Page 22 - Concise Encyclopedia of Robotics

Alternative Computer Technology
by light transmittivity instead. Certain materials change their optical
properties very quickly, and can hold a given state for a long time.
Atomic data
As integrated circuit (IC) technology has advanced, more and more digital
logic gates have been packed into less and less physical space. Also, with
refinements in magnetic media, the capacity of hard disks and diskettes
has been increasing.
According to conventional science, the smallest possible data storage
unit is a single atom or subatomic particle. Consider a magnetic diskette.
Logic 1 might be represented by an atom “right side up,” with its magnetic
north pole facing upward and its magnetic south pole facing downward.
Then logic 0 would be represented by the same atom “upside down,” with
the magnetic poles inverted.
Another possibility is single-electron memory (SEM). An example of a
SEM is a substance in which the presence of an excess electron in an atom
represents logic 1, and the electrically neutral state of the atom represents
logic 0.
Some scientists think that computer chips might someday be grown
in a laboratory, in a manner similar to the way experimental cultures of
bacteria and viruses are grown. A name has even been coined for such a
device: biochip.
Nanotechnology
As ICs get more circuitry packed into small packages, computer power
increases.But it also becomes possible to make tinier and tinier computers.
With molecular computer technology—the construction of ICs molecule
by molecule rather than by etching material away from a chip—it might
become possible to build computers so small that they can circulate inside
the human body.
Imagine antibody robots, controlled by a central computer, that are as
small as bacteria. Suppose the central computer is programmed to destroy
certain disease-causing organisms. Such a machine would be something
like an artificial white blood cell. Nanotechnology is the field of research
devoted to the development and programming of microscopic machines.
The prefix nano- means one billionth (10 9 or 0.000000001). It also
means “extremely small.”
Computerized nanorobots might assemble larger computers, saving
humans much of the work now associated with manufacturing the
machines. Nanotechnology has already made it possible for you to wear
a computer on your wrist, or even have a computer embedded some-
where in your body.
See also BIOCHIP, INTEGRATED CIRCUIT, NANOCHIP, and NEURAL NETWORK.

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