X-Message-Number: 1122
Date: Mon, 10 Aug 1992 16:35 MST
Subject: for cryonet and sci.cryonics

The following article appeared in the latest issue of _OE Reports_
(no. 104, August 1992), published be SPIE, the International
Society for Optical Engineering.

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      The Institute for Microstructure Technology at the Nuclear
Research Center in Karlsruhe (Germany) has developed a process to
allow the production of 3-D micromechanical components like
gearwheels, turbines, and filters with a high degree of precision
and, above all, so that they can be reproduced.
      In the LIGA process, the researchers from Karlsruhe combined
the methods of lithography and electroplating with plastic forming
techniques. In the lithography stage, the extremely minute
"blueprint" of the planned component is projected onto a layer of
radio-sensitive plastic, using penetrative and extremely parallel
x-rays from a synchrotron. The exposed areas are then dissolved out
with a developing fluid. In the second stage, the resulting relief
is filled out with metal that is applied electrochemically. It is
then possible to produce the desired structures themselves or the
corresponding metal forms, which can be used for mass production
involving plastic molding.
      As the synchrotron radiation is very concentrated, outlining
images very sharply, it is capable of providing great structural
depth. Consequently, it has allowed, for the first time, the
production  of structures having extremely small horizontal
dimensions of a few micrometers, but nevertheless, having a height
of several hundred micrometers. In this manner, the institute at
Karlsruhe has been able to produce microstructures from metals,
metal alloys, plastics, and ceramics.
      By combining the steps of the LIGA process, it is also
possible to produce components for very tiny machines, for example,
an electromotor consisting of a rotor with a radius of 200
micrometers, rotating on an axis having a radius of 115
micrometers. With a height of roughly 100 micrometers, which is
considerable, the rotor is surrounded by six stators, where the
rotating electromagnetic field, which makes the rotor turn, is
generated at approximately 100 volts. The speed of the motor can be
varied from stepping operation up to 3400 rotations per minute. END

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      This process for mass production of complicated, three
dimensional structures of micrometer size is important to cryonics
because inexpensive micromachinery is necessary for the development
of the "nanotechnology workstation", an STM-based nanofabrication
platform useful in the subsequent development of nanotechnological
devices. Micrometer scale machine parts have vibrational
frequencies at leat 1000 times higher than macroscopic parts,
allowing construction of scanning probe microscopes and related
devices that can operate at megahertz data rates. Present
microscopes of this type operate at tens of kilohertz or lower,
making "real time" observation and manipulation of atoms and
molecules very difficult. "Silicon foundries" presently will
produce custom designed ICs when given the customer's circuit
designs; this new lithographic micromachine production technique
promises to extend this capability to a wide variety of mechanical
      With the development of this process, I think that a properly
organized and funded R&D lab could sucessfully develop a commercial
nanotechnology workstation.
      Micromachinery also has important potential applications in
"conventional" medicine; scientists in Japan and elsewhere are
working on "microrobots" designed to circulate in the bloodstream
and relay temperature, pressure, pH and other conditions back to an
external computer, in the manner of the miniaturized submarine in
the movie "Fantastic Voyage". This has obvious uses in the
suspension process. ----Mark A. Voelker

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