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Molecular Computing

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PCQ Bureau
New Update

Silicon has ruled the microchip world for a long time now.

Right from the days of the 4004, till today’s PIIIs and P4s, it has had a key

role to play in the microchip revolution. But, question is, can it hold on? Can

it continue to provide the backbone to the next-generation processors? Or, would

we see the advent of smaller, faster, and more efficient alternatives?

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That,

only time will tell. But, if recent developments in microchip technology are to

be believed, silicon’s days are numbered and the countdown has begun.

Researchers around the world have built molecular logic gates, which will form

the basis of what they call "Molecular Computers". These logic gates

function just like the logic gates used in today’s computers–the AND, OR,

NOT gates, etc, and the construction of these gates marks a huge step towards

the realization of the ultimate dream.

But, what are these "Molecular Computers"? Unlike

the current silicon chip-based computers, these computers are built on a

crystalline structure. This enables the computers to be so small that you might

not even notice them, even if one was lying right in front of your eyes.

Relative to current standards, these computers would be in the category of today’s

supercomputers, with computational power much, much higher than those of today’s

computers. And all this packed into a size so small, that you might actually

have trouble finding your computer if you kept it somewhere and forgot. To drive

home the point, consider the fact that a computer based on this technology could

pack the power of 100 workstations on the size of a grain of sand.

It’s believed that these computers will need far less power

than the current ones. Such a computer can potentially do approximately a 100

billion (1 followed, by 11 zeros) times better than a current Pentium in terms

of energy required to do a calculation. And this technology is not just

restricted to processors. Storage devices based on this technology may be able

to hold vast amounts of data permanently, doing away with the need to erase

files. Scientists further add that perhaps such computers will also be immune to

computer viruses, crashes, and other glitches. That’s a pleasant relief indeed

in today’s environment, where data is under constant threat from these and

various other factors.

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The development of these logic gates has involved the hard

work and dedication of researchers at the University of California, Los Angeles

(UCLA) and Hewlett-Packard (HP). The first step in this direction was creating a

new compound, called rotaxane, which grows in a crystalline structure. Rotaxane

molecules, sandwiched between metal electrodes, functioned as logic gates.

Scientists working in this field seem to draw their inspiration from the most

powerful processor till today, built no thanks to them–the human brain. The

brain uses very little energy, and yet it has billions of delicate

interconnections. This is why humans and animals can perform complex tasks such

as pattern recognition, which are very difficult for traditional,

semiconductor-based computers.

The information that today’s computers carry is etched on

to them, because of the fact that they are based on silicon chips. And it’s

becoming harder and harder to do this precisely on ever-smaller chips. What’s

more, as the size of transistors decreases from around 90 nanometres (0.00000009

metres) currently, to below 50 nanometres in future, the electrons start to obey

the laws of quantum physics. This will leave these devices useless and also

imposes a limit on how small these devices can be, forcing us to search for

alternatives. On the other hand, molecular computers are devoid of any such

problems, being based on a crystalline structure. A crystal can absorb

information, in the form of an electrical charge, and organize it more

efficiently than traditional silicon-based semiconductor devices. What’s more,

this imposes no restriction on the size of the device, which can, quite

literally be, as small as a grain of dust. Or they could be woven into your

clothing or painted on to the walls–imagine walking around with hundreds of

supercomputers all over your body.

The next step will be structuring the chip. Instead of

etching this structure on to the surface, as is done now with silicon chips, it’ll

be downloaded electrically. All the complexity of the chip could be downloaded

easily, via a wire attached to a bigger computer, which would provide the

structure to our crystalline chip, but for a small problem. The currently

available wires are too big, much bigger than the rotaxane molecules for us to

be able to do this. So scientists are now on to the task of shrinking the wires

until they are the same diameter as the molecules, and then we’ll have the

miniaturized technology. Another alternative is the possible use of carbon

nanotubes, long, thin tubes made of pure carbon. Also known as "Bucky

tubes" they are no thicker than most molecules.

But what has excited people all around the world is the wide

variety of uses such computers could be put to, doing tasks modern day computers

can’t even come close to doing. Such chips could, for example, have

unbelievable applications in the field of medicine. Such a microscopic sensor

could come along side a particular breed of bacteria and, quite possibly,

identify the bacteria or disease from inside the body and could feasibly be used

to administer medications internally. Also, an auxiliary, biologically-based

processor may quite possibly be capable of recognizing hazardous materials or

perform really complex tasks, such as identifying spending patterns on credit

applications. Ultimately we’ll have computers approaching and, quite possibly,

even surpassing the power of the human brain. Vast improvements in disease

prevention, diagnosis and treatment will increase life expectancy. These

non-power hungry computers will leave us cheaper and more abundant energy.

But, wait don’t cancel the order of that Athlon, not just

yet. A prototype of a molecular computer won’t be ready for at least another

five years, which you could buy ten years from now.

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