X-Message-Number: 1122 Date: Mon, 10 Aug 1992 16:35 MST From: 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. * * * SYNCHROTRON ETCHES MICROSTRUCTURES FOR TINY 3-D COMPONENTS 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 * * * 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 devices. 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 Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=1122