which is about 1 to 100 nanometers. Nanoscience and nanotechnology are the study and application of extremely small things and can be used across all the other science fields, such as chemistry, biology, physics, materials science, and engineering. The ideas and concepts behind nanoscience and nanotechnology started with a talk entitled “There’s Plenty of Room at the Bottom” by physicist Richard Feynman at an American Physical Society meeting at the California Institute of Technology (CalTech) on December 29, 1959, long before the term nanotechnology was used. In his talk, Feynman described a process in which scientists would be able to manipulate and control individual atoms and molecules. Over a decade later, in his explorations of ultra precision machining, Professor Norio Taniguchi coined the term nanotechnology. It wasn't until 1981, with the development of the scanning tunneling microscope that could "see" individual atoms, that modern nanotechnology began [7].

Fundamental Concept:

It’s hard to imagine just how small nanotechnology is. One nanometer is a billionth of a meter, or 10-9 of a meter. Here are a few illustrative examples: There are 25,400,000 nanometers in an inch; a sheet of newspaper is about 100,000 nanometers thick on a comparative scale, if a marble were a nanometer, then one meter would be the size of the Earth.

Nanoscience and nanotechnology involve the ability to see and to control individual atoms and molecules. Everything on Earth is made up of atoms—the food we eat, the clothes we wear, the buildings and houses we live in, and our own bodies.But something as small as an atom is impossible to see with the naked eye. In fact, it’s impossible to see with the microscopes typically used in a high school science classes. The microscopes needed to see things at the nanoscale were invented relatively recently—about 25-30 years ago.

Once scientists had the right tools, such as the scanning tunneling microscope (STM) and the atomic force microscope (AFM), the age of nanotechnology was born.

Although modern nanoscience and nanotechnology are quite new, nanoscale materials were used for centuries. Alternate-sized gold and silver particles created colors in the stained glass windows of medieval churches hundreds of years ago. The artists back then just didn’t know that the process they used to create these beautiful works of art actually led to changes in the composition of the materials they were working with.

Today's scientists and engineers are finding a wide variety of ways to deliberately make materials at the nanoscale to take advantage of their enhanced properties such as higher strength, lighter weight, increased control of light spectrum, and greater chemical reactivity than their larger-scale counterparts.

Generation of Nanotechnology:

Mihail (Mike) Roco of the U.S. National Nanotechnology Initiative has described four generations of nanotechnology development. The current era, as Roco depicts it, is that of passive nanostructures, materials designed to perform one task. The second phase, which we are just entering, introduces active nanostructures for multitasking; for example, actuators, drug delivery devices, and sensors. The third generation is expected to begin emerging around 2010-2020 and will feature nanosystems with thousands of interacting components. A few years after that, the first integrated nanosystems, functioning (according to Roco) much like a mammalian cell with hierarchical systems within systems, are expected to be developed.

Some experts may still insist that nanotechnology can refer to measurement or visualization at the scale of 1-100 nanometers, but a consensus seems to be forming around the idea that control and restructuring of matter at the nanoscale is a necessary element. CRN's definition is a bit more precise than that, but as work progresses through the four generations of nanotechnology leading up to molecular nanosystems, which will include molecular manufacturing, we think it will become increasingly obvious that "engineering of functional systems at the molecular scale" is what nanotech is really all about [8].

Figure 1: Generations of nanotechnology development [2].

Nanotechnology is sometimes referred to as a general-purpose technology. That's because in its advanced form it will have significant impact on almost all industries and all areas of society. It will offer better built, longer lasting, cleaner, safer, and smarter products for the home, for communications, for medicine, for transportation, for agriculture, and for industry in general.

Imagine a medical device that travels through the human body to seek out and destroy small clusters of cancerous cells before they can spread. Or a box no larger than a sugar cube that contains the entire contents of the Library of Congress. Or materials much lighter than steel that possess ten times as much strength. Like electricity or computers before it, nanotech will offer greatly improved efficiency in almost every facet of life. But as a general-purpose technology, it will be dual-use, meaning it will have many commercial uses and it also will have many military uses—making far more powerful weapons and tools of surveillance. Thus it represents not only wonderful benefits for humanity, but also grave risks.

Nanotechnology Applications in:

Medicine:

Researchers are developing customized nanoparticles the size of molecules that can deliver drugs directly to diseased cells in your body. When it's perfected, this method should greatly reduce the damage treatment such as chemotherapy does to a patient's healthy cells.

Electronics:

Nanotechnology holds some answers for how we might increase the capabilities of electronics devices while we reduce their weight and power consumption.

Food:

Nanotechnology is having an impact on several aspects of food science, from how food is grown to how it is packaged. Companies are developing nanomaterials that will make a difference not only in the taste of food, but also in food safety, and the health benefits that food delivers.

Fuel Cells:

Nanotechnology is being used to reduce the cost of catalysts used in fuel cells to produce hydrogen ions from fuel such as methanol and to improve the efficiency of membranes used in fuel cells to separate hydrogen ions from other gases such as oxygen.

Solar Cells:

Companies have developed nanotech solar cells that can be manufactured at significantly lower cost than conventional solar cells. Due to which the natural resources like sunlight will be used as energy for carrying respective area of work.

Batteries:

Companies are currently developing batteries using nanomaterials. One such battery will be a good as new after sitting on the shelf for decades. Another battery can be recharged significantly faster than conventional batteries. Durability of battery is much better compared with your decades.

Space:

Nanotechnology may hold the key to making space-flight more practical. Advancements in nanomaterials make lightweight spacecraft and a cable for the space elevator possible. By significantly reducing the amount of rocket fuel required, these advances could lower the cost of reaching orbit and traveling in space.

Fuels:

Nanotechnology can address the shortage of fossil fuels such as diesel and gasoline by making the production of fuels from low grade raw materials economical, increasing the mileage of engines, and making the production of fuels from normal raw materials more efficient.

Better Air Quality:

Nanotechnology can improve the performance of catalysts used to transform vapors escaping from cars or industrial plants into harmless gasses. That's because catalysts made from nanoparticles have a greater surface area to interact with the reacting chemicals than catalysts made from larger particles. The larger surface area allows more chemicals to interact with the catalyst simultaneously, which makes the catalyst more effective.

Cleaner Water:

Nanotechnology is being used to develop solutions to three very different problems in water quality. One challenge is the removal of industrial wastes, such as a cleaning solvent called TCE (Trichloroethylene), from groundwater. Nanoparticles can be used to convert the contaminating chemical through a chemical reaction to make it harmless. Studies have shown that this method can be used successfully to reach contaminates dispersed in underground ponds and at much lower cost than methods which require pumping the water out of the ground for treatment.

Chemical Sensors:

Nanotechnology can enable sensors to detect very small amounts of chemical vapors. Various types of detecting elements, such as carbon nanotubes, zinc oxide nanowires or palladium nanoparticles can be used in nanotechnology-based sensors. Because of the small size of nanotubes, nanowires, or nanoparticles, a few gas molecules are sufficient to change the electrical properties of the sensing elements. This allows the detection of a very low concentration of chemical vapors.

Sporting Goods:

If you're a tennis or golf fan, you'll be glad to hear that even sporting goods has wandered into the nano realm. Current nanotechnology applications in the sports arena include increasing the strength of tennis racquets, filling any imperfections in club shaft materials and reducing the rate at which air leaks from tennis balls.

Fabric:

Making composite fabric with nano-sized particles or fibers allows improvement of fabric properties without a significant increase in weight, thickness, or stiffness as might have been the case with previously-used techniques.

Carbon Nanotubes:

Carbon Nanotubes is a nanomaterial, which is widely developing area in Chemical Sensor nano technology. Some of the Applications being developed for carbon nanotubes include adding antibodies to nanotubes to form bacteria sensors, making a composite with nanotubes that bend when electric voltage is applied bend the wings of morphing aircraft, adding boron or gold to nanotubes to trap oil spills, include smaller transistors, coating nanotubes with silicon to make anodes the can increase the capacity of Li-ion batteries by up to 10 times.

Carbon Nanotube Applications and Uses:

The properties of carbon nanotubes have caused researchers and companies to consider using them in several fields. The following are the survey of carbon nanotube applications introduces many of these uses.

Carbon Nanotubes and Energy:

Researchers at the University of Delaware have demonstarted increased energy density for capacitors whit the use of carbon nanotubes in 3-D structured electrodes. Researchers at North Carolina State University have demonstrated the use of silicon coated carbon nanotubes in anodes for Li-ion batteries. They are predicting that the use of silicon can increase the capacity of Li-ion batteries by up to 10 times. However silicon expands during a batteries discharge cycle, which can damage silicon based anodes. By depositing silicon on nanotubes aligned parallel to each other the researchers hope to prevent damage to the anode when the silicon expands. Researchers at Los Alamos National Laboratory have demonstrated a catalyst made from nitrogen-doped carbon-nanotubes, instead of platinum. The researchers believe this type of catalyst could be used in Lithium-air batteries, which can store up to 10 times as much energy as lithium-ion batteries. Researchers at Rice University have developed electrodes made from carbon nanotubes grown on graphene with very high surface area and very low electrical resistance. The researchers first grow graphene on a metal substrate then grow carbon nanotubes on the graphene sheet. Because the base of each nanotube is bonded, atom to atom, to the graphene sheet the nanotube-graphene structure is essentially one molecule with a huge surface area. Using carbon nanotubes in the cathode layer of a battery that can be produced on almost any surface. The battery can be formed by simply spraying layers of paint containing the components needed for each part of the battery. Carbon nanotubes can perform as a catalyst in a fuel cell, avoiding the use of expensive platinum on which most catalysts are based. Researchers have found that incorporating nitrogen and iron atoms into the carbon lattice of nanotubes results in nanotubes with catalytic properties.

Carbon Nanotubes in Healthcare:

Researchers are improving dental implants by adding nanotubes to the surface of the implant material. They have shown that bone adheres better to titanium dioxide nanotubes than to the surface of standard titanium implants. As well they have demonstrated to the ability to load the nanotubes with anti-inflammatory drugs that can be applied directly to the area around the implant. Reseachers at MIT have developed a sensor using carbon nanotubes embedded in a gel; that can be injected under the skin to monitor the level of nitric oxide in the bloodstream. The level of nitric oxide is important because it indicates inflamation, allowing easy monitoring of imflammatory diseases. In tests with laboratory mice the sensor remained functional for over a year. Researchers have demonstrated artificial muscles composed of yarn woven with carbon nanotubes and filled with wax. Tests have shown that the artificial muscles can lift weights that are 200 times heavier than natural muscles of the same size. Nanotubes bound to an antibody that is produced by chickens have been shown to be useful in lab tests to destroy breast cancer tumors. The antibody-carrying nanotubes are attracted to proteins produced by one type of breast cancer cell. Once attached to these cells, the nanotubes absorb light from an infrared laser, incinerating the nanotubes and the attached tumor. Researchers at the University of Connecticut have developed a sensor that uses nanotubes and gold nanoparticles to detect proteins that indicate the presence of oral cancer. Tests have shown this sensor to be accurate and it provides results in less than an hour.

Carbon Nanotubes and the Environment:

Carbon nanotubes are being developed to clean up oil spills. Researchers have found that adding boron atoms during the growth of carbon nanotubes causes the nanotubes to grow into a sponge like material that can absorb many times its weight in oil. These nanotube sponges are made to be magnetic, which should make retrieval of them easier once they are filled with oil.

Carbon nanotubes can be used as the pores in membranes to run reverse osmosis desalination plants. Water molecules pass through the smoother walls of carbon nanotubes more easily than through other types of nanopores, which require less power. Other researchers are using carbon nanotubes to develop small, inexpensive water purification devices needed in developing countries. Sensors using carbon nanotube detection elements are capable of detecting a range of chemical vapors. These sensors work by reacting to the changes in the resistance of a carbon nanotube in the presence of a chemical vapor.

Researchers at the Technical University at Munchen have demonstrated a method of spraying carbon nanotubes onto flexible plastic surfaces to produce sensors. The researchers believe that this method could produce low cost sensors on surfaces such as the plastic film wrapping food, so that the sensor could detect spoiled food. An inexpensive nanotube-based sensor can detect bacteria in drinking water. Antibodies sensitive to particular bacteria are bound to the nanotubes, which are then deposited onto a paper strip. When the bacteria is present it attaches to the antibodies, changing the spacing between the nanotubes and the resistance of the paper strip containing the nanotubes.

Carbon nanotubes tipped with gold nanoparticles can be used to trap oil drops polluting water. Since the gold end is attracted to water while the carbon end is attracted to oil. Therefore the nanotubes form spheres surrounding oil droplets with the carbon end pointed in, toward the oil, and the gold end pointing out, toward the water.

Carbon Nanotubes Effecting Materials:

Researchers are developing materials, such as a carbon nanotube-based composite developed by NASA that bends when a voltage is applied. Applications include the application of an electrical voltage to change the shape (morph) of aircraft wings and other structures.

Researchers at Rice University have demonstrated a method to reduce the weight of coaxial cable for aerospace applications by using a coating of carbon nanotubes, in place of the conventional wire braid surrounding the core of the cable.

Researchers have found that carbon nanotubes can fill the voids that occur in conventional concrete. These voids allow water to penetrate concrete causing cracks, but including nanotubes in the mix stops the cracks from forming.

Researchers at MIT have developed a method to add carbon nanotubes aligned perpendicular to the carbon fibers, called nanostiching. They believe that having the nanotubes perpendicular to the carbon fibers help hold the fibers together, rather than depending upon epoxy and significanly improve the properties of the composite.

Avalon Aviation incorporated carbon nanotubes in a carbon fiber composite engine cowling on an aerobatic aircraft to increase the strength to weight ratio. The engine cowling is highly stressed components in this aircraft, adding carbon nanotubes to the composite allowed them to reduce the weight without weakening the component.

Carbon Nanotubes and Electronics

Building transistors from carbon nanotubes enables minimum transistor dimensions of a few nanometers and the development of techniques to manufacture integrated circuits built with nanotube transistors.

Researchers at Stanford University have demonstrated a method to make functioning integrated circuits using carbon nanotubes. In order to make the circuit work they developed methods to remove metallic nanotubes, leaving only semiconducting nanotubes, as well as an algorithm to deal with misaligned nanotubes. The demonstration circuit they fabricated in the university labs contains 178 functioning transistors.

Other applications in this area include Carbon nanotubes used to direct electrons to illuminate pixels, resulting in a lightweight, millimeter thick "nanoemissive" display panel. Printable electronic devices using nanotube "ink" in inkjet printers, flexible electronic devices using arrays of nanotubes.

Nanomaterial Applications using Graphene

Applications being developed for graphene include using graphene sheets as electodes in ultracapacitors which will have as much storage capacity as batteries but will be able to recharge in minutes, attaching strands of DNA to graphene to form sensors for rapid disease diagnostics, replacing indium in flat screen TVs and making high strenght composite materials.

Nanomaterial Applications using Nanocomposites

Applications being developed for nanocomposites include a nanotube-polymer nanocomposite to form a scaffold which speeds up replacement of broken bones, making a graphene-epoxy nanocomposite with very high strenght-to-weight ratios, a nanocomposite made from cellulous and nanotubes used to make a flexible battery.

Nanomaterial Applications using Nanofibers

Applications being developed for nanofibers include stimulating the production of cartilage in damaged joints, piezoelectric nanofibers that can be woven into clothing to produce electricty for cell phones or other devices, carbon nanofibers that can improve the preformance flame retandant in funiture.

Nanomaterial Applications using Nanoparticles

Applications being developed for nanoparticles include deliver chemotherapy drugs directly to cancer tumors, resetting the immune system to prevent autoimmune diseases, delivering drugs to damaged regions of arteries to fight cardiovascular disease, create photocatalysts that produce hydrogen from water, reduce the cost of producing fuel cells and solar cells, clean up oil spills, water pollution and air pollution.

Nanomaterial Applications using Nanowires

Applications being developed for carbon nanotubes include using zinc oxide nanowires in a flexible solar cell, silver chloride nanowires to decompose organic molecules in polluted water, using nanowires made from iron and nickel to make dense computer memory - called "race track memory.

Benifits and applications

After more than 20 years of basic nanoscience research and more than a decade of focused R&D under the NNI (National Nanotechnology Initiative), applications of nanotechnology are delivering in both expected and unexpected ways on nanotechnology’s promise to benefit society. Nanotechnology is helping to considerably improve, even revolutionize, many technology and industry sectors like information technology, energy, environmental science, medicine, homeland security, food safety, and transportation, among many others. Described below is a sampling of the rapidly growing list of benefits and applications of nanotechnology.

Most benefits of nanotechnology depend on the fact that it is possible to tailor the essential structures of materials at the nanoscale to achieve specific properties, thus greatly extending the well-used toolkits of materials science. Using nanotechnology, materials can effectively be made to be stronger, lighter, more durable, more reactive, more sieve-like, or better electrical conductors, among many other traits. There already exist over 800 everyday commercial products that rely on nanoscale materials and processes:

Nanoscale additives in polymer composite materials for baseball bats, tennis rackets, motorcycle helmets, automobile bumpers, luggage, and power tool housings can make them simultaneously lightweight, stiff, durable, and resilient.

Nanoscale additives to or surface treatments of fabrics help them resist wrinkling, staining, and bacterial growth, and provide lightweight ballistic energy deflection in personal body armor.

Nanoscale thin films on eyeglasses, computer and camera displays, windows, and other surfaces can make them water-repellent, antireflective, self-cleaning, resistant to ultraviolet or infrared light, antifog, antimicrobial, scratch-resistant, or electrically conductive.

Nanoscale materials in cosmetic products provide greater clarity or coverage; cleansing; absorption; personalization; and antioxidant, anti-microbial, and other health properties in sunscreens, cleansers, complexion treatments, creams and lotions, shampoos, and specialized makeup.

Nano-engineered materials in the food industry include nanocomposites in food containers to minimize carbon dioxide leakage out of carbonated beverages, or reduce oxygen inflow, moisture outflow, or the growth of bacteria in order to keep food fresher and safer, longer. Nanosensors built into plastic packaging can warn against spoiled food. Nanosensors are being developed to detect salmonella, pesticides, and other contaminates on food before packaging and distribution.

Nano-engineered materials in automotive products include high-power rechargeable battery systems; thermoelectric materials for temperature control; lower-rolling-resistance tires; high-efficiency/low-cost sensors and electronics; thin-film smart solar panels; and fuel additives and improved catalytic converters for cleaner exhaust and extended range.

Nano-engineered materials make superior household products such as degreasers and stain removers; environmental sensors, alert systems, air purifiers and filters; antibacterial cleansers; and specialized paints and sealing products.

Nanostructured ceramic coatings exhibit much greater toughness than conventional wear-resistant coatings for machine parts. In 2000, the U.S. Navy qualified such a coating for use on gears of air-conditioning units for its ships, saving $20 million in maintenance costs over 10 years. Such coatings can extend the lifetimes of moving parts in everything from power tools to industrial machinery.

Nanoparticles are used increasingly in catalysis to boost chemical reactions. This reduces the quantity of catalytic materials necessary to produce desired results, saving money and reducing pollutants. Two big applications are in petroleum refining and in automotive catalytic converters.

Nanotechnology is already in use in many computing, communications, and other electronics applications to provide faster, smaller, and more portable systems that can manage and store larger and larger amounts of information. These continuously evolving applications include:

a) Nanoscale transistors that are faster, more powerful, and increasingly energy-efficient; soon your computer’s entire memory may be stored on a single tiny chip.

b) Magnetic random access memory (MRAM) enabled by nanometer‐scale magnetic tunnel junctions that can quickly and effectively save even encrypted data during a system shutdown or crash, enable resume‐play features, and gather vehicle accident data.

c) Displays for many new TVs, laptop computers, cell phones, digital cameras, and other devices incorporate nanostructured polymer films known as organic light-emitting diodes, or OLEDs, as well as Quantum Dots, a type of nanoparticle made of semiconducting material. OLED- and quantum dot-enabled screens offer brighter images in a flat format, as well as wider viewing angles, lighter weight, better picture density, lower power consumption, and longer lifetimes.

d) Other computing and electronic products include Flash memory chips; ultraresponsive hearing aids; antimicrobial/antibacterial coatings on mouse/keyboard/cell phone casings; conductive inks for printed electronics, for RFID/smart cards/smart packaging, more life-like video games and flexible displays for e-book readers.

The difficulty of meeting the world’s energy demand is compounded by the growing need to protect our environment. Many scientists are looking into ways to develop clean, affordable, and renewable energy sources, along with means to reduce energy consumption and lessen toxicity burdens on the environment.

Prototype solar panels incorporating nanotechnology are more efficient than standard designs in converting sunlight to electricity, promising inexpensive solar power in the future. Nanostructured solar cells already are cheaper to manufacture and easier to install, since they can use print-like manufacturing processes and can be made in flexible rolls rather than discrete panels. Newer research suggests that future solar converters might even be “paintable.”

Nanotechnology is improving the efficiency of fuel production from normal and low-grade raw petroleum materials through better catalysis, as well as fuel consumption efficiency in vehicles and power plants through higher-efficiency combustion and decreased friction.

Nano-bioengineering of enzymes is aiming to enable conversion of cellulose into ethanol for fuel, from wood chips, corn stalks (not just the kernels, as today), unfertilized perennial grasses, etc.

Nanotechnology is already being used in numerous new kinds of batteries that are less flammable, quicker-charging, more efficient, lighter weight, and that have a higher power density and hold electrical charge longer. One new lithium-ion battery type uses a common, nontoxic virus in an environmentally benign production process.

Nanostructured materials are being pursued to greatly improve hydrogen membrane and storage materials and the catalysts needed to realize fuel cells for alternative transportation technologies at reduced cost. Researchers are also working to develop a safe, lightweight hydrogen fuel tank.

Various nanoscience-based options are being pursued to convert waste heat in computers, automobiles, homes, power plants, etc., to usable electrical power.

An epoxy containing carbon nanotubes is being used to make windmill blades that are longer, stronger, and lighter-weight than other blades to increase the amount of electricity that windmills can generate.

Researchers are developing wires containing carbon nanotubes to have much lower resistance than the high-tension wires currently used in the electric grid and thus reduce transmission power loss.

To power mobile electronic devices, researchers are developing thin-film solar electric panels that can be fitted onto computer cases and flexible piezoelectric nanowires woven into clothing to generate usable energy on-the-go from light, friction, and/or body heat.

Energy efficiency products are increasing in number and kinds of application. In addition to those noted above, they include more efficient lighting systems for vastly reduced energy consumption for illumination; lighter and stronger vehicle chassis materials for the transportation sector; lower energy consumption in advanced electronics; low-friction nano-engineered lubricants for all kinds of higher-efficiency machine gears, pumps, and fans; light-responsive smart coatings for glass to complement alternative heating/cooling schemes and high-light-intensity, fast-recharging lanterns for emergency crews.

Besides lighter cars and machinery that requires less fuel, and alternative fuel and energy sources, there are many eco-friendly applications for nanotechnology, such as materials that provide clean water from polluted water sources in both large-scale and portable applications, and ones that detect and clean up environmental contaminants.

Nanotechnology could help meet the need for affordable, clean drinking water through rapid, low-cost detection of impurities in and filtration and purification of water. For example, researchers have discovered unexpected magnetic interactions between ultrasmall specks of rust, which can help remove arsenic or carbon tetrachloride from water (see image); they are developing nanostructured filters that can remove virus cells from water; and they are investigating a deionization method using nano-sized fiber electrodes to reduce the cost and energy requirements of removing salts from water.

Nanoparticles will someday be used to clean industrial water pollutants in ground water through chemical reactions that render them harmless, at much lower cost than methods that require pumping the water out of the ground for treatment.

Researchers have developed a nanofabric "paper towel," woven from tiny wires of potassium manganese oxide, which can absorb 20 times its weight in oil for cleanup applications.

Many airplane cabin and other types of air filters are nanotechnology-based filters that allow “mechanical filtration,” in which the fiber material creates nanoscale pores that trap particles larger than the size of the pores. They also may contain charcoal layers that remove odors. Almost 80% of the cars sold in the U.S. include built-in nanotechnology-based filters.

New nanotechnology-enabled sensors and solutions may one day be able to detect, identify, and filter out, and/or neutralize harmful chemical or biological agents in the air and soil with much higher sensitivity than is possible today. Researchers around the world are investigating carbon nanotube “scrubbers,” and membranes to separate carbon dioxide from power plant exhaust. And researchers are investigating particles such as self-assembled monolayers on mesoporous supports (SAMMS™), dendrimers, carbon nanotubes, and metalloporphyrinogens to determine how to apply their unique chemical and physical properties for various kinds of toxic site remediation.

Nanotechnology has the real potential to revolutionize a wide array of medical and biotechnology tools and procedures so that they are more personalized, portable, cheaper, safer, and easier to administer. Below are some examples of important advances in these areas.

Quantum dots are semiconducting nanocrystals that can enhance biological imaging for medical diagnostics. When illuminated with ultraviolet light, they emit a wide spectrum of bright colors that can be used to locate and identify specific kinds of cells and biological activities. These crystals offer optical detection up to 1,000 times better than conventional dyes used in many biological tests, such as MRIs, and render significantly more information.

Nanotechnology has been used in the early diagnosis of atherosclerosis, or the buildup of plaque in arteries. Researchers have developed an imaging technology to measure the amount of an antibody-nanoparticle complex that accumulates specifically in plaque. Clinical scientists are able to monitor the development of plaque as well as its disappearance through clinical treatment.

Gold nanoparticles can be used to detect early-stage Alzheimer’s disease : Molecular imaging for the early detection where sensitive biosensors constructed of nanoscale components (e.g., nanocantilevers, nanowires, and nanochannels) can recognize genetic and molecular events and have reporting capabilities, thereby offering the potential to detect rare molecular signals associated with malignancy. Multifunctional therapeutics where a nanoparticle serves as a platform to facilitate its specific targeting to cancer cells and delivery of a potent treatment, minimizing the risk to normal tissues.

Research enablers such as microfluidic chip-based nanolabs capable of monitoring and manipulating individual cells and nanoscale probes to track the movements of cells and individual molecules as they move about in their environments.

Research is underway to use nanotechnology to spur the growth of nerve cells, e.g., in damaged spinal cord or brain cells. In one method, a nanostuctured gel fills the space between existing cells and encourages new cells to grow. There is early work on this in the optical nerves of hamsters. Another method is exploring use of nanofibers to regenerate damaged spinal nerves in mice. In addition to contributing to building and maintaining lighter, smarter, more efficient, and “greener” vehicles, aircraft, and ships, nanotechnology offers various means to improve the transportation infrastructure:

Nano-engineering of steel, concrete, asphalt, and other cementitious materials, and their recycled forms, offers great promise in terms of improving the performance, resiliency, and longevity of highway and transportation infrastructure components while reducing their cost. New systems may incorporate innovative capabilities into traditional infrastructure materials, such as the ability to generate or transmit energy.

Nanoscale sensors and devices may provide cost-effective continuous structural monitoring of the condition and performance of bridges, tunnels, rails, parking structures, and pavements over time. Nanoscale sensors and devices may also support an enhanced transportation infrastructure that can communicate with vehicle-based systems to help drivers maintain lane position, avoid collisions, adjust travel routes to circumnavigate congestion, and other such activities.

Literature Review

In [1], summarized key design parameters that have been identified to optimize performance. With low material use, high absorption is possible in these structures by tuning geometry dependent resonant absorption characteristics, as predicted by theory and confirmed by experiments. However, the biggest challenge is the high level of synthesis control needed to obtain uniform arrays of nanowires with optimized charge carrier separation and collection properties. Further efforts are needed to optimize the nanowire array solar cells simultaneously in terms of key parameters that are discussed in this review paper. To advance nanowire based solar cells towards possible commercialization the PCE (power conversion efficiency) needs to be increased, for which the tandem architecture is highly interesting.Further cost reduction is also needed, especially when it comes to substrate cost and cost-efficient manufacturing methods for growth. nanowire solar cells are to be implemented on a large scale, proper encapsulation and systems for handling and recycling of material are needed, due to the toxicity and high cost of some of the elements. Rigorous testing will also be needed to evaluate long-term stability and reliability under outdoor operation conditions.

In [2], CNT (Carbon Nano- tube)(dispersion in aqueous solution and the effect of CNTs on the mechanical properties of resulting cement-based materials are reviewed. Sonication and surfactants, as the most commonly used techniques, are introduced. Optimal sonication energy ranges greatly according to research results, which indicates that different properties of CNTs are applied in different area. Electrical resistance change vs. applied stress of CNT/cement mortar composites under cyclic loading (S.S.D.: saturated-surface dry condition; O.D.: oven dry condition). Electrical resistivity of cement paste reinforced with CNTs at a percentage of 0.1 wt.% dried at different temperatures (60 C and 95 C) . Effects of silica fume on electrical resistance of CNT/cement composites are also discussed research work and demonstrated. The shortening effect of sonication on CNTs is mentioned, in that it damages the structure of CNTs. various surfactants are listed and various works in the field of CNT dispersion are compared. The optimal dosage of each surfactant in the dispersion of CNTs from each article is reported. In addition, characterization methods commonly used to identify the dispersion of CNT/CNT solutions are introduced. By forming an electrically conducting network in cement matrix, the electrical conductivity can be greatly enhanced. But the reinforcing effect and sensitivity can be changed by many factors: CNT content, dispersion degree, loading amplitudes, rates and frequencies, agglomerations, current form, intensity and frequencies, moisture content, curing temperature as well as damage on CNT structures. The addition of other materials, like carbon fiber and silica fume, can effectively further improve the effect of CNT on both mechanical and electrical properties.

The exceptional charge conduction properties of carbon nanotubes (CNTs) promise electronic devices of the future with the potential to outperform current technologies based on Si and GaAs. But to date, CNT transistors have significantly underperformed. Now researchers at the University of Wisconsin-Madison have achieved some ofthe best performances ever from field-effecttransistors (FETs) based on arrays of CNTs, The devices, report the researchers, show conductance and current density seven times higher than previous CNT array FETs. The high purity of semiconducting nanotubes also enables the devices to be turned off completely, which is critical for real applications where low-power consumption in the off state is important. The demonstration of a transistor with a dense array of pure, semiconducting CNTs is a significant step forwards, “The transistor performance approaches that of the best reported single CNT transistors and is comparable to Si MOSFETs,” he says. “Although significant technological challenges remain, this work gives us hope that CNT transistors that significantly outperform conventional transistors may be possible”. “The implication for logic applications is that by replacing Si with a CNT channel it should be possible to achieve either a higher performing or lower power device operation,” he says. “The high current density and purity of the CNTs are also desirable for radio frequency amplifiers for wireless communications and for thin film transistor applications such as flat panel displays that require high mobility and transparency.”

In [4], Increasing demands for food require the woe of innovative technologies to ensure the safety of food from farm to plate. Therefore, the applications of nanosensor for food hazards should be further explored. It can be referred to self-contained measurement elements, which are capable of detecting specific chemical compounds in biological samples. Nanomaterials incorporated into various biosensors can play a vital role in assuring food safety in producing a rapid and sensitive detection method due to their excellent properties. Ultimately, the detection procedures are made simpler and easier especially for on-site performance with minimal cost and expertise.

In paper [5], reviews the applications of CNTs (Carbon Nanotubes) and graphene in batteries, with an emphasis on the particular roles (such as conductive, active, flexible and supporting roles) they play in advanced lithium batteries. We will summarize the unique advantages of CNTs and graphene in battery applications, update the most recent progress, and compare the prospects and challenges of CNTs and graphene for future full utilization in energy storage applications.

In the below table we have gone through the some of the paper related to nano materials which are used for storage technology, Transistor technology, Processing technology, Protable devices and some of the hardware and material technologies which make things better in your daily needs. We have discussed concerned to below listed technologies with respect to the concerned paper as list in below table.

Storage Technology: In the area of data storage, it was observed that nanotechnology offered several improvements which included increased storage capacity due to the ability to store data bits on individual atoms, low energy consumption memories, enhanced performance with faster read and write access functions and reliable storage devices (TRN 2003, Rizzo 2009, Limer 2011, Oshita 2014). The results indicated that suitable material that exhibited properties required to achieve the nano storage was carbon nanotubes which are allotropes of carbon (TRN 2003, Oshita 2014). It was further observed that Carbon nanotubes exhibited unusual mechanical properties such as high toughness, unique surface area, high elastic moduli and an excellent semiconductor (Varshney 2014). Other materials that also played a major role included the use of nanowires and chalcogenide material as bits (TRN 2003, Rizzo 2009). It was revealed that different techniques could be employed in the use of a nano-glass that stored data in lenses which could be read by a light source as reported by Limer (2011). This approach was seemed to be very precise allowing optical manipulation of atom-sized objects and ultra high resolution imaging. The results showed that building of nanoelectronic based systems, low power CMOS flip-flop and microelectromechanical systems that can record data bits was possible (Rizzo 2009, TRN 2003). However, low write times and limited write endurance could hamper the progressive use of these applications (Rizzo 2009).

Table 1: Shows the number of paper worked in different areas of nano technology [6].

Rizzo (2009), “Nanoelectronics to improve energy effieciency” – white paper submitted to the nist tip everspin technologies	Storage technology
Trn (2003), Making the future report, data storage: pushing the physical limits, report number 2
Limber (2011), Nano-glass could be the next thing in computer memory storage Oshita (2014), CNT based NRAM shows potential as universal memory, Nikkei BP semiconductor
Simonite (2014), ibm: commercial nanotube transistor are coming soon, mit technology review	Transistor technologies
Francuch (2013), Improving performance of nanotransisotr technology, UIC News center.
Smit (2012) Nano – transistor breakthrough to offer billion times faster computer, the Sydney morning herald
Berger (2010a,) The guture of nanoelectronics – transistors without junctions
Bourzac (2013), the first carbon nanotube computer, MIT technology review	Processing technology
Dillow (2011), the world’s first programmable nanoprocessor takes complex circuitry to the nanoscale
UCLA (2014), Nanoengineering team increases power efficiency for future computer processors, nanowerk news
Coxworth (2011), world’s first self-powered nanodevice with wireless data transmission’ created gizmag	Portable devices
Universidad politecnica de Madrid (2015), flexible nanosensors for wearable devices, nanowerk news
Goodwin (2009), nanotechnology: the future of mobile phones?
Berger (2010b), organic light –emitting transistors out performing OLEDS, Nanowerk.	Hardware and material technology
Oxford university (2014), Nifty little nano-batter is the mighty mite of energy storage, clean technical
Nanowerk news (2014), new battery uses nanotubes to recharge to 70% in just two minutes, nanyang technological university
P2i news (2011), P2i unveils details of commercial – scale liquid repellent nano-coating machjine at mobile world congress
Fountain (2011), written by nokia unveils nano-size waterproof coat for mobiles, cabume
Hallissey (2015), solar nano smartphone case gives your phone perpetual power, psfk
Sung-won (2014), world’s first nano 3D Printer developed by KERI team world’s first nano 3D printer developed by KERI team

Transistor Technology In the area of transistor development, nanotechnology was reported to offer improvements which included: faster microprocessors which were more than five times faster than current silicon technology (Simonite 2014), improved transistor technology which would ensure the realization of quantum computers (Smith 2012), low energy consumption microprocessors (Simonite 2014), reduced cost of fabrication due to the ease of fabricating junction less transistors and development of transistors which are less sensitive to thermal issues (Berger 2010a). The results indicated that Carbon nanotubes played a major role in nano transistors because of their unique properties (Simonite 2014; Francuch 2013). Suitable wires were nanowires which exhibited unique electronic, magnetic, and optoelectronic qualities (Berger, 2010a). The building of what scientists referred to as “the world’s tiniest transistor” was achieved by precisely positioning nanowires and replacing one silicon atom from a group of six with one phosphorous atom (Smith 2012). It was also observed that applications of nanotechnology in the area of transistors included the development of nanotube transistors (Simonite 2014, Francuch 2013) and junctionless transistors that were easy to fabricate at miniature scale as indicated by Berger (2010a). Major challenges or overheads identified from the results were; the need for conducting lots of research and exploration of different methods before commercialization was possible (Simonite 2014) and difficulty in obtaining super thin, ultra pure and defect free silicon crystals for mass production (Berger 2010a).

Information Processing Technology: The results showed potential improvements offered by nanotechnology in information processing technology. These included faster processors, energy efficient processors due to the use of nanomaterials, processors with more computing power, development of processors that have the ability to solve complex tasks at incredible speeds and reduced heating action of processors (Dillow 2011, Bourzac 2013, Nanowerk News 2014). Materials, methods and techniques that played a major role in improved information processing were carbon nanotubes, nanowires and nanocircuits (Dillow 2011, Bourzac 2013). Multiferroic material was reported to be a potential solution to devices heating up due to the flow of electrons in circuits creating wasted energy. The multiferroic material carried power in a cascading wave through the spin of electrons keeping them in the same place but allowing energy to be carried along and increasing power efficiency by 1000 times. (Nanowerk News 2014). The results indicated that super fast carbon nanotube processors could be developed as observed by Bourzac (2013). However, the major challenge or overhead identified was the need for intensive research and exploration (Dillow 2011, Bourzac 2013, Nanowerk News 2014).

Portable Devices: The results revealed several improvements offered by nanotechnology in the area of portable devices. These included the development of light weight devices, energy efficient devices and portable devices with high performance functions (Goodwin 2009, Coxworth 2011, University Politecnica de Madrid 2015). It was observed that the technique employed to develop a self powerednano device that operated battery free was by using a piezoelectric nanogenerator that created electricity from naturally occurring mechanical vibrations and the device was able to transmit wireless signals that could be detected by an ordinary radio at distance over 30 feet (Coxworth 2011). The results indicated other techniques that lowered manufacturing cost and these included dimensional nanohole arrays that were 250 nm drilled into aluminium layer that was 100 nm thick and the manufacture of sensors over compact disc with polycarbonate and transferring the sensors using adhesive scotch tape (Universidad Politecnica de Madrid 2015). It was further observed that various applications included self powered nanodevice capable of transmitting data wirelessly, flexible mobile devices, portable devices with artificial intelligence, organic memory capable of capturing images from the brain, battery free devices, wireless biosensing devices, personal electronics, sensor network and environmental infrastructure monitoring (Goodwin 2009, Coxworth 2011, University Politecnica de Madrid 2015). Major challenges identified were the need to conduct more research and exploration and high cost of development (Goodwin 2009, Coxworth 2011, University Politecnica de Madrid 2015).

Hardware and Material Technology In the area of hardware and material technology, the results indicated that nanotechnology offered several improvements which were cheaper displays, energy efficient displays since nanopixels may not require constant refresh of pixels, super high definition displays, displays with better contrast and colour depth (Oxford University 2014) lower manufacturing cost, durable OLEDs as a result of applying nanocoating (Berger 2010b) batteries which could charge up in minutes, batteries with longer life and more charging cycles, reduction in battery waste (Nanowerk News 2014) waterproof, stain and dirt resistant devices (Fountain 2012) liquid repellent devices and reduction in device corrosion and electrochemical migration (P2i News 2011). Material, methods and techniques played important role in advances in hardware and material technology. The results indicated that carbon nanotubes, nanopixels, organic ink nano particles, nanotube ink, nanopores which form super miniature batteries and photovoltaic cells that can absorb solar energy were possible to apply (Energy Harvesting Journal 2009, Berger 2010b, Oxford University 2014, Hallissey 2015). The results showed that applications of nanotechnology in hardware and material technology were; super large area high resolution displays, super high definition displays, smart glasses, synthetic retina, foldable screens, windshield displays (Oxford University 2014), printable, supercapacitor capable of storing massive amounts of energy (Energy Harvesting 2009), nanoscale battery (Casey 2014), solar nanobattery phone case that automatically tops up phone power giving perpetual energy (Hallissey 2015), water proof and liquid repellent devices, self cleaning devices (Fountain 2012 ), 3D printers capable of printing nano parts, electronic papers, wearable devices and chemical Sensors (Sung-won 2014). Major challenges that were observed included power density; that is, how much power could be stored on a certain amount of space and the need to conduct more research and exploration into these areas (Nanowerk News 2014, Goodwin 2009, Fountain 2012).

CONCLUSION:

Truly revolutionary nanotechnology products, materials and applications, such as nanorobotics, are years in the future. What qualifies as "nanotechnology" today is basic research and development that is happening in laboratories all over the world. "Nanotechnology" products that are on the market today are mostly gradually improved products (using evolutionary nanotechnology) where some form of nanotechnology enabled material (such as carbon nanotubes, nanocomposite structures or nanoparticles of a particular substance) or nanotechnology process (e.g. nanopatterning or quantum dots for medical imaging) is used in the manufacturing process. In their ongoing quest to improve existing products by creating smaller components and better performance materials, all at a lower cost, the number of companies that will manufacture "nanoproducts" will grow very fast and soon make up the majority of all companies across many industries. Evolutionary nanotechnology should therefore be viewed as a process that gradually will affect most companies and industries. Besides moving forward to capture these and many other benefits of nanotechnologies, the NNI is also committed to addressing the potential environmental, health, and safety impacts and various societal, legal, or ethical implications of nanotechnology to avoid or minimize any undesirable or unintended effects of nanotechnology.

REFERENCE:

1. GauteOtnes, Magnus T. Borgström: Towards high efficiency nanowire solar cells, ELSEVIER Nano Today, 2016, pp 1-15. URL: www.elsevier.com/locate/nanotoday.

2. K.M. Liew, M.F. Kai , L.W. Zhang : Carbon nanotube reinforced cementitious composites: An overview, ELSEVIER Composites: Part A, 2016, pp 301-323. URL : www.elsevier.com/locate/compositesa.”

3. Cordelia Sealy: Carbon nanotube transistors align performance with prediction. ELSEVIER Nano Today, 2016. URL : www.elsevier.com/locate/nanotoday.

4. Farah.A., Sukor.R., Fatimah and Jinap.S : Application of nanomaterials in the development of biosensors for food safety and quality control. International Food Research Journal 23(5) pp 1849-1856 (2016).

5. J. Mater. Chem. A: The applications of carbon nanotubes and graphene in advanced rechargeable lithium batteries, Journal of Materials Chemistry, 2016 pp 8932-8951.”

6. Emmanuel G. Ewool, Joseph G. Davis and NajimUssiph: Applications of Nanotechnology to Information Technology: Microscopic Smart Devices (MISD) of the Future, International Journal of Science and Technology, 2016 pp 396-415.

7. http://www.nano.gov/nanotech-101/what/definition.

8. http://www.crnano.org/whatis.htm.

Received on 14.03.2017 Accepted on 16.05.2017

Int. J. Tech. 2017; 7(1): 56-68.

DOI:10.5958/2231-3915.2017.00011.6