| Only innovative and persistant companies
with brave teams accustomed to daring and challenging themselves,
and with a clear vision that beyond Moore there is another business
world worth exploring, have been successful. STMicroelectronics
has been among the few successful semiconductor companies that
invested in MEMS: millimeter-sized systems where not only electrons
are moving, but also fluids, cantilevers and membranes.
Micromachined sensors that detect acceleration, angular rate
and pressure are widely utilized in the automotive and medical
market. But only recently the development of small, low-power,
reliable and inexpensive micromachined sensors enabled their penetration
into the consumer market, as explained in the first paper of this
issue. The recent announcement of Nintendo about their innovative
Wii game controller, that uses an STMicroelectronics 3-axis accelerometer
to bring players into action, is a clear demonstration that MEMS
are not considered as prohibitively expensive components anymore.
Moreover the product is highly reliable, since the structural
material used to manufacture the accelerometer itself has excellent
mechanical properties as shown in the second and third paper of
this collection. This characterization work has been carried out
in close cooperation with Politecnico of Milano, CNR and Lancaster
University.
Micromachining technologies allow to realize not only sensors,
but also actuators. The fourth paper of this issue describes a
micromachining process suitable for the manufacturing of an electrostatic
actuator. The proper modeling of this actuator has been possible
thanks to the joint activity with Università di Pisa. The
fifth paper describes a numerical method that is fast and accurate
enough to allow the design of an electrostatic actuator used as
an optical switch or as a component of a Coriolis based gyroscope.
A vibrational gyroscope (paper #6) is a complex microsystem that
needs to be actuated in order to detect the angular rate. It is
much more complex than an accelerometer and thus the design of
a stable control loop is key for its performance. Università
di Trento contributed to the development of the proper servo-control
loop, while Università di Pavia helped to set up the optical
measurements (paper #7) that characterize the first prototypes.
Despite all the efforts in design and manufacturing, some micromachined
products designed for applications in the telecommunication market,
have not yet replaced existing technologies. In particular, the
well-known RF switch, well described in the last two articles
of this issue, has not entered the market.
But this is the game of research and development: It is impossible
to be 100% successful. However, it is important to learn the lesson.
We just need to learn fast, since “Nimble thought can jump
both sea and land” [W. Shakespeare].
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