A new type of electromechanical computer built from components
a millionth the thickness of the human hair could soon be
gearing up to do high speed computation, according to
researchers writing in the New Journal of Physics today.
Long before silicon chips were to be found at the heart of the
computer, even before transistors and thermionic valves, there was the
concept of the mechanical computer, a machine to be built from
levers, ratchets and cogs, complete with brass fittings and a Victorian
flourish. The mechanical computer was never to be, at least
not while microelectronics devices could carry out
computations incredibly quickly by shuffling electrons.
Now, however, the emergence of nanotechnology brings with it
the opportunity to manipulate materials close to the individual
molecular level. So, could a nano-electromechanical computer
Robert Blick and colleagues in the department of Electrical
& Computer Engineering, at the University of Wisconsin-Madison,
USA, believe so.
team propose a fully mechanical computer based
on electromechanical units, a billionth of a metre in size.
These units might be based on tiny chunks of diamond or
another superhard material that changes shape when an electric
current is applied, so-called piezoelectric materials.
The units could be integrated into current silicon chip
manufacturing processes and would operate essentially by
pushing and pulling on each other, actuating connected
elements to create switches, logic gates, and memory units. They would
be the mechanical equivalent of the microscopic transistors on
a silicon chip.
The fact that these nano-electromechanical units will be a
thousandth the size of a transistor means that many, many more
could be packed into the same space. The much smaller
separation of logic gates also means that such a computer
might eventually be made much faster than one based on
the conventional silicon chip.
The researchers also point out that electromechanical elements
will have several other advantages over silicon chip
technology. They will use less power, for instance, and they
will generate far less waste heat and so be able to operate at
much higher temperatures without expensive and noisy cooling
systems. They could also withstand voltage surges that can burn
out a silicon chip. These advantages mean that the technology
could be used in more extreme environments than today's
computers, such as very hot conditions (exceeding 200 degrees
Celsius), within high voltage electrical installations, or in
the harsh environment of space.
This is a novel, breakthrough technology rather than an
incremental change, which could lead to a new class of
computer that is far more energy efficient than current
machines, requires no cooling and can work in extreme environments.
The technology exists to make the nano-electromechanical elements;
the next step is to integrate them into a computational device
and build a computer.