Nanotech Shaping up the Future

Scientists are working on materials that are much smaller than a single strand of hair to shape the future. There are over 800 manufacturer-identified nanotech products that are publicly available

Monday, June 01, 2009

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In 1959, physicist and future Nobel prize winner Richard Feynman gave a lecture to the American Physical Society called "There's Plenty of Room at the Bottom." The focus of his speech was about the field of miniaturization and how he believed man would create increasingly smaller, powerful devices. We now know what he meant.

Nanotechnology has been the buzzword for quite some while now. But to understand this unusual world of Nanotechnology, it would be better to understand the nanometer first. A centimeter is one-hundredth of a meter, a millimeter is one-thousandth of a meter, and a micrometer is one-millionth of a meter, but all of these are still huge compared to the nanoscale. In fact they are massive. A nanometer (nm) is one-billionth of a meter, that is smaller than the wavelength of visible light and a hundred-thousandth the width of a human hair. Also known as 'Nanotech', this new age physics deals with the study of matter at an atomic or molecular scale and is expected to drive most of the future manufacturing technologies. In simpler words, Nanotechnology is helping us build machines at a subatomic level. Advantages being, it can and will make most products lighter, stronger, cleaner, less expensive and more precise.

As of August 2008, the Project on Emerging Nanotechnologies estimates that over 800 manufacturer-identified nanotech products are publicly available, with new ones hitting the market at a pace of 3-4 per week. Even as of now, most of these applications are limited to the use of "first generation" passive nanomaterials which includes titanium dioxide in sunscreen, cosmetics and some food products; Carbon allotropes used to produce gecko tape; silver in food packaging, clothing, disinfectants and household appliances; zinc oxide in sunscreens and cosmetics, surface coatings, paints and outdoor furniture varnishes; and cerium oxide as a fuel catalyst. Let's have a look at some of these amazing technologies which are shaping the future.

Nanowires and Nanotubes
Currently, scientists are finding two nano-size structures of great interest: nanowires and carbon nanotubes. Nanowires are wires with an extremely small diameter, sometimes as small as 1 nanometer. Scientists hope to use them to build tiny transistors for computer chips and other electronic devices. In the last couple of years, carbon nanotubes have overshadowed nanowires. A carbon nanotube is a nano-size cylinder of carbon atoms. Imagine a sheet of carbon atoms, which would look like a sheet of hexagons. When you roll this sheet into a tube, what you'd have is a carbon nanotube. Properties of carbon nanotubes depend on how you roll the sheet.

In other words, even though all carbon nanotubes are made of carbon, they can be very different from one another based on how you align the individual atoms. With the right arrangement of these atoms, one can create a carbon nanotube that's hundreds of times stronger than steel, but at the same time is six times lighter. Now that sounds like a dream come true for engineers looking for materials for building cars and planes doesn't it. Carbon nanotubes are also likely to be used in IT. These tubes can be either conducting or semiconducting and have the potential for memory and storage as well.

These four diagrams explain how tiny is a nanometer.

Other options for data storage include the use of SPMs (scanning probe microscopes) as a tool for information transfer. This is exemplified by the IBM 'millipede' system, which employs an array of AFMs (atomic force microscopes) tips to make indentations in a polymer and then read them, much in the same way as a laser reads a CD but at a considerably smaller size scale and with a much higher density of information.

An interesting way in which carbon nanotubes are being used is in the development of a high density, nonvolatile random access memory chip that could replace dynamic RAM, flash memory and even hard drives. Nantero, a nanotechnology company, has built using nanotubes a chip called NRAM (for nanotube-based/nonvolatile RAM) that is faster than DRAM, as portable as flash memory, and able to provide permanent storage because the wafer uses nonvolatile storage as its basis.

The technology has the potential to enable instant-on computers that boot and reboot without delays and eliminate the need for internal disk drives on computers.

Nanotechnology also has something in store for display devices, such as the replacement of cathode ray tube (CRT) technology by electron-producing carbon nanotubes. The timing of when these applications are offered in finished products is uncertain, but nanotechnology is already contributing to increased data storage capacity and processing speeds.

Smart materials and nanosensors
Smart materials is one of the proposed applications of molecular nanotechnology. The term refers to any sort of material designed and engineered at the nanometer scale to perform a specific task, and encompasses a wide variety of possible commercial applications. One example of such materials would be materials designed to respond differently to various molecules; such a capability could lead, for example, to artificial drugs which would recognize and render inert specific viruses. In the same way as self-sealing tires or human skin, another is the idea of self-healing structures, which would repair small tears in a surface naturally Similarly, A nanosensor would resemble a smart material, involving a small component within a larger machine that would react to its environment and change in some fundamental, intentional way.

As a very simple example: a photosensor could passively measure the incident light and discharge its absorbed energy as electricity when the light passes above or below a specified threshold, sending a signal to a larger machine. Such a sensor would cost less and use less power than a conventional sensor, and yet function usefully in all the same applications - for example, turning on parking lot lights when it gets dark.

Environment friendly Energy systems
Fuel cells being powered by hydrogen are a great example of an environmentally friendly form of energy. The catalyst consisting of carbon supported noble metal particles with diameters of 1-5 nm is the most prominent nanostructured material in fuel cells. 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. Advances in these can help changing the way energy is being produced in the world to run automobiles and factories.

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