An excellent question! A CPU (central
processing unit) is complicated piece of machinery
that is essentially the hardware that allows your
computer to work. While I can't comment too
much on the electrical engineering aspects (e.g.,
circuit design, logic gates), I can give some idea
about the materials.
There are actually many materials that
go into making a CPU, ranging from the substrate
or the interconnects between components; but the
main material is silicon. The basic
building block of any electrical device is a
transistor, and the active material is silicon.
Current computers are based on binary, or
0's and 1's. How this is encoded in the
hardware is through high or low voltages.
transistor is essentially the switch that
toggles between the 'on'/1/high voltage state or
'off'/0/low voltage state. From that you can
build ever more complex devices.
And the material that makes this possible is
You might ask, well, why silicon? The first
reason is because it is a semiconductor.
That means at or around room temperature (which
is around where all your electronics operate),
silicon doesn't conduct electricity. The key
is that although it is not naturally conducting,
we can easily engineer it to be so.
In fact, to make it conductive, we
intentionally put impurities in the
It turns out that silicon isn't actually the
most optimal material we can use for electronic
devices. However, because it is so abundant and
cheap, it is hard to out-compete.
Nevertheless, there are a few driving forces
that are pushing towards other novel materials.
The first is that there are many more specialized
applications for which more expensive and better
materials have a market. The second has to do with
what is known as Moore's law. Named after
Gordon Moore, the co-founder of Intel, Moore's law
is more of a prediction than a law. It states
that the number of transistors in an integrated
circuit doubles about every two years. For the
past 40 some years, that prediction has held more
or less true- every couple of years the components
on an integrated circuit get smaller and smaller.
However, there is a physical limit to which these
components can shrink. We are actually at the
point where we're running into sizes where
quantum mechanical effects are important
(this is on the scale of a few atoms!). Thus,
silicon is only sustainable for a few more
years, if we are to continue improving the
performance of our machines.
We need to find alternate materials with
comparable or better performance. Read more
This is actually a very active field of
research across all kinds of fields- materials
science, physics, and even biology!
Hope this helps!
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