NANOTECHNOLOGY And Its applications

By, A.L.Hanisha K.V.Padmaja G.Rajeswari College: Raghu Institute of Technology Branch: Computer Science Engineering

What is nanotechnology?Nanotechnology 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. It is named in the year 1974 by Norio Taniguchi.

One nanometer (nm) is one billionth, or 109, of a meter. By comparison, typical carbon-carbon bond lengths, or the spacing between these atoms in a molecule, are in the range 0.120.15 nm, and a DNA double-helix has a diameter around 2nm. On the other hand, the smallest cellular life-forms, the bacteria of the genus Mycoplasma, are around 200nm in length.

Types of Nanotechnology:-There are many different types of Nanotechnology available. In general they can be classified into the following categories: 1) Carbon nanotube2) Optical (or particle-wave based)3) Crystalline4) DNA5) Quantum Each of these categories has a significant impact in the study of Nanotechnology. You see, Nanotechnology is not just technology. It is the study of atoms, and the world as we know it. It is the ability to look deep into what and how basic elements are created and how they can be manipulated to benefit mankind. For now, lets take a look at some of the basics from each of these categories.

Carbon Nanotubes. An oversimplified analogy might be that of a vacuum tube; however the tube is made of carbon molecules instead of glass. The carbon nanotube can contain other substances, any substance that is desired which doesnt interact with carbon molecules. Since carbon is the most non-interactive molecule, it becomes the logical choice to be a container. Once the nanotube is filled with its payload, it can be sealed in a number of different waysbut in general, a breakable bond is setup between one part of the tube, and another (between multiple carbon elements). Of course the tubes, can be strung together to create wire-like properties. The surprising thing is they are not limited to moving just electricity! They can also contain any number of other substances and move those along the tube as well. The carbon nanotubes form the containment structure and dont conduct electricity. But because the nanotubes are hexagonal shape, and have holes, the contained chemicals within can be shifted into different materials through the application of electricity.

A nanotube consisting of carbon molecules

Optical or Particle Wave Based Nanotechnology This is a much different method of computation. It involves the notions that particles can act as both waves and atoms at the same time. The best or simplest explanation here is the notion of light, or light waves if you will. Think back to high school physics and chemistry. (Remember the photon? Its both a particle and a wave at the same time. Nanotechnology is exploring the use of particle wave exchanges for multiple computation abilities; in other words, exchanging electrons (without wires) between computational devices by creating standing waves from one device, passing the waves through walls, through space, and around the world. This amounts to instant communication, no wires. Theyre also investigating wireless power for the same reasons. The use of optical Nanotechnology in bioinformatics to stain cells and watch DNA computation is incredible compared to the old dying the cell methods. There are tremendous advances for light-emitting nano compounds that help us dive deeper and allow us to better understand our tiny world.

Crystals and Nanotechnology

Nanocrystals are structures which basically are attached in a lattice or crystalline shape (like ice for instance, thats a crystalline form of water when it freezes). These structures (because of their lattice shape) are extremely strong. For example, a 3-inch-thick slab of ice can be much stronger than a 3-inch-thick piece of red-wood. Nanocrystals are not yet used as computational devices, but in the future, this may change. We may actually come to have something like a crystalline computing device that reacts to sound waves and changes colors without any visible power-source. "Metal nanocrystals might be incorporated into car bumpers, making the parts stronger, or into aluminum, making it more wear resistant. Metal nanocrystals might be used to produce bearings that last longer than their conventional counterparts, new types of sensors and components for computers and electronic hardware. Nanocrystals of various metals have been shown to be 100 percent, 200 percent and even as much as 300 percent harder than the same materials in bulk form. Because wear resistance often is dictated by the hardness of a metal, parts made from nanocrystals might last significantly longer than conventional parts." Another use for nanocrystals is to house anti-bacterial material without drug interaction and without chemical bonding at the site. For instance, a company produces Nanotechnology crystalline structures with silver that helps to eliminate bacterial infection. The nanocrystalline coating of silver rapidly kills a broad spectrum of bacteria in as little as 30 minutes. DNA Computing This is of particular interest to me. It holds incredible promise, yet at the same timeincredible risks. DNA Nanotechnology or computing is the ability of man to understand, map, manipulate, replicate and alter strands of DNA within molecules. Of course, each cell is comprised of many DNA strands. The cell with RNA and enzymes can perform on its own like a mini-computer. As I wrote in one of my recent Nanotechnology articles (DNA Computing), it has been done already, by DARPA in 1999. They managed to search terabytes of information in fewer than 10 seconds in a DNA solution within a beaker. I would suggest reading DNA computing devices.

Quantum Nanotechnology Quantum Nanotechnology is the sum of all things based on quantum mechanics, in other wordsall of the above types of Nanotechnology rolled together. It is mankinds ability to control the atom and the atomic elements, even creating our own atomic elements that are not found in nature.

ApplicationsNanotechnology is used in many areas of engineering as well as other side of engineering. Now a day, as it is a hot technology in this world, some of the major areas in which it is used are:1) Environment2) Energy3) Medicine4) Security5) Space

EnvironmentThere is strong evidence that most of the warming over the last 50 years is caused by the buildup of greenhouse gases mostly carbon dioxide, methane, and nitrous oxide. Why is this happening? Most scientists believe that the increased use of fossil fuels to run cars and trucks, heat/cool homes, operate industry businesses, and power factories is the primary reason. Nanotechnology is offering a range of new opportunities. For example, nanotech researchers are working on the development of a solar panel/fuel cell combination. The idea behind the technology is that when the solar panel is producing energy, the fuel cell is running in reverse to collect excess energy, convert it to hydrogen, and store it. When the sun goes down and the solar panel is no longer producing energy, the fuel cell will run forward and produce energy from the hydrogen it has stored.Solar CellsSolar Panels These are all used using nano cells.EnergyThe majority of the worlds energy comes from fossil fuels primarily coal, oil, and natural gas. Here is a limited supply of fossil fuels and they are nonrenewable. Today, we are using fossil fuels faster than we are finding them. In fact, the Oil Depletion Analysis Center (ODAC) predicts that in the near future the demand for fossil fuels will far exceed the Earths supply. Researchers are exploring ways in which nanotechnology could help us accomplish the following two goals:

(1) Access and use fossil fuels much more efficiently so that we can get more energy out of current reserves.

(2) Develop new ways to generate energy.

One example of processes being developed to use fossil fuels more efficiently is the current research to design zeolite catalysts at the nanoscale. Researchers at the University of Toronto are using nanotechnology to develop solar panels capable of harnessing not only the visible light from the sun, but the infrared spectrum as well, thus doubling the energy output. Whats more, these new solar cells could be sprayed on surfaces like paint, making them highly portable. Researchers at Rice University want to take solar energy research even further. They hope to someday build a solar power station in space capable of catching the solar energy that bypasses the Earth every day and providing about nine times the efficiency of solar cells on Earth.

MedicineInvestigators are looking to nanotechnology to develop highly sensitive disease detectors, drug delivery systems that only target the disease and not the surrounding healthy tissue, and nanoscale building blocks that help repair skin, cartilage, and/or bone. Researchers are investigating nanoparticles as drug carriers. These nanoscale drug carriers could be coated with nano-sensors, which could recognize diseased tissues and attach to them, releasing a drug exactly where needed. Nanoparticles could also be used to enter damaged cells and release enzymes that tell the cells to auto-destruct, or they could release enzymes to try to repair the cell and return it to normal functioning. Researchers around the world are working to unlock the potential of nanotechnology as it relates to the field of medicine.

SecurityEmerging nanotechnologies are expected to play a critical role in helping to maintain national security. They include new and powerful bio-detection schemes that can analyze a potential bioterrorism threat at the point-of-care, materials that can detoxify an area or human exposed to a set of toxins, and novel ways of encoding structures that can be used to secure computer systems.As the battlefield moves from military targets to civilian, biological and chemical weaponry may play an increasingly dominant role. Protection from these threats depends on the ability to detect, respond, and control biological and chemical threats before they can harm the body.

Nanosensors' ability to detect at the molecular or even atomic level is critical. While in the realm of medicine, biosensors can detect the onset of disease; in the area of national security, they could be used to detect radioactive materials or toxins like anthrax. Researchers working in the areas of nanoelectronics and nanocomputing hope to integrate transistor-like nanoscale devices into system architecture, to provide substantial advantages over current technologies. They are also working on the creation of powerful grid protocols that could make the world wide web obsolete, and something called quantum cryptography that could provide the type of electronic security systems that are impossible to crack.The goal of the ISN is to use nanotechnology to create uniforms and gear that will protect and heal the foot soldiers of the future. Although not the only research effort in this area, the ISN is the largest.

SpaceNanotechnology may hold the key to making spaceflight more practical. Advancements in nanomaterials make lightweight solar sails 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. In addition, new materials combined with nanosensors and nanorobots could improve the performance of spaceships, spacesuits, and the equipment used to explore planets and moons, making nanotechnology an important part of the final frontier.Researchers are looking into the following applications of nanotechnology in spaceflight:1) Using carbon nanotubes to make the cable needed for the Space-elevator a system which could significantly reduce the cost of sending material into orbit.2) Including layers of bio-nano robots in spacesuits. The outer layer of bio-nano robots would respond to damages to the spacesuit, for example to seal up punctures. An inner layer of bio-nano robots could respond if the astronaut was in trouble, for example by providing drugs in a medical emergency.3) Deploying a network of nanosensors to search large areas of planets such as Mars for traces of water or other chemicals.4) Employing materials made from carbon nanotubes to reduce the weight of spaceships while retaining or even increasing the structural strength.5) Producing thrusters for Space-craft that use MEMS devices to accelerate nanoparticles. This should reduce the weight and complexity of thruster systems used for interplanetary missions. One cost-saving feature of these type of thrusters is their ability to draw on more or less of the MEMS devices depending upon the size and thrust requirement of the spacecraft, rather than designing and building different engines for different size spacecraft.6) Using carbon nanotubes to build lightweight solar sails that use the pressure of light from the sun reflecting from the sun reflecting on the mirror like solar cell to propel a space-craft. This solves the problem of having to lift enough fuel into orbit to power spacecraft during interplanetary missions.7) Working with nanosensors to monitor the levels of trace chemicals in spacecraft to monitor the performance of life support systems.

Why is nanotechnology important?Nanotechnology is creating a wealth of new materials and manufacturing possibilities, which in turn will profoundly impact our economy, our environment, and our society. Using nanotechnology, researchers and manufacturers can fabricate materials literally molecule-by-molecule. They can harness previously inaccessible properties of matter and custom design ultra-precise new structures, devices, and systems with new, unique, and often remarkable propertiessuch as materials with vastly increased strength, vastly decreased weight, vastly greater electrical connectivity, or the ability to change shape or color on demand.

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