English for Specific Purposes

26 Electronic Engineering

OPTICS

An area of electronics in which nanotechnology can make a significant difference is optics; specifically displays and lighting. It is true that displays have been becoming lighter and of a much higher standard in recent years, but they are still not very portable, and take up a lot of space. Imagine if a crystal-clear display existed that could be rolled up or folded away when not in use? Or a light bulb that wasted no energy?

New Lighting

Incandescent light bulbs are extremely inefficient converting only about 10% of the electricity they use into light, the rest is lost as heat. Although energy saving bulbs are more efficient, they lose a significant amount of energy as well. Light emitting diodes (LEDs) lose very little energy as heat and also last up to 20 times longer than conventional light bulbs. With advances in their nanocrystalline structure, they are now emitting more light per watt of power consumed than incandescent bulbs and about the same as fluorescent bulbs. Using different semiconductor materials, different colors of LED are possible.

New Displays

Nanotechnology brings about a new era of displays in a number of ways.

Organic Light Emitting Diodes (or OLEDs) are cheaper and easier to manufacture than LEDs. These consist of thin layers of electrically conducting organic molecules which are approximately 100 nm thick. The convenience of these is that they can be applied to different materials using a process similar to ink-jet printing. The downside is that OLEDs have a much shorter life-span and are also much less efficient than LEDs. The main applications of OLEDs are in small video screens such as mobile phones.

Carbon nanotubes are now being prepared for use in displays because of their amazing chemical, physical and mechanical properties. They are up to 100 times stronger than steel, yet only 1/6 of the weight. Carbon nanotubes can even be flexible; in addition, they conduct electricity better than copper.

This method may be looking quite far into the future, but MIT researchers have created a quantum dot OLED (QD-OLED). Quantum dots generate their own light - unlike traditional LCDs which are lit from behind - and the dots can be manipulated to emit absolutely any color imaginable, with no range limit as seen with traditional devices.

COMPUTERS

Computer industry is set to be advanced a further giant step with the application of nanotechnology. Nanotechnology gives scope to develop new ideas and methods of running super-fast processors, storing data, and many other computational advances. It also allows for new applications which require more processing power, either to be smaller or less energy intensive.

Faster Processors

As a result of the current technology limitations, manufacturers are turning to nanotechnology to produce the next generation of processors and computer components. Chipmakers are already working at the nanoscale. Many companies are now producing processor chipsets of around 60nm, with Intel being close to market with their 65nm products. Such chipsets feature greater performance as a result of a 10-15% improved drive current through the application of nanotechnology. They also suffer from less 'leakage', therefore offering large power savings. IBM researchers have developed transistors from carbon nanotubes. These have shown vast improvements on the more conventional silicon transistors: in the lab, they delivered more than double the amount of electrical current compared to the top-performing transistors currently on the market.

New Memory Types

Nanotechnology also offers the solution for larger storage in smaller spaces. However, most are still in development, and the smaller the components get, the more expensive they are to initially produce. One such new data-storage device is the use of nanosized ‘dots’ of nickel which is hoped to store terabytes of data. Each "nanodot" consists of a discrete ball of several hundred nickel atoms and can have one of two magnetic states. This allows them to hold a single bit of information - a '1' or a '0' - as is the computing convention. In current hard drives, bits (of information) must be placed far enough apart so as not to interfere with each other. Nanodots operating as complete units which are not structurally linked are packed closer together. They arrange themselves at such a density that allows up to 5 terabytes of data to be stored in a space the size of a postage stamp. Work still has to be carried out to allow these nanodots to operate and interact with other computing devices, such as silicon chips, but the technology is definitely showing promise.